humulene and Atrophy

There is convincing evidence that schizophrenia is characterised by progressive brain volume changes during the course of the illness. In a large longitudinal study it was shown that different age-related trajectories of brain tissue loss are present in patients compared to healthy subjects, suggesting that brain maturation that occurs in the third and fourth decade of life is abnormal in schizophrenia. However, studies show that medication intake and cannabis use are important confounding factors when interpreting brain volume (change) abnormalities. Indeed, continues use of cannabis, but not cigarette smoking, is associated to a more pronounced loss of grey matter in the anterior cingulated and the prefrontal cortex. Atypical antipsychotics have been found to be related to smaller decreases in tissue loss. Moreover, independent of antipsychotic medication intake, the brain volume abnormalities appear associated to the outcome of the illness.

Topics: Antipsychotic Agents; Atrophy; Brain; Cannabis; Disease Progression; Gyrus Cinguli; Humans; Nerve Fibers, Unmyelinated; Prefrontal Cortex; Prognosis; Schizophrenia; Smoking

Cannabis is the most widely used illicit drug. Despite this, only a small number of studies have investigated the long-term neurotoxic consequences of cannabis use. Structural and functional neuroimaging techniques are powerful research tools to investigate possible cannabis-induced pathophysiological changes. A computer literature review was conducted in the MEDLINE and PsycLIT databases between 1966 and November of 2004 with the search terms 'cannabis', 'marijuana', 'neuroimaging', 'magnetic resonance', 'computed tomography', 'positron emission tomography', 'single photon emission computed tomography", 'SPET', 'MRI' and 'CT'. Structural neuroimaging studies have yielded conflicting results. Most studies report no evidence of cerebral atrophy or regional changes in tissue volumes, and one study suggested that long-term users who started regular use on early adolescence have cerebral atrophy as well as reduction in gray matter. However, several methodological shortcomings limit the interpretation of these results. Functional neuroimaging studies have reported increases in neural activity in regions that may be related with cannabis intoxication or mood-change effects (orbital and mesial frontal lobes, insula, and anterior cingulate) and decreases in activity of regions related with cognitive functions impaired during acute intoxication. The important question whether residual neurotoxic effects occur after prolonged and regular use of cannabis remains unclear, with no study addressing this question directly. Better designed neuroimaging studies, combined with cognitive evaluation, may be elucidative on this issue.

Topics: Atrophy; Brain; Cannabis; Humans; Magnetic Resonance Imaging; Mental Disorders; Tomography, Emission-Computed

This paper examines the research evidence relating sustained use of marijuana to chronic cerebral impairment. Evidence from both American and cross-cultural studies is reviewed, with a particular emphasis on methodological problems in the research. The focus of this paper is on neurological findings while another paper focuses on neuropsychological findings. On the basis of available research, it was concluded that there is no evidence that marijuana produces gross structural cerebral changes and little evidence that it leads to functional impairment, although subtle impairment cannot be ruled out.

Topics: