humulene and Cognition-Disorders

While medical and recreational cannabis use is becoming more frequent among older adults, the neurocognitive consequences of cannabis use in this age group are unclear. The aim of this literature review was to synthesize and evaluate the current knowledge on the association of cannabis use during older-adulthood with cognitive function and brain aging. We reviewed the literature from old animal models and human studies, focusing on the link between use of cannabis in middle- and old-age and cognition. The report highlights the gap in knowledge on cannabis use in late-life and cognitive health, and discusses the limited findings in the context of substantial changes in attitudes and policies. Furthermore, we outline possible theoretical mechanisms and propose recommendations for future research. The limited evidence on this important topic suggests that use in older ages may not be linked with poorer cognitive performance, thus detrimental effects of early-life cannabis use may not translate to use in older ages. Rather, use in old ages may be associated with improved brain health, in accordance with the known neuroprotective properties of several cannabinoids. Yet, firm conclusions cannot be drawn from the current evidence-base due to lack of research with strong methodological designs.

Topics: Age Factors; Aged; Animals; Brain; Cannabinoids; Cannabis; Cognition; Cognition Disorders; Humans; Middle Aged

Marijuana is one of the most commonly used illicit drugs worldwide. In addition, use of synthetic cannabinoids is increasing, especially among adolescents and young adults. Although human studies have shown that the use of marijuana during pregnancy leads to adverse behavioral effects, such as deficiencies in attention and executive function in affected offspring, the rate of marijuana use among pregnant women is steadily increasing. Various aspects of human behavior including emotion, learning, and memory are dependent on complex interactions between multiple neurotransmitter systems that are especially vulnerable to alterations during the developmental period. Thus, exploration of neurotransmitter changes in response to prenatal cannabinoid exposure is crucial to develop an understanding of how homeostatic imbalance and various long-term neurobehavioral deficits manifest following the abuse of marijuana or other synthetic cannabinoids during pregnancy. Current literature confirms that vast alterations to neurotransmitter systems are present following prenatal cannabinoid exposure, and many of these alterations within the brain are region specific, time-dependent, and sexually dimorphic. In this review, we aim to provide a summary of observed changes to various neurotransmitter systems following cannabinoid exposure during pregnancy and to draw possible correlations to reported behavioral alterations in affected offspring.

Topics: Adrenergic Neurons; Animals; Brain; Cannabinoids; Cannabis; Cognition Disorders; Dopaminergic Neurons; Female; GABAergic Neurons; Humans; Male; Pregnancy; Prenatal Exposure Delayed Effects; Problem Behavior; Serotonergic Neurons; Sex Characteristics; Synaptic Transmission

Cannabinoids are proposed in a wide array of medical indications. Yet, the evaluation of adverse effects in controlled clinical studies, following the evidence-based model, has partly been bypassed. On the other hand, studies on the consequences of recreational use of cannabis and experimental studies bring some insights on the potential long-term consequences of cannabinoids use.. Epidemiological studies have consistently demonstrated that cannabis use is associated with a risk of persistent cognitive deficits and increased risk of schizophrenia-like psychoses. These risks are modulated by the dose and duration of use, on top of age of use and genetic factors, including partially shared genetic predisposition with schizophrenia. Experimental studies in healthy humans showed that cannabis and its principal psychoactive component, the delta-9-tetrahydrocannabinol (THC), could produce transient, dose-dependent, psychotic symptoms as well as cognitive effects, which can be attenuated by cannabidiol (CBD). Studies in rodents have confirmed these effects and shown that adolescent exposure results in structural changes and impaired synaptic plasticity, impacting fronto-limbic systems that are critically involved in higher brain functions. The endocannabinoid system plays an important role in brain maturation. Its over-activation by cannabinoid receptor type 1 agonists (e.g., THC) during adolescence and the resulting changes in neuroplasticity could alter brain maturation and cause long-lasting changes that persist in the adult brain.. Exposure to cannabinoids can have long-term impact on the brain, with an inter-individual variability that could be conveyed by personal and family history of psychiatric disorders and genetic background. Adolescence and early adulthood are critical periods of vulnerability.. The assessment of benefice-risk balance of medical use of cannabis and cannabinoids needs to carefully explore populations that could be more at-risk of psychiatric and cognitive complications.

Topics: Adolescent; Adult; Brain; Cannabidiol; Cannabinoid Receptor Agonists; Cannabinoids; Cannabis; Cognition Disorders; Cognitive Dysfunction; Dronabinol; Humans; Mental Disorders

Marijuana is becoming legal in an increasing number of states for both medical and recreational use. Considerable controversy exists regarding the public health impact of these changes. The evidence for the legitimate medical use of marijuana or cannabinoids is limited to a few indications, notably HIV/AIDS cachexia, nausea/vomiting related to chemotherapy, neuropathic pain, and spasticity in multiple sclerosis. Although cannabinoids show therapeutic promise in other areas, robust clinical evidence is still lacking. The relationship between legalization and prevalence is still unknown. Although states where marijuana use is legal have higher rates of use than nonlegal states, these higher rates were generally found even prior to legalization. As states continue to proceed with legalization for both medical and recreational use, certain public health issues have become increasingly relevant, including the effects of acute marijuana intoxication on driving abilities, unintentional ingestion of marijuana products by children, the relationship between marijuana and opioid use, and whether there will be an increase in health problems related to marijuana use, such as dependence/addiction, psychosis, and pulmonary disorders. In light of this rapidly shifting legal landscape, more research is urgently needed to better understand the impact of legalization on public health.

Topics: Automobile Driving; Cannabis; Cognition Disorders; Dronabinol; Humans; Illicit Drugs; Marijuana Abuse; Marijuana Smoking; Medical Marijuana; Opioid-Related Disorders; Prevalence; Psychotic Disorders; Public Health; United States

Cannabis use has been associated with impaired cognition during acute intoxication as well as in the unintoxicated state in long-term users. However, the evidence has been mixed and contested, and no systematic reviews of the literature on neuropsychological task-based measures of cognition have been conducted in an attempt to synthesize the findings. We systematically review the empirical research published in the past decade (from January 2004 to February 2015) on acute and chronic effects of cannabis and cannabinoids and on persistence or recovery after abstinence. We summarize the findings into the major categories of the cognitive domains investigated, considering sample characteristics and associations with various cannabis use parameters. Verbal learning and memory and attention are most consistently impaired by acute and chronic exposure to cannabis. Psychomotor function is most affected during acute intoxication, with some evidence for persistence in chronic users and after cessation of use. Impaired verbal memory, attention, and some executive functions may persist after prolonged abstinence, but persistence or recovery across all cognitive domains remains underresearched. Associations between poorer performance and a range of cannabis use parameters, including a younger age of onset, are frequently reported. Little further evidence has emerged for the development of tolerance to the acutely impairing effects of cannabis. Evidence for potential protection from harmful effects by cannabidiol continues to increase but is not definitive. In light of increasing trends toward legalization of cannabis, the knowledge gained from this body of research needs to be incorporated into strategies to minimize harm.

Topics: Attention; Cannabinoids; Cannabis; Cognition; Cognition Disorders; Executive Function; Humans; Marijuana Abuse; Marijuana Smoking; Memory; Neuropsychological Tests; Psychomotor Performance; Verbal Learning

Cannabis has been implicated as a risk factor for the development of schizophrenia, but the exact biological mechanisms remain unclear. In this review, we attempt to understand the neurobiological pathways that link cannabis use to schizophrenia. This has been an area of great debate; despite similarities between cannabis users and schizophrenia patients, the evidence is not sufficient to establish cause-and-effect. There have been advances in the understanding of the mechanisms of cannabis dependence as well as the role of the cannabinoid system in the development of psychosis and schizophrenia. The neurobiological mechanisms associated with the development of psychosis and effects from cannabis use may be similar but remain elusive. In order to better understand these associations, this paper will show common neurobiological and neuroanatomical changes as well as common cognitive dysfunction in cannabis users and patients of schizophrenia. We conclude that epidemiologic evidence highlights potential causal links; however, neurobiological evidence for causality remains weak.

Topics: Cannabinoids; Cannabis; Cognition Disorders; Humans; Marijuana Abuse; Psychotic Disorders; Risk Factors

Several studies have shown that Δ-9-THC the main psychoactive constituent of cannabis, can impair cognitive functions, especially attention, episodic memory, working memory and executive functions. These impairments have been related to the duration, frequency, dose and age at onset of cannabis use. Cognitive deficits may disappear with abstinence, but abnormalities may be long-lasting in subjects who began smoking cannabis before age 15. The lifetime prevalence of cannabis use disorders is about 1% in the general population. The main characteristics of cannabis use disorders are craving, persistent desire or unsuccessful efforts to cut down or control cannabis use, and persistent avoidance of familial, social occupational or recreational activities because of cannabis use. Nine prospective longitudinal studies in the generalpopulation have shown that cannabis use is associated with a two-fold increase in the risk of psychotic disorders, particularly schizophrenia, compared to controls. The risk of psychosis increases in a dose-related fashion. A higher risk of schizophrenia is predicted by earlier onset of cannabis use. The effects of cannabis are exerted primarily through THC interaction with cannabinoid (CB) 1 receptors in the brain. Cannabis exposure may disrupt the last steps of brain maturation, through the endocannabinoid system, thereby increasing the risk of psychosis during adolescence.

Topics: Adolescent; Animals; Cannabis; Cognition Disorders; Humans; Marijuana Smoking; Mental Disorders; Substance-Related Disorders

The amphetamine derivative 3, 4 Methylenedioxymethanphetamine (MDMA) is a powerful central nervous system stimulant that displays numerous pharmacological effects, including neurotoxicity. MDMA, or ecstasy, acts by inducing the release of different neurotransmitters depending on the animal species and, in particular, it produces the release of serotonin and dopamine. MDMA induces rewarding and reinforcing effects in rodents, primates and humans, and is currently consumed as an illicit psychostimulant among young people. One of the most reported side effects is the hyperthermic effect and the neurotoxicity on central serotonergic and dopaminergic neurons, depending on the species of animal. It seems that MDMA may also produce neurotoxic effects in humans. To date, the most consistent findings associated to MDMA consumption in humans relate to cognitive deficits in heavy users. MDMA when consumed as an illicit psychostimulant is commonly co-used with other abusers, being frequently associated with cannabinoids. The interaction between MDMA and cannabis effects is complex. Cannabis derivatives act on endocannabinoid system. Thus, at cellular levels, cannabinoids acting through CB1 cannabinoid receptors display opposite effects to those induced by MDMA, and they have been reported to develop neuroprotective actions, including the blockage of MDMA induced neurotoxicity, in laboratory animals. However, cannabis use is a recognized risk factor in the presentation and development of neuropsychiatric disorders, and also contributes to the development of psychological problems and cognitive failures observed in MDMA users. This paper represents a brief overview of the pharmacological interaction between MDMA and cannabis derivatives acting in the endocannabinoid system. We have evaluated recent findings in the literature of the most representative pharmacological effects displayed by both types of drugs. We analyze both, the synergic and opposite effects produced by these two compounds and we have found a gap regarding the negative consequences of long-term human consumption of MDMA alone or in combination with cannabis.

Topics: Amphetamine-Related Disorders; Animals; Cannabinoids; Cannabis; Cognition Disorders; Endocannabinoids; Humans; Marijuana Abuse; N-Methyl-3,4-methylenedioxyamphetamine; Reinforcement, Psychology; Reward; Time Factors

Topics: Cannabis; Cognition Disorders; Humans; Marijuana Abuse; Observer Variation

Cannabis is the most commonly used illicit drug among pregnant women. Since the endocannabinoid system plays a crucial role in brain development, maternal exposure to cannabis derivatives might result in long-lasting neurobehavioral abnormalities in the exposed offspring. It is difficult to detect these effects, and their underlying neurobiological mechanisms, in clinical cohorts, because of their intrinsic methodological and interpretative issues.. The present paper reviews relevant rodent studies examining the long-term behavioral consequences of exposure to cannabinoid compounds during pregnancy and/or lactation.. Maternal exposure to even low doses of cannabinoid compounds results in atypical locomotor activity, cognitive impairments, altered emotional behavior, and enhanced sensitivity to drugs of abuse in the adult rodent offspring. Some of the observed behavioral abnormalities might be related to alterations in stress hormone levels induced by maternal cannabis exposure.. There is increasing evidence from animal studies showing that cannabinoid drugs are neuroteratogens which induce enduring neurobehavioral abnormalities in the exposed offspring. Several preclinical findings reviewed in this paper are in line with clinical studies reporting hyperactivity, cognitive impairments and altered emotionality in humans exposed in utero to cannabis. Conversely, genetic, environmental and social factors could also influence the neurobiological effects of early cannabis exposure in humans.

Topics: Animals; Behavior, Animal; Brain; Cannabinoids; Cannabis; Cognition Disorders; Emotions; Female; Humans; Lactation; Motor Activity; Pregnancy; Prenatal Exposure Delayed Effects

Evidence that cannabis use impairs cognitive function in humans has been accumulating in recent decades. The purpose of this overview is to update knowledge in this area with new findings from the most recent literature.. Literature searches were conducted using the Web of Science database up to February 2010. The terms searched were: "cannabi*" or "marijuana", and "cogniti*" or "memory" or "attention" or "executive function", and human studies were reviewed preferentially over the animal literature.. Cannabis use impairs memory, attention, inhibitory control, executive functions and decision making, both during the period of acute intoxication and beyond, persisting for hours, days, weeks or more after the last use of cannabis. Pharmacological challenge studies in humans are elucidating the nature and neural substrates of cognitive changes associated with various cannabinoids. Long-term or heavy cannabis use appears to result in longer-lasting cognitive abnormalities and possibly structural brain alterations. Greater adverse cognitive effects are associated with cannabis use commencing in early adolescence.. The endogenous cannabinoid system is involved in regulatory neural mechanisms that modulate processes underlying a range of cognitive functions that are impaired by cannabis. Deficits in human users most likely therefore reflect neuroadaptations and altered functioning of the endogenous cannabinoid system.

Topics: Animals; Cannabis; Cognition Disorders; Humans; Marijuana Abuse; Time Factors

Impaired cognitive functioning, including deficits in working memory, is considered to be a core and disabling feature of schizophrenia that is difficult to treat. Deficits in working memory in schizophrenia are attributable, at least in part, to specific pathological alterations in the neuronal circuitry of the dorsolateral prefrontal cortex that involve, but are not restricted to, disturbances in glutamate, GABA, and dopamine neurotransmission. Cannabis use provides an example of an environmental exposure that may have a deleterious impact on these neurotransmitter systems and thereby contribute to worsening of cognitive functioning in schizophrenia. Increasing knowledge of the nature of the molecular alterations in these cortical circuits may lead to the development of new pathophysiologically informed treatment options for cognitive deficits in schizophrenia.

Topics: Animals; Cannabis; Cognition Disorders; Humans; Marijuana Abuse; Models, Neurological; Nerve Net; Neurons; Prefrontal Cortex; Schizophrenia

Whether "medical marijuana" (Cannabis sativa used to treat a wide variety of pathologic states) should be accorded the status of a legitimate pharmaceutical agent has long been a contentious issue. Is it a truly effective drug that is arbitrarily stigmatized by many and criminalized by the federal government? Or is it without any medical utility, its advocates hiding behind a screen of misplaced (or deliberately misleading) compassion for the ill? Should Congress repeal its declaration that smoked marijuana is without "current medical benefit"? Should cannabis be approved for medical use by a vote of the people as already has been done in 13 states? Or should medical marijuana be scientifically evaluated for safety and efficacy as any other new investigational drug? How do the competing--and sometimes antagonistic--roles of science, politics and prejudice affect society's attempts to answer this question? This article examines the legal, political, policy, and ethical problems raised by the recognition of medical marijuana by over one-fourth of our states although its use remains illegal under federal law. Although draconian punishment can be imposed for the "recreational" use of marijuana, I will not address the contentious question of whether to legalize or decriminalize the use of marijuana solely for its psychotropic effects, a fascinating and important area of law and policy that is outside the scope of this paper. Instead, the specific focus of this article will be on the conflict between the development of policies based on evidence obtained through the use of scientific methods and those grounded on ideological and political considerations that have repeatedly entered the longstanding debate regarding the legal status of medical marijuana. I will address a basic question: Should the approval of medical marijuana be governed by the same statute that applies to all other drugs or pharmaceutical agents, the Food, Drug, and Cosmetic Act (FD&C Act), after the appropriate regulatory agency, the Food and Drug Administration (FDA), has evaluated its safety and efficacy? If not, should medical marijuana be exempted from scientific review and, instead, be evaluated by the Congress, state legislatures, or popular vote? I will argue that advocacy is a poor substitute for dispassionate analysis, and that popular votes should not be allowed to trump scientific evidence in deciding whether or not marijuana is an appropriate pharmaceutical agent to use in modern

Topics: Cannabis; Cognition Disorders; Evidence-Based Medicine; Humans; Legislation, Drug; Lung Neoplasms; Phytotherapy; Politics; Public Policy; United States; United States Food and Drug Administration

The association between cannabis use and psychosis has long been recognized. Recent advances in knowledge about cannabinoid receptor function have renewed interest in this association. Converging lines of evidence suggest that cannabinoids can produce a full range of transient schizophrenia-like positive, negative, and cognitive symptoms in some healthy individuals. Also clear is that in individuals with an established psychotic disorder, cannabinoids can exacerbate symptoms, trigger relapse, and have negative consequences on the course of the illness. The mechanisms by which cannabinoids produce transient psychotic symptoms, while unclear may involve dopamine, GABA, and glutamate neurotransmission. However, only a very small proportion of the general population exposed to cannabinoids develop a psychotic illness. It is likely that cannabis exposure is a "component cause" that interacts with other factors to "cause" schizophrenia or a psychotic disorder, but is neither necessary nor sufficient to do so alone. Nevertheless, in the absence of known causes of schizophrenia, the role of component causes remains important and warrants further study. Dose, duration of exposure, and the age of first exposure to cannabinoids may be important factors, and genetic factors that interact with cannabinoid exposure to moderate or amplify the risk of a psychotic disorder are beginning to be elucidated. The mechanisms by which exposure to cannabinoids increase the risk for developing a psychotic disorder are unknown. However, novel hypotheses including the role of cannabinoids on neurodevelopmental processes relevant to psychotic disorders are being studied.

Topics: Association; Cannabis; Cognition Disorders; Humans; Marijuana Abuse; Neurotransmitter Agents; Psychotic Disorders; Schizophrenia

Understanding of the neurophysiological basis of cognitive, behavioural and perceptual disturbances associated with long-term cannabis use has grown dramatically. Exogenous cannabinoids alter the normative functioning of the endogenous cannabinoid system. This system is an important regulator of neurotransmission. Recent research has demonstrated abnormalities of the cannabinoid system in schizophrenia. The purpose of the present paper was to selectively review the links between cannabis use and psychosis, drawing upon recent epidemiological, clinical, cognitive, brain imaging and neurobiological research. The aim is to assist clinicians to probe more deeply into the newly unfolding world of cannabinoid physiology and to critically evaluate the potential role of cannabis in the onset and persistence of cognitive impairments and psychosis in otherwise healthy users and in schizophrenia.

Topics: Animals; Brain; Cannabinoid Receptor Modulators; Cannabinoids; Cannabis; Cognition Disorders; Humans; Psychoses, Substance-Induced; Schizophrenia; Schizophrenic Psychology

Cannabis has been used throughout human history. Delta (9)-tetrahydrocannabinol (THC) is the primary psychoactive component of cannabis. THC metabolises to 11-OH-THC and further to THC-acid, which is an inactive metabolite. We present an overview of the pharmacokinetics and pharmacodynamics of cannabinoids.. This article is based on selected literature with an emphasis on the pharmacodynamics of cannabinoids.. It has been demonstrated that mammalian tissues express cannabinoid receptors (CB1, CB2 and most probably CB3) and endogenous ligands for these. Knowledge of these receptors has lead to the development of components that stimulate (CB-agonists) or block their function (CB-antagonists). This opens up for the study of any potential therapeutic effects of cannabinoids. Research on a possible therapeutic potential of cannabinoids should however not overshadow the well-documented negative effects of cannabis; i.e. impaired cognitive functions, intoxication and an increased risk for development of psychosis and psychotic symptoms.

Topics: Cannabinoid Receptor Antagonists; Cannabinoids; Cannabis; Cognition Disorders; Dronabinol; Humans; Piperidines; Psychoses, Substance-Induced; Psychotropic Drugs; Pyrazoles; Receptors, Cannabinoid; Rimonabant; Risk Factors

Recent research has clarified a number of important questions concerning adverse effects of cannabis on health. A causal role of acute cannabis intoxication in motor vehicle and other accidents has now been shown by the presence of measurable levels of Delta(9)-tetrahydrocannabinol (THC) in the blood of injured drivers in the absence of alcohol or other drugs, by surveys of driving under the influence of cannabis, and by significantly higher accident culpability risk of drivers using cannabis. Chronic inflammatory and precancerous changes in the airways have been demonstrated in cannabis smokers, and the most recent case-control study shows an increased risk of airways cancer that is proportional to the amount of cannabis use. Several different studies indicate that the epidemiological link between cannabis use and schizophrenia probably represents a causal role of cannabis in precipitating the onset or relapse of schizophrenia. A weaker but significant link between cannabis and depression has been found in various cohort studies, but the nature of the link is not yet clear. A large body of evidence now demonstrates that cannabis dependence, both behavioral and physical, does occur in about 7-10% of regular users, and that early onset of use, and especially of weekly or daily use, is a strong predictor of future dependence. Cognitive impairments of various types are readily demonstrable during acute cannabis intoxication, but there is no suitable evidence yet available to permit a decision as to whether long-lasting or permanent functional losses can result from chronic heavy use in adults. However, a small but growing body of evidence indicates subtle but apparently permanent effects on memory, information processing, and executive functions, in the offspring of women who used cannabis during pregnancy. In total, the evidence indicates that regular heavy use of cannabis carries significant risks for the individual user and for the health care system.

Topics: Accidents, Traffic; Automobile Driving; Cannabis; Cardiovascular Diseases; Cognition Disorders; Cohort Studies; Dronabinol; Humans; Longitudinal Studies; Marijuana Abuse; Marijuana Smoking; Neurotoxicity Syndromes; Psychomotor Performance; Public Health; Respiratory Tract Diseases; Risk; Schizophrenia

To critically review cannabis research during the past 10 years in relation to rates of use, behavioral problems, and mental disorders in young people.. Studies published in English between 1994 and 2004 were identified through systematic searches of literature databases. The material was selectively reviewed focusing on child and adolescent data.. In the 27 years between 1976 and 2002, approximately half of all 12th graders had been exposed to cannabis in the United States. There is growing evidence that early and regular marijuana use is associated with later increases in depression, suicidal behavior, and psychotic illness and may bring forward the onset of schizophrenia. Most of the recent data reject the view that marijuana is used to self-medicate psychotic or depressive symptoms. Research on treatment is very limited.. Research on the mental health effects of cannabis has increased dramatically. Although doubts still remain about the role of cannabis in the causation of juvenile psychiatric disorder, the weight of the evidence points in the direction of early and regular cannabis use having substantial negative effects on psychosocial functioning and psychopathology.

Topics: Adolescent; Cannabis; Child; Cognition Disorders; Depression; Female; Humans; Male; Marijuana Smoking; Mental Disorders; Mental Health; Psychotic Disorders; Substance Withdrawal Syndrome; Suicide, Attempted

Cannabis is by far the illegal substance the most widely used by youth aged 12-25 years. One out of five persons living in France has already tried it once in his lifetime. Although the psychiatric symptoms as well as the cognitive and acute or chronic behavioral effects linked to repeated use of cannabis are well documented in the literature, search for persistent cognitive effects amongst chronic users has not provided convincing evidence because of methodological biases. The issue is nevertheless most crucial, especially amongst teenagers, due to the potential risks of deteriorated academic, social and occupational performance. The longer the exposure to the effects of the substance, the greater the risk of complications. Based on data reported in the literature, we report the cognitive effects associated with chronic use of cannabis as well as its social and educational consequences.

Topics: Adolescent; Adult; Cannabis; Child; Cognition Disorders; France; Humans; Neuropsychological Tests

Increasing prevalence of recreational cannabis use among the young population has stimulated debate on the possible effects of acute and longterm use.. To highlight recent knowledge of mechanisms of action, effects on psychomotor and cognitive performance, and health risks associated with cannabis consumption.. A brief review of recent literature on the prevalence of recreational cannabis use, the potency of modern cannabis preparations and the pharmacological actions of cannabis.. Cannabinoids derived from herbal cannabis interact with endogenous cannabinoid systems in the body. Actions on specific brain receptors cause dose-related impairments of psychomotor performance with implications for car and train driving, aeroplane piloting and academic performance. Other constituents of cannabis smoke carry respiratory and cardiovascular health risks similar to those of tobacco smoke.. Cannabis is not, as widely perceived, a harmless drug but poses risks to the individual and to society.

Topics: Cannabinoids; Cannabis; Cognition Disorders; Female; Humans; Male; Marijuana Abuse; Prevalence; Psychotropic Drugs; Respiratory Tract Diseases

Cannabis is commonly regarded as an innocuous drug and the prevalence of lifetime and regular use has increased in most developed countries. However, accumulative evidence highlights the risks of dependence and other adverse effects, particularly among people with pre-existing psychiatric disorders.. To re-evaluate the adverse effects of cannabis in the general population and among vulnerable individuals, including those with serious psychiatric disorders.. A wide-ranging review of the topics related to these issues. Results and conclusions An appreciable proportion of cannabis users report short-lived adverse effects, including psychotic states following heavy consumption, and regular users are at risk of dependence. People with major mental illnesses such as schizophrenia are especially vulnerable in that cannabis generally provokes relapse and aggravates existing symptoms. Health workers need to recognise, and respond to, the adverse effects of cannabis on mental health.

Topics: Affective Symptoms; Cannabis; Cognition Disorders; Female; Humans; Male; Marijuana Abuse; Psychoses, Substance-Induced; Psychotic Disorders; Psychotropic Drugs; Risk Factors; Substance Withdrawal Syndrome

Acute intoxication with cannabis clearly produces cognitive impairment, but it is less clear how long cognitive deficits persist after an individual stops regular cannabis use. Numerous methodologic difficulties confront investigators in the field attempting to assess the residual neuropsychologic effects of cannabis among heavy users, and these must be understood to properly evaluate available studies. At present, it appears safe to conclude that deficits in attention and memory persist for at least several days after discontinuing regular heavy cannabis use. Some of these deficits may be caused or exacerbated by withdrawal effects from the abrupt discontinuation of cannabis; these effects typically peak after 3 to 7 days of abstinence. It is less clear, however, whether heavy cannabis use can cause neurotoxicity that persists long after discontinuation of use. It seems likely that such long-term effects, if they exist, are subtle and not clinically disabling--at least in the majority of cases.

Topics: Attention; Brain; Cannabis; Cognition Disorders; Humans; Marijuana Abuse

The prevalence of substance abuse is elevated among schizophrenic patients. When free of illicit substances and sober, substance-abusing schizophrenic patients may have a better prognosis than other frequently hospitalized schizophrenic patients. However, the cost of substance abuse is great in terms of rehospitalization, homelessness, risk of other medical illness, disruption of social and vocational function, exacerbation of symptoms, suicide, and increased health care expenses. Important recent developments in medications for reducing substance abuse in nonschizophrenic populations make it timely to consider factors that might contribute to substance abuse among schizophrenic patients. This review will focus on substances most frequently abused by schizophrenic patients: nicotine, alcohol, cannabis, and psychostimulants. It concentrates on two conceptual foci: "self-medication hypotheses" and "comorbid addiction vulnerability hypotheses". The relationship between these hypotheses and possible pharmacotherapeutic approaches for substance-abusing schizophrenic patients will be considered.

Topics: Antipsychotic Agents; Basal Ganglia Diseases; Cannabis; Central Nervous System Stimulants; Cocaine; Cognition Disorders; Dopamine; Health Care Costs; Humans; Nicotine; Schizophrenia; Schizophrenic Psychology; Substance-Related Disorders

Topics: Animals; Cannabis; Catecholamines; Cognition Disorders; Humans; Lysergic Acid Diethylamide; Perceptual Disorders; Phytotherapy; Serotonin Antagonists; Substance-Related Disorders

To evaluate the sensitivity of a computerized cognitive-neuromotor test battery in assessing the effects of marijuana (delta-9-tetrahydrocannabinol [THC]), we conducted a study of 10 healthy male volunteers who were experienced marijuana smokers. After extensive training on the performance tasks, each subject was tested on three separate days after smoking a cigarette containing either 1.75% THC, 3.55% THC, or placebo according to a randomized double-blind repeated measures design. Testing was carried out before smoking and 30, 90, and 150 minutes after smoking the cigarette. Of the five tasks employed, the digit-symbol substitution test with memory and the reaction time task were the measures most sensitive to effects of marijuana. We examined the usefulness of the coefficient of variation and effect size as indices of sensitivity to be used across different types of tasks.

Topics: Adult; Blood Pressure; Cannabis; Cognition Disorders; Diagnosis, Computer-Assisted; Double-Blind Method; Dronabinol; Heart Rate; Humans; Male; Memory Disorders; Motor Skills; Reaction Time; Self-Assessment; Substance-Related Disorders; Task Performance and Analysis

Moreau de Tours's classical studies about haschisch had pointed out to a rich symptomatology: visual and auditive hallucinations preceded by the "primordial effect": "the dissociation of ideas". This delirious state was assimilated to dream. Modern studies, conducted with Delta-9-THC, in healthy voluntaries, again suggest the comparison or even the identity of the modifications caused by cannabis with sleep and dream. 10 mg of Delta-9-THC was absorbed in sesame oil by the voluntaries, and all of them presented disturbances of their vigilance, changes of their mood, now with euphoris and now with dysphoria, and slight psycho-sensorial alterations. The voluntaries EEG showed important and specific individual reactivity. Three subjects presented an arousal tendency, three other a greater towards sleep. Slight morphological changes have appeared, such as desynchronised periods, rapid shifts between I A, I B, II stages of sleep or an hypovariable I B stage of sedation with period of occular movements resembling to REM-stage.

Topics: Adult; Affect; Attention; Cannabis; Clinical Trials as Topic; Cognition Disorders; Confusion; Dreams; Dronabinol; Electroencephalography; Euphoria; Female; Hallucinations; Humans; Intelligence; Male; Middle Aged; Perceptual Disorders; Personality Disorders; Substance-Related Disorders

Topics: Adult; Affective Symptoms; Cannabis; Clinical Trials as Topic; Cognition Disorders; Depersonalization; Emotions; Euphoria; Humans; Male; Memory; Phytotherapy; Placebos; Serial Learning; Statistics as Topic; Time Perception

Topics: Cannabis; Cognition; Cognition Disorders; Cognitive Dysfunction; Humans; Parkinson Disease; Tremor

Cognitive impairment is among the core features of schizophrenia. In a healthy population, the cognitive deficit is often linked with cannabis abuse, and although the same would be expected in patients with schizophrenia, research has presented contradictory results.. Participants were patients with first-episode schizophrenia (FES) spectrum disorder who had been lifetime cannabis users (. FES patients using cannabis showed less impaired cognitive functioning with the most prominent difference in visual memory compared to FES non-users. However, they differed neither in the clinical assessment of general psychopathology, positive and negative symptoms, nor in medication from the patient's non-users. A comparison of the HC who used cannabis, and those who did not, revealed no sizeable differences in cognitive performance between the groups.. The results delivered supporting evidence for the trend of superior neurocognitive performance in FES patients with a lifetime history of cannabis use compared to non-using patients.

Topics: Cannabis; Cognition; Cognition Disorders; Humans; Marijuana Abuse; Schizophrenia

Preclinical and clinical studies suggest that males and females may be differentially affected by cannabis use. This study evaluated the interaction of cannabis use and biological sex on cognition, and the association between observed cognitive deficits and features of cannabis use.. Cognitive measures were assessed in those with regular, ongoing, cannabis use (N = 40; 22 female) and non-using peers (N = 40; 23 female). Intelligence, psychomotor speed, and verbal working memory were measured with the Wechsler Abbreviated Scale of Intelligence, Digit Symbol Test, and Digit Span and Hopkins Verbal Learning Test, respectively. Associations between cognitive measures and cannabis use features (e.g., lifetime cannabis use, age of initiation, time since last use of cannabis, recent high-concentration tetrahydrocannabinoid exposure) were also evaluated.. No main effects of group were observed across measures. Significant interactions between group and biological sex were observed on measures of intelligence, psychomotor speed, and verbal learning, with greatest group differences observed between males with and without regular cannabis use. Psychomotor performance was negatively correlated with lifetime cannabis exposure. Female and male cannabis use groups did not differ in features of cannabis use.. Findings suggest that biological sex influences the relationship between cannabis and cognition, with males potentially being more vulnerable to the neurocognitive deficits related to cannabis use.

Topics: Cannabis; Cognition; Cognition Disorders; Humans; Memory, Short-Term; Neuropsychological Tests; Verbal Learning

The literature on psychosis-relevant outcomes in cannabis users does not adequately address the confounding effects of other substance use/misuse and psychiatric disorders.. We studied a unique population for whom cannabis use is central and necessary to their way of life. They are forbidden from using other substances, including tobacco and alcohol. Their use of cannabis is heavy, chronic, and begins early. The cases were compared with matched controls who did not use cannabis, alcohol, or drugs. The controls were from the same location and shared similar beliefs and lifestyle, except for cannabis use. Attenuated psychosis-relevant phenomena were assessed with the Schizotypal Personality Questionnaire (SPQ) and cognitive functioning with a culture-neutral computerized cognitive battery.. Fifteen cases and 12 matched controls were studied. The cases averaged >30 000 lifetime cannabis exposures. Relative to controls, the cases had significantly higher mean (s.d.) SPQ scores 24 (14.32) v. 13 (8.92), p = 0.031; and poorer cognitive performance, reflected by a lower mean (s.d.) composite cognitive score -0.23 (0.32) v. +0.28 (0.52), p = 0.03. Moderate to large effect sizes were noted for differences in tests of attention, psychomotor speed, working memory, cognitive flexibility, visuo-spatial processing, and verbal memory. A subsample of cases had higher SPQ scores and worse cognitive performance than their siblings not using cannabis.. Heavy, chronic, and early cannabis use that is not confounded by other drug use is associated with psychosis-relevant phenomena and cognitive deficits. The findings are relevant to the evolving attitudes and laws about cannabis.

Topics: Adult; Cannabis; Case-Control Studies; Cognition; Cognition Disorders; Female; Humans; Male; Marijuana Abuse; Memory, Short-Term; Middle Aged; Neuropsychological Tests; Psychiatric Status Rating Scales; Psychotic Disorders; Siblings; Surveys and Questionnaires; Young Adult

Despite growing research, it remains unclear if cannabis use is associated with additive cognitive impairment in people with psychotic illness and whether exposure in early adolescence is associated with poorer cognitive performance in adulthood.. This cross-sectional study of a nationally representative sample of 1199 adults with psychotic illness compared current cognition (digit symbol coding) of 297 current users of cannabis (used in the past year), 460 past users (used previously but not in the past year) and 442 non-users (never used). Multiple logistic regression was used to examine whether cognitive performance of cannabis-user groups varied by exposure age and diagnosis (non-affective/affective psychoses).. Unadjusted analysis showed current cannabis users had significantly higher odds of impaired cognitive function compared to non-users (odds ratio=1.52, 95%CI=1.04-2.22). After adjusting for potential confounders, differences between the three groups were not significant. Exposure age was not significant in adjusted analysis. In participants with nonaffective psychoses, cognitive ability of current cannabis users did not differ from non-users. However, in participants with affective psychoses, using cannabis in the last year was a significant predictor of impaired cognitive function (odds ratio=2.25, 95%CI=1.05-4.84).. Among people with psychotic illness, there was no significant difference in cognitive function between current, past and non-users of cannabis. However, when we compared cognitive performance of the three cannabis groups by diagnostic grouping, current cannabis use had a significant negative relationship with cognitive function in people with affective psychoses, but not in those with non-affective psychoses. This finding requires replication and further investigation.

Topics: Adult; Age Factors; Cannabis; Cognition; Cognition Disorders; Cross-Sectional Studies; Female; Humans; Male; Marijuana Use; Neuropsychological Tests; Odds Ratio; Psychotic Disorders

Cannabis abuse in adolescence is associated with increased risk of psychotic disorders. Δ-9-tetrahydrocannabinol (THC) is the primary psychoactive component of cannabis. Disrupted-In-Schizophrenia-1 (DISC1) protein is a driver for major mental illness by influencing neurodevelopmental processes. Here, utilizing a unique mouse model based on host (DISC1) X environment (THC administration) interaction, we aimed at studying the pathobiological basis through which THC exposure elicits psychiatric manifestations. Wild-Type and dominant-negative-DISC1 (DN-DISC1) mice were injected with THC (10 mg/kg) or vehicle for 10 days during mid-adolescence-equivalent period. Behavioral tests were conducted to assess exploratory activity (open field test, light-dark box test) and cognitive function (novel object recognition test). Electrophysiological effect of THC was evaluated using acute hippocampal slices, and hippocampal cannabinoid receptor type 1 and brain-derived neurotrophic factor (BDNF) protein levels were measured. Our results indicate that THC exposure elicits deficits in exploratory activity and recognition memory, together with reduced short-term synaptic facilitation and loss of BDNF surge in the hippocampus of DN-DISC mice, but not in wild-type mice. Over-expression of BDNF in the hippocampus of THC-treated DN-DISC1 mice prevented the impairment in recognition memory. The results of this study imply that induction of BDNF following adolescence THC exposure may serve as a homeostatic response geared to maintain proper cognitive function against exogenous insult. The BDNF surge in response to THC is perturbed in the presence of mutant DISC1, suggesting DISC1 may be a useful probe to identify biological cascades involved in the neurochemical, electrophysiological, and behavioral effects of cannabis related psychiatric manifestations.

Topics: Adolescent; Animals; Animals, Newborn; Brain-Derived Neurotrophic Factor; Cannabis; Cognition; Cognition Disorders; Disease Models, Animal; Dronabinol; Hippocampus; Humans; Male; Mice; Mice, Inbred C57BL; Nerve Tissue Proteins; Psychotic Disorders

The most abused illicit drug in both the developing and the developed world is Cannabis disposing users to varying forms of personality disorders. However, the effects of cannabis on cortico-hippocampal architecture and cognitive behaviours still remain elusive.  The present study investigated the neuro-cognitive implications of oral cannabis use in rats. Eighteen adult Wistar rats were randomly grouped to three. Saline was administered to the control rats, cannabis (20 mg/kg) to the experimental group I, while Scopolamine (1 mg/kg. ip) was administered to the last group as a standard measure for the cannabis induced cognitive impairment. All treatments lasted for seven consecutive days. Open Field Test (OFT) was used to assess locomotor activities, Elevated Plus Maze (EPM) for anxiety-like behaviour, and Y maze paradigm for spatial memory and data subjected to ANOVA and T test respectively. Thereafter, rats were sacrificed and brains removed for histopathological studies. Cannabis significantly reduced rearing frequencies in the OFT and EPM, and increased freezing period in the OFT. It also reduced percentage alternation similar to scopolamine in the Y maze, and these effects were coupled with alterations in the cortico-hippocampal neuronal architectures. These results point to the detrimental impacts of cannabis on cortico-hippocampal neuronal architecture and morphology, and consequently cognitive deficits.

Topics: Administration, Oral; Animals; Behavior, Animal; Cannabis; Cerebral Cortex; Cognition; Cognition Disorders; Hippocampus; Maze Learning; Motor Activity; Plant Extracts; Plant Leaves; Rats, Wistar; Spatial Memory; Time Factors

There is some suggestion that heavy marijuana use during early adolescence (prior to age 17) may cause significant impairments in attention and academic functioning that remain despite sustained periods of abstinence. However, no longitudinal studies have examined whether both male and female adolescents who engage in low (less than once a month) to moderate (at least once a monthly) marijuana use experience increased problems with attention and academic performance, and whether these problems remain following sustained abstinence. The current study used within-individual change models to control for all potential pre-existing and time-stable confounds when examining this potential causal association in two gender-specific longitudinal samples assessed annually from ages 11 to 16 (Pittsburgh Youth Study N = 479; Pittsburgh Girls Study N = 2296). Analyses also controlled for the potential influence of several pertinent time-varying factors (e.g., other substance use, peer delinquency). Prior to controlling for time-varying confounds, analyses indicated that adolescents tended to experience an increase in parent-reported attention and academic problems, relative to their pre-onset levels, during years when they used marijuana. After controlling for several time-varying confounds, only the association between marijuana use and attention problems in the sample of girls remained statistically significant. There was no evidence indicating that adolescents who used marijuana experienced lingering attention and academic problems, relative to their pre-onset levels, after abstaining from use for at least a year. These results suggest that adolescents who engage in low to moderate marijuana use experience an increase in observable attention and academic problems, but these problems appear to be minimal and are eliminated following sustained abstinence.

Topics: Adolescent; Adolescent Behavior; Adolescent Development; Attention; Cannabis; Child; Cognition Disorders; Educational Measurement; Female; Humans; Longitudinal Studies; Male; Schools; Sex Factors

Topics: Adolescent; Adolescent Behavior; Cannabis; Cognition Disorders; Female; Humans; Legislation, Drug; Marijuana Abuse; Medical Marijuana; Mental Disorders; Risk; United States

We aimed to examine the association between lifetime cannabis use and estimates of both premorbid and current cognitive function in psychotic disorders in an Australian cohort.. In an Australian multicenter cohort, 1237 participants with an established ICD-10 diagnosis of psychotic disorder were categorised according to history of lifetime cannabis use (non-users, n=354; cannabis users, n=221; cannabis dependency, n=662). Groups were analyzed according to available indices of cognitive ability: the National Adult Reading Test - Revised (NART-R) for ability prior to illness onset; and the Digit Symbol Coding Test (DSCT) for current ability. Two-way analysis of variance was conducted without any covariate, followed by a two-way analysis of covariance (using age, age at onset of psychiatric illness, premorbid IQ and the Socio-Economic Index for Areas (SEIFA) rankings).. Whilst there appeared to be a significant association between cannabis use and mean DSCT (higher DSCT scores in cannabis using groups) F(2,1080)=9.478, p<0.001, η2=0.017), once covariates were used in the analysis there were no significant differences between groups in mean DSCT scores (F(2,1011)=0.929, p=0.395, η2=0.002). Similarly there were no differences between groups in mean NART scores once, age, age at illness onset and SEIFA rankings were used as covariates (F(2,1032)=1.617, p=0.199, η2=0.003).. Confounding variables underpin the association between cannabis use and cognitive function in psychotic disorders. Taken together, it would appear that cannabis use or dependence has no additive effect on cognitive dysfunction in these disorders.

Topics: Adult; Australia; Cannabis; Cognition; Cognition Disorders; Cohort Studies; Female; Humans; Intelligence; Intelligence Tests; Male; Marijuana Abuse; Marijuana Smoking; Psychological Tests; Psychotic Disorders; Schizophrenia; Schizophrenic Psychology

The prevalence of marijuana (MJ) use among youth and its legalization for medical or recreational use has intensified public health endeavors of understanding MJ effects on brain structure and function. Studies indicate that MJ use is related to impaired cognitive performance, and altered functional brain activation and chemistry in adolescents and adults, but MJ effects on brain morphology in emerging adults are less understood.. Fifteen MJ users (age 21.8±3.6, 2 females) and 15 non-user (NU) participants (age 22.3±3.5, 2 females) were included, demographically matched on age, education and alcohol use. High-resolution structural MR images were acquired at 3Tesla. Cortical thickness (CT) and volumetric analyses were performed using Freesurfer. A priori regions of interest (ROI) included orbitofrontal and cingulate cortices, amygdala, hippocampus and thalamus.. Whole brain CT analysis did not result in significant group differences in a priori ROIs but revealed MJ users had significantly less CT (i.e., thinness) in right fusiform gyrus (rFG) compared to NU (p<0.05). Thalamic volume was significantly smaller in MJ users compared to NU (right, p=0.05; left, p=0.01) and associated with greater non-planning (p<0.01) and overall impulsivity (p=0.04). There were no other group differences.. RFG cortical thinness and smaller thalamic volume in emerging adults is associated with MJ abuse. Furthermore, smaller thalamic volume associated with greater impulsivity contributes to growing evidence that the thalamus is neurobiologically perturbed by MJ use. Collectively, altered thalamic and rFG structural integrity may interfere with their known roles in regulating visuoperceptual and object information processing.

Topics: Adolescent; Adult; Amygdala; Atrophy; Cannabis; Case-Control Studies; Cerebral Cortex; Cognition Disorders; Female; Hippocampus; Humans; Impulsive Behavior; Magnetic Resonance Imaging; Male; Marijuana Abuse; Neuroimaging; Thalamus; Young Adult

Topics: Cannabis; Cerebral Angiography; Cognition Disorders; Female; Headache Disorders, Primary; Humans; Marijuana Smoking; Middle Aged; Nimodipine; Serotonin Agents; Stroke; Substance-Related Disorders; Treatment Outcome; Vasodilator Agents; Vasospasm, Intracranial

Marijuana is the most commonly used illicit substance in the United States. Use, particularly when it occurs early, has been associated with cognitive impairments in executive functioning, learning, and memory.. This study comprehensively measured cognitive ability as well as comorbid psychopathology and substance use history to determine the neurocognitive profile associated with young adult marijuana use. College-aged marijuana users who initiated use prior to age 17 (n = 35) were compared to demographically matched controls (n = 35).. Marijuana users were high functioning, demonstrating comparable IQs to controls and relatively better processing speed. Marijuana users demonstrated relative cognitive impairments in verbal memory, spatial working memory, spatial planning, and motivated decision making. Comorbid use of alcohol, which was heavier in marijuana users, was unexpectedly found to be associated with better performance in some of these areas.. This study provides additional evidence of neurocognitive impairment in the context of adolescent and young adult marijuana use. Findings are discussed in relation to marijuana's effects on intrinsic motivation and discrete aspects of cognition.

Topics: Adolescent; Adult; Age of Onset; Cannabis; Cognition Disorders; Female; Humans; Male; United States; Young Adult

Topics: Adolescent; Adolescent Behavior; Adult; Age Factors; Brain; Cannabinoids; Cannabis; Cognition; Cognition Disorders; Humans; Magnetic Resonance Imaging; Prefrontal Cortex; Risk Factors; Substance-Related Disorders

In the eastern Iran including Birjand and Greater Khorasan areas, a special traditional solid pie, locally called Majoon Birjandi (MB), is frequently abused by youngsters to induce a feel of high, special, euphoria, and energy. Cannabioid ingredients of this illicit solid lozenge are confirmed by clinical findings as well as positive urinary delta-q-tetrahydrocannabinol (THC) test. Because of its solid nature, it is easily smuggled and stored for a long time. Due to its localized usage in the eastern Iran, diagnosis of MB abuse is not known to toxicologists even from other parts of this country. We would like to bring to the attention of the readers the effects and cannabioid composition of this concoction and present the potential recreational ingestion root of processed cannabis for the first time.

Topics: Arrhythmias, Cardiac; Cannabis; Cognition Disorders; Drug Overdose; Eating; Hallucinations; Humans; Illicit Drugs; Iran; Panic Disorder

While neuropsychological deficits have been reported in healthy individuals who use street cannabis, data in patients with multiple sclerosis (MS) are lacking. Given that MS is associated with cognitive deterioration, the aim of this study was to determine the neuropsychological effects of cannabis use in this population.. Two groups, each of 25 patients with MS (cannabis users and nonusers), were administered the Minimal Assessment of Cognitive Function in MS battery of neuropsychological tests, the Hospital Anxiety and Depression Scale (HADS), and the Structured Clinical Interview for the DSM-IV Axis I Disorders (SCID-I). Group-matching and regression analysis were used to control for the effects of age, sex, education, premorbid intelligence, disability, and disease course and duration on cognitive function.. Cannabis users performed significantly more poorly than nonusers on measures of information processing speed, working memory, executive functions, and visuospatial perception. They were also twice as likely as nonusers to be classified as globally cognitively impaired. There were no between-group differences on the HADS measures of depression and anxiety or lifetime SCID-I psychiatric diagnoses.. This cross-sectional study provides empirical evidence that prolonged use of inhaled or ingested street cannabis in patients with MS is associated with poorer performance on cognitive domains commonly affected in this population. Whatever subjective benefits patients may derive from using street cannabis (e.g., pain and spasticity relief) should be weighed against the associated cognitive side effects.

Topics: Adolescent; Adult; Aged; Cannabis; Cognition; Cognition Disorders; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Multiple Sclerosis; Neuropsychological Tests; Phytotherapy; Plant Preparations; Prospective Studies; Psychiatric Status Rating Scales; Young Adult

Genetic variation in AKT1 may be associated with sensitivity to the psychotomimetic effects of cannabis as well as with increased risk for psychotic disorder following cannabis use. Investigation of the effect of this interaction on relevant intermediate phenotypes for psychosis, such as cognition, may help to clarify the underlying mechanism. Thus, verbal memory (visually presented Word Learning Task), sustained attention (Continuous Performance Test, CPT), AKT1 rs2494732 genotype, and cannabis use were examined in a large cohort of patients with psychotic disorder. No evidence was found for AKT1 × cannabis interaction on verbal memory. Cannabis use preceding onset of psychotic disorder did interact significantly with AKT1 rs2494732 genotype to affect CPT reaction time (β=8.0, SE 3.9, p=0.037) and CPT accuracy (β=-1.2, SE 0.4, p=0.003). Cannabis-using patients with the a priori vulnerability C/C genotype were slower and less accurate on the CPT, whereas cannabis-using patients with the T/T genotype had similar or better performance than non-using patients with psychotic disorder. The interaction was also apparent in patients with psychotic disorder who had not used cannabis in the 12 months preceding assessment, but was absent in the unaffected siblings of these patients and in healthy controls. In conclusion, cannabis use before onset of psychosis may have long-lasting effects on measures of sustained attention, even in the absence of current use, contingent on AKT1 rs2494732 genotype. The results suggest that long-term changes in cognition may mediate the risk-increasing effect of the AKT1 × cannabis interaction on psychotic disorder.

Topics: Adolescent; Adult; Cannabis; Cognition Disorders; Cohort Studies; Female; Genetic Variation; Humans; Male; Marijuana Abuse; Memory; Middle Aged; Proto-Oncogene Proteins c-akt; Psychotic Disorders; Young Adult

Topics: Animals; Cannabis; Cognition Disorders; Humans; Marijuana Abuse

Topics: Cannabis; Cognition Disorders; Humans; Multiple Sclerosis; Psychiatry

Cognitive deficits are commonly found both in patients with schizophrenia (SCH) and in people with cannabis use disorders (CUD). Surprisingly, some small recent studies reported better cognitive performance in SCH patients with comorbid cannabis use disorders (SCH + CUD) compared to other SCH patients.. The aim of the present study was to investigate the residual impact of CUD and specific patterns of consumption on cognition in a larger sample of SCH + CUD patients.. We administered a cognitive test battery to 34 SCH and 35 currently abstinent SCH + CUD patients. We explored the association between patterns of cannabis consumption and cognitive performance. Potential confounds with influence on cognitive ability were assessed and controlled for.. SCH + CUD patients had poorer academic achievements and lower vocabulary scores, but they performed better in tests of verbal and working memory, visuomotor speed and executive function (p < .05). More frequent cannabis use was associated with better performance in attention and working memory tasks.. Although our findings might be interpreted as beneficial effect of cannabis use on cognition in patients with schizophrenia, we favorise an alternative interpretation: in our view, the better cognitive functioning of SCH + CUD patients may rather reflect a relatively lower vulnerability to psychosis compared to the SCH group. Lower vulnerability may correspond to a higher level of functioning such as cognitive ability. This conclusion is consistent with the view of cannabis playing a critical role in the manifestation of psychosis in at least some of the SCH + CUD patients.

Topics: Adult; Analysis of Variance; Cannabis; Chi-Square Distribution; Cognition Disorders; Female; Humans; Male; Marijuana Abuse; Neuropsychological Tests; Schizophrenia; Statistics, Nonparametric

Adult human studies suggest frontal dysfunction associated with chronic marijuana (MJ) use, but due to continued neuromaturation, adult studies may not generalize to adolescents. This study characterized prefrontal cortex (PFC) morphometry in chronic MJ-using adolescents following 1 month of monitored abstinence. Data were collected from MJ users (n = 16) and controls (n = 16) aged 16-18. Extensive exclusionary criteria included co-morbid psychiatric and neurologic disorders. Substance use and anatomical measures were collected after 28 days of monitored abstinence. PFC volumes were ascertained from manual tracing by reliable raters on high-resolution magnetic resonance images. After controlling for lifetime alcohol use, gender and intracranial volume, MJ users did not differ from controls in PFC volume. However, marginal group-by-gender interactions were observed (P < 0.09): female MJ users demonstrated comparatively larger PFC volumes while male MJ users had smaller volumes compared with same-gender controls. Further, group status and total PFC volume interacted in predicting executive functioning (P < 0.05). Among MJ users, smaller PFC total volume was associated with better executive functioning while the opposite pattern was seen among the controls. These preliminary results indicate that gender may moderate the relationship between MJ use and PFC morphometry. Given the relationship between larger PFC total volumes and poorer executive functioning among MJ users, female MJ users may be at increased risk for neurocognitive consequences. Future research will measure PFC gray and white matter separately and follow boys and girls over adolescence to examine the influence of MJ use on neurodevelopment.

Topics: Adolescent; Cannabis; Cognition Disorders; Executive Function; Female; Humans; Magnetic Resonance Imaging; Male; Marijuana Abuse; Neuropsychological Tests; Prefrontal Cortex; Prevalence; Severity of Illness Index; Sex Factors; Substance Withdrawal Syndrome

Controversy exists regarding whether young people at risk for schizophrenia are at increased risk of adverse mental effects of cannabis use.. We examined cannabis use and mental health functioning in three groups of young people aged 14-21; 36 non-psychotic siblings of adolescents with schizophrenia (genetic high risk group), 25 adolescents with attention deficit hyperactivity disorder (ADHD) and 72 healthy controls. The groups were sub-divided into 'users' and 'non-users' of cannabis based on how often they had used cannabis previously. Mental health functioning was quantified by creating a composite index derived from scores on the Schizotypal Personality Questionnaire (SPQ), Strengths and Difficulties Questionnaire (SDQ) and Global Assessment of Function (GAF).. A significant positive association between cannabis use and mental health disturbance was confined to young people at genetic high risk for schizophrenia. To determine whether the relationship was specific to particular dimensions of mental health function, a second composite index was created based on scores from the SPQ Disorganisation and SDQ hyperactivity-inattention sub-scales. Again, there was a significant positive association between cannabis use and factor scores which was specific to the genetic high risk group. There was a trend for this association to be negative in the ADHD group (p=0.07).. The findings support the view that young people at genetic high risk for schizophrenia are particularly vulnerable to mental health problems associated with cannabis use. Further research is needed to investigate the basis of relationships between cannabis and mental health in genetically vulnerable individuals.

Topics: Adolescent; Adult; Attention Deficit Disorder with Hyperactivity; Cannabis; Cognition Disorders; Control Groups; Cross-Sectional Studies; Female; Genetic Predisposition to Disease; Humans; Male; Marijuana Abuse; Neuropsychological Tests; Prevalence; Psychiatric Status Rating Scales; Psychology, Adolescent; Risk Factors; Schizophrenia; Schizophrenic Psychology; Severity of Illness Index; Surveys and Questionnaires

A large number of studies, reviews and meta-analyses have reported cognitive deficits in ecstasy users. However most ecstasy users are polydrug users, and therefore it cannot be excluded that these deficits are (partly) the result of drugs other than ecstasy. The current study, part of the Netherlands XTC Toxicity (NeXT) study, investigates the specific sustained effects of ecstasy relative to amphetamine, cocaine and cannabis on the brain using neuropsychological examination.. A stratified sample of 67 subjects with such a variation in type and amount of drug use was included that correlations between the consumption of the various drugs were relatively low allowing stepwise linear multiple regression analyses to differentiate between the effects of ecstasy and those of other substances. Subjects were assessed with neuropsychological tests measuring attention, working memory, verbal and visuospatial memory, and visuospatial ability.. Ecstasy use [mean 327 (S.D.=364) tablets in lifetime] had a specific significant dose-related negative effect on verbal delayed recall after adjusting for the use of other drugs.. These findings strongly suggest a specific sustained negative effect of ecstasy use on verbal memory. The clinical relevance is not immediately clear, because test performance generally remained within the normal range. However the magnitude of the effect is substantial (d>0.5) and long-term consequences cannot be excluded.

Topics: Adolescent; Adult; Amphetamine; Attention; Cannabis; Central Nervous System Stimulants; Cocaine; Cognition; Cognition Disorders; Female; Hallucinogens; Humans; Illicit Drugs; Male; Memory, Short-Term; N-Methyl-3,4-methylenedioxyamphetamine; Netherlands; Neuropsychological Tests; Space Perception; Substance-Related Disorders; Verbal Behavior; Visual Perception

Although there have been several reports linking ecstasy use with lowered cognitive function, much previous research suffers from substantial methodological limitations. The present study aimed to examine associations between ecstasy use and higher-level cognitive functions, using a larger sample size than most previous research and better controlling for a range of potential confounds.. A cross-sectional cohort design assessed 45 currently abstinent ecstasy polydrug users (EP), 48 cannabis polydrug users (CP) and 40 legal drug users (LD). Standardized neuropsychological tests were used to measure attention, verbal, visual and working memory and executive function. Prospective memory function was also assessed.. It was not possible to discriminate between groups on the basis of the cognitive functions assessed. Regression analyses showed an inverse association between lifetime dose of ecstasy and verbal memory performance. A combination of drug-use variables, including measures of ecstasy use, contributed to prediction of attention/working memory. However, individual associations were small, explaining 1-6% of variance in cognitive scores.. Although the results suggest that heavy use of ecstasy is associated with some lowering of higher-level cognitive functions, they do not indicate a clinical picture of substantial cognitive dysfunction.

Topics: Adult; Affect; Attention; Cannabis; Cognition; Cognition Disorders; Cohort Studies; Cross-Sectional Studies; Dose-Response Relationship, Drug; Female; Humans; Male; Memory; Memory, Short-Term; N-Methyl-3,4-methylenedioxyamphetamine; Neuropsychological Tests; Predictive Value of Tests; Severity of Illness Index; Students; Substance-Related Disorders; Verbal Behavior

A significant minority of patients with multiple sclerosis (MS) use cannabis, yet no study has examined the possible effects on mentation. Here, we report the emotional and cognitive correlates of street cannabis use in patients with MS.. A sample of 140 consecutive patients with MS were interviewed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) Axis I disorders (SCID-IV) from which details of cannabis use were recorded. Cognition was assessed using the Neuropsychological Battery for MS supplemented with the Symbol Digit Modalities Test (SDMT), an index of information processing speed, working memory, and sustained attention.. Ten subjects (7.7%) were defined as current cannabis users based on use within the last month. Compared to non-cannabis users (n = 130), they were younger (p = 0.001). Each of the 10 current cannabis users was matched on demographic and disease variables to four subjects with MS who did not use cannabis (total control sample n = 40). Group comparisons revealed that the proportion of patients meeting DSM-IV criteria for a psychiatric diagnosis was higher in cannabis users (p = 0.04). In addition, on the SDMT, cannabis users had a slower mean performance time (p = 0.006) and a different pattern of response compared to matched controls (group x time interaction; p = 0.001).. Inhaled cannabis is associated with impaired mentation in patients with multiple sclerosis, particularly with respect to cognition. Future studies are required to clarify the direction of this relationship.

Topics: Adult; Cannabis; Cognition Disorders; Diagnostic and Statistical Manual of Mental Disorders; Female; Humans; Male; Marijuana Smoking; Middle Aged; Multiple Sclerosis; Neuropsychological Tests

Ecstasy (street name for [+/-]-3,4-methylenedioxymethamphetamine [MDMA]) use has been associated with cognitive deficits, especially in verbal memory. However, owing to the cross-sectional and retrospective nature of currently available studies, questions remain regarding the causal direction and clinical relevance of these findings.. To examine the relationship between Ecstasy use and subsequent cognitive performance.. A prospective cohort study in Ecstasy-naive subjects with a high risk for future first Ecstasy use, as part of the Netherlands XTC Toxicity study. The initial examination took place between April 10, 2002, and April 28, 2004; follow-up was within 3 years after the initial examination.. One hundred eighty-eight healthy Ecstasy-naive volunteers (mean age, 22 years) were recruited. Of these, 58 subjects started using Ecstasy (mean cumulative dose, 3.2 tablets; median cumulative dose, 1.5 tablets). They were compared with 60 persistent Ecstasy-naive subjects matched on age, sex, intelligence, and use of substances other than Ecstasy. Differences in cognition between Ecstasy users and Ecstasy-naive subjects were adjusted for differences in cannabis and other recreational drug use.. Change scores between the initial examination and follow-up on neurocognitive tests measuring attention, working memory, verbal and visual memory, and visuospatial ability.. At the initial examination, there were no statistically significant differences in any of the neuropsychological test scores between persistent Ecstasy-naive subjects and future Ecstasy users. However, at follow-up, change scores on immediate and delayed verbal recall and verbal recognition were significantly lower in the group of incident Ecstasy users compared with persistent Ecstasy-naive subjects. There were no significant differences on other test scores.. Our findings suggest that even a first low cumulative dose of Ecstasy is associated with decline in verbal memory. Although the performance of the group of incident Ecstasy users is still within the normal range and the immediate clinical relevance of the observed deficits is limited, long-term negative consequences cannot be excluded.

Topics: Adult; Attention; Cannabis; Cognition; Cognition Disorders; Cohort Studies; Female; Follow-Up Studies; Humans; Illicit Drugs; Male; Memory; Memory Disorders; N-Methyl-3,4-methylenedioxyamphetamine; Netherlands; Neuropsychological Tests; Prospective Studies; Risk Factors; Substance-Related Disorders; Verbal Behavior

Recent research suggests that not only does the use of recreational drugs impact on working memory functioning, but more ;everyday' aspects of memory (e.g. remembering to do something in the future) are also affected. Forty-three ecstasy-polydrug users and 51 non-ecstasy users were recruited from a university population. Each participant completed the Cognitive Failures Questionnaire (CFQ) and Everyday Memory Questionnaire (EMQ). Of these, 28 ecstasy-polydrug users and 35 non-ecstasy users completed the Prospective Memory Questionnaire (PMQ). In addition, an objective measure of cognitive failures (the CFQ-for-others) was completed by friends of participants. With the exception of the CFQ-for-others, in each regression equation, cannabis emerged as the only significant predictor of everyday and prospective memory deficits. Significant correlations were found between the different indicators of everyday memory and various measures of illicit drug use. Cannabis featured prominently in this respect. The present study provides further support for cannabis related deficits in aspects of everyday memory functioning. Ecstasy may aLso be associated with cognitive slips, but not to the same extent as cannabis.

Topics: Adult; Cannabis; Cognition Disorders; Female; Hallucinogens; Humans; Illicit Drugs; Linear Models; Male; Memory; Memory Disorders; N-Methyl-3,4-methylenedioxyamphetamine; Substance-Related Disorders; Surveys and Questionnaires

Topics: Adolescent; Alcoholism; Amygdala; Brain; Cannabis; Cognition Disorders; Hippocampus; Humans; Magnetic Resonance Imaging; Marijuana Abuse; Saliva

A modified Stroop color-word interference paradigm was used to investigate the effects of recreational ecstasy (MDMA) use on central executive inhibitory processes. Ecstasy users who also used cannabis were compared with non-users matched for cannabis consumption and with non-drug users on a Stroop task in which standard color-word interference trials were interspersed with trials in which the target color was the same as the distractor word on the immediately preceding trial. Ecstasy's effects on standard inhibition (conscious suppression of a prepotent response pattern--responsible for Stroop interference) could thus be contrasted with its effect on the short-term, unconscious, inhibitory process responsible for suppression of the preceding distractor word (negative priming). Neither drug group differed from the non-drug users in level of Stroop interference but ecstasy users showed reduced negative priming compared to the cannabis users and non-drug users. The loss of inhibition in the ecstasy users was not related to impulsivity assessed by two standard scales since these were similar in both drug-user groups and raised relative to the non-drug users. It is argued that previous failures to demonstrate loss of inhibition could be partly due to the fact that standard executive function tests, such as the Stroop, are unable to differentiate between sub-types of inhibition, only some of which may be affected by ecstasy use.

Topics: Adult; Cannabis; Cognition Disorders; Female; Humans; Impulsive Behavior; Inhibition, Psychological; Male; N-Methyl-3,4-methylenedioxyamphetamine; Neuropsychological Tests; Prevalence

Topics: Brain; Cannabis; Cognition Disorders; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Tolerance; Humans; Marijuana Abuse

Topics: Brain; Cannabis; Chronic Disease; Cognition Disorders; Drug Administration Schedule; Humans; Marijuana Abuse; Neuropsychological Tests; Substance Withdrawal Syndrome; Time

Cannabis is currently the most commonly used illegal psychoactive substance amongst young people aged between 15 and 24, and it seems that 5% of this age group is addicted to it. Many research teams focused particularly on the cognitive disorders caused by cannabis use. Amongst the cognitive functions considered, memory-related, attention-related, psychomotor and motivation-related functions were proved deteriorated by acute and chronic cannabis use; a very important point, especially among teenagers, as possible alteration at the social and academic level could be the outcome. However studies on long-term and persistent cognitive effects haven't provided convergent conclusions. Methodological differences could partly affect these observations. Therefore it seems necessary to develop studies with larger samples.

Topics: Adolescent; Adult; Age Factors; Cannabis; Cognition Disorders; Humans; Marijuana Abuse; Research; Risk; Risk Factors; Schizophrenia; Time Factors

Topics: Brain; Cannabis; Cerebrovascular Circulation; Cerebrovascular Disorders; Clinical Trials as Topic; Cognition Disorders; Dose-Response Relationship, Drug; Humans; Marijuana Abuse; Plant Preparations; Reproducibility of Results; Substance Withdrawal Syndrome

Despite extensive research on the effects of cannabis on cognitive and motor performance, studies administering computerised cognitive batteries and pencil-and-paper tests have not provided consistent results. Contributing factors are the broad range of tests used, together with a lack of sensitivity for assessing specific cognitive processes. This study for the first time assesses a very early cognitive process, information processing, that is sufficiently fundamental as to be immune from higher cognitive, motivational, and social processes. Information processes are thought to represent the basic building blocks of higher order cognitive processes. The inspection time (IT) task was used to investigate the effects of acute and subacute cannabis use on information processing in 22 heavy users, compared to 22 noncannabis-using controls. Findings indicate that users in the subacute state display significantly slowed information-processing speeds (longer ITs) compared to controls. Paradoxically, this deficit appears to be normalised whilst users are in the acute state. These results may be explained as a withdrawal effect, but may also be due to tolerance development as a result of long-term cannabis use. Furthermore, these results may assist in providing an explanation for the development of dependence with chronic cannabis users.

Topics: Acute Disease; Adult; Cannabis; Cognition Disorders; Female; Humans; Male; Marijuana Abuse; Neuropsychological Tests; Reaction Time; Substance Withdrawal Syndrome

Topics: Cannabis; Cognition; Cognition Disorders; Hallucinogens; Humans; Illicit Drugs; N-Methyl-3,4-methylenedioxyamphetamine; Substance-Related Disorders

The binocular depth inversion illusion (BDII) has been shown to be a sensitive measure of impaired visual information processing under conditions including cannabinoid-intoxicated states, alcohol withdrawal, sleep deprivation, and in patients with positive symptoms of schizophrenia. This study assessed whether the BDII could detect subtle cognitive impairment due to regular cannabis use by comparing 10 regular cannabis users and 10 healthy controls from the same community sources, matched for age, sex, and premorbid IQ. Subjects were also compared on measures of executive functioning, memory, and personality. Regular cannabis users were found to have significantly higher BDII scores for inverted images. This was not due to a problem in the primary processing of visual information, as there was no significant difference between the groups for depth perception of normal images. There was no relationship between BDII scores for inverted images and time since last dose, suggesting that the measured impairment of BDII more closely reflected chronic than acute effects of regular cannabis use. There were no significant differences between the groups for other neuropsychological measures of memory or executive function. A positive relationship was found between EPQ-R-psychoticism and cannabis, tobacco, and alcohol use. Cannabis users also used significantly larger amounts of alcohol. However, no relationship was found between BDII scores and drug use other than cannabis or psychoticism. Compared to the other neuropsychological tests used, the BDII appears to be a more sensitive tool for the detection of subtle impairments in visual information processing related to chronic cannabis use.

Topics: Adult; Cannabis; Cognition Disorders; Female; Humans; Linear Models; Male; Marijuana Abuse; Neuropsychological Tests; Photic Stimulation; Vision Disparity

Assessing marijuana's impact on intelligence quotient (IQ) has been hampered by a lack of evaluation of subjects before they begin to use this substance. Using data from a group of young people whom we have been following since birth, we examined IQ scores before, during and after cessation of regular marijuana use to determine any impact of the drug on this measure of cognitive function.. We determined marijuana use for seventy 17- to 20-year-olds through self-reporting and urinalysis. IQ difference scores were calculated by subtracting each person's IQ score at 9-12 years (before initiation of drug use) from his or her score at 17-20 years. We then compared the difference in IQ scores of current heavy users (at least 5 joints per week), current light users (less than 5 joints per week), former users (who had not smoked regularly for at least 3 months) and non-users (who never smoked more than once per week and no smoking in the past two weeks).. Current marijuana use was significantly correlated (p < 0.05) in a dose-related fashion with a decline in IQ over the ages studied. The comparison of the IQ difference scores showed an average decrease of 4.1 points in current heavy users (p < 0.05) compared to gains in IQ points for light current users (5.8), former users (3.5) and non-users (2.6).. Current marijuana use had a negative effect on global IQ score only in subjects who smoked 5 or more joints per week. A negative effect was not observed among subjects who had previously been heavy users but were no longer using the substance. We conclude that marijuana does not have a long-term negative impact on global intelligence. Whether the absence of a residual marijuana effect would also be evident in more specific cognitive domains such as memory and attention remains to be ascertained.

Topics: Adolescent; Adult; Age Factors; Analysis of Variance; Cannabis; Cognition; Cognition Disorders; Female; Humans; Intelligence Tests; Longitudinal Studies; Male; Ontario; Predictive Value of Tests; Probability; Reference Values; Risk Assessment; Risk Factors; Sampling Studies; Substance-Related Disorders; Time Factors

Topics: Automobile Driving; Cannabis; Cognition Disorders; Humans; Marijuana Abuse; Prevalence; Psychomotor Performance; Public Health; Respiration Disorders; Schizophrenia

The purpose of this study was to investigate possible adverse effects of cannabis use on cognitive decline after 12 years in persons under age 65 years. This was a follow-up study of a probability sample of the adult household residents of East Baltimore. The analyses included 1,318 participants in the Baltimore, Maryland, portion of the Epidemiologic Catchment Area study who completed the Mini-Mental State Examination (MMSE) during three study waves in 1981, 1982, and 1993-1996. Individual MMSE score differences between waves 2 and 3 were calculated for each study participant. After 12 years, study participants' scores declined a mean of 1.20 points on the MMSE (standard deviation 1.90), with 66% having scores that declined by at least one point. Significant numbers of scores declined by three points or more (15% of participants in the 18-29 age group). There were no significant differences in cognitive decline between heavy users, light users, and nonusers of cannabis. There were also no male-female differences in cognitive decline in relation to cannabis use. The authors conclude that over long time periods, in persons under age 65 years, cognitive decline occurs in all age groups. This decline is closely associated with aging and educational level but does not appear to be associated with cannabis use.

Topics: Adult; Aged; Aging; Cannabis; Catchment Area, Health; Cognition; Cognition Disorders; Female; Follow-Up Studies; Humans; Male; Marijuana Abuse; Mental Status Schedule; Middle Aged; Probability; Socioeconomic Factors

Establishment of residual cognitive and psychotic effects (effects present at the time that all active cannabinoids are eliminated from the body) putatively produced by prolonged heavy cannabis use is difficult, because of many confounding variables like slow elimination of active cannabinoids, lack of supervision during abstinence, poor use of well-matched control groups and the presence of withdrawal symptoms. Residual cognitive effects were observed in some but not in all tests after prolonged heavy cannabis use. The effects were mostly mild. The relationship of cannabis use, psychotic effects and schizophrenia was unclear; the cannabis conceivably gave relief, but it also appeared that cannabis caused schizophrenia in young people and (or) enhanced the symptoms, especially in young people poorly able to cope with stress or in whom the antipsychotic therapy was unsuccessful.

Topics: Adolescent; Cannabinoids; Cannabis; Chronic Disease; Cognition; Cognition Disorders; Confounding Factors, Epidemiologic; Diagnosis, Differential; Drug Residues; Female; Humans; Male; Psychoses, Substance-Induced; Schizophrenia; Substance Withdrawal Syndrome; Substance-Related Disorders

Topics: Australia; Cannabis; Cognition Disorders; Ethics, Professional; Humans; Research; Substance-Related Disorders

Topics: Adolescent; Adult; Brain Diseases; Cannabis; Cognition Disorders; Female; Hallucinations; Humans; Male; Paranoid Disorders

Topics: Adolescent; Cannabis; Child; Child, Preschool; Chronic Disease; Cognition Disorders; Female; Humans; Male; Substance-Related Disorders

Topics: Affective Symptoms; Attitude; Awareness; California; Cannabis; Cognition Disorders; Drug and Narcotic Control; Female; Humans; Male; Motivation; Personality Disorders; Self Concept; Self-Assessment; Social Perception; Substance-Related Disorders

Topics: Adult; Age Factors; Animals; Atrophy; Brain; Brain Diseases; Cannabis; Cognition Disorders; Haplorhini; Humans; Rats; Substance-Related Disorders; Time Factors

Topics: Adolescent; Anxiety; Cannabis; Cognition Disorders; Female; Humans; Lysergic Acid Diethylamide; Male

Topics: Adult; Appetite; Attitude; Cannabis; Chemical and Drug Induced Liver Injury; Chronic Disease; Cognition Disorders; Dronabinol; Emotions; Humans; Inhibition, Psychological; Mental Disorders; Motivation; Movement Disorders; Nutrition Disorders; Phytotherapy; Respiratory System; Sexual Behavior; Social Behavior; Space Perception; Substance-Related Disorders; Tachycardia; Thinking; Time Factors; Time Perception

Topics: Adolescent; Adult; Amphetamine; Barbiturates; Cannabis; Cocaine; Cognition Disorders; Factor Analysis, Statistical; Hallucinogens; Humans; Male; Morphinans; Perceptual Disorders; Psychological Tests; Socioeconomic Factors; Substance Withdrawal Syndrome; Substance-Related Disorders

Topics: Adult; Cannabis; Cognition Disorders; Ethanol; Germany, West; Humans; International Cooperation; Legislation, Drug; Lysergic Acid Diethylamide; Male; Mental Disorders; Military Medicine; Military Personnel; Psychoses, Substance-Induced; Schizophrenia; Schizotypal Personality Disorder; Substance-Related Disorders; United States

Topics: Adolescent; Adult; Amphetamine; Cannabis; Chronic Disease; Cognition Disorders; Female; Hallucinogens; Humans; Lysergic Acid Diethylamide; Male; Personality Disorders; Psychoses, Substance-Induced; Rorschach Test; Schizophrenia; Schizophrenic Psychology; Substance-Related Disorders; Thinking; Time Factors

Topics: Acute Disease; Adult; Aggression; Amnesia; Antipsychotic Agents; Cannabis; Cognition Disorders; Delusions; Hospitalization; Humans; Hypnotics and Sedatives; Male; Mental Disorders; Motor Activity; Personality; Phenothiazines; Psychoses, Substance-Induced; Substance-Related Disorders; Time Factors

Topics: Cannabis; Cognition Disorders; Culture; Humans; Psychoses, Substance-Induced; Research; Socioeconomic Factors; Substance-Related Disorders; World Health Organization

Topics: Cannabis; Cognition Disorders; Female; Hallucinogens; Human Experimentation; Humans; Lysergic Acid Diethylamide; Male; Personality Inventory; Psychoses, Substance-Induced; Stress, Psychological; Substance-Related Disorders; Time Factors

Topics: Adolescent; Adult; Cannabis; Cognition Disorders; Humans; Personality Disorders; Substance-Related Disorders

Topics: Adolescent; Adult; Age Factors; Alcohol Drinking; Alkaloids; Austria; Cannabis; Cognition Disorders; Criminal Psychology; Depressive Disorder, Major; Epilepsy, Tonic-Clonic; Histrionic Personality Disorder; Humans; Hypnotics and Sedatives; Intelligence; Juvenile Delinquency; Personality; Psychoses, Substance-Induced; Psychotherapy; Social Class; Socioeconomic Factors; Substance Withdrawal Syndrome; Substance-Related Disorders; Unconscious, Psychology

Topics: Adolescent; Adult; Anxiety; Cannabis; Cognition Disorders; Community Health Services; Drug Tolerance; Female; Humans; India; Male; Memory Disorders; Paranoid Disorders; Personality; Phytotherapy; Psychoses, Substance-Induced; Set, Psychology; Socioeconomic Factors; Substance-Related Disorders; United States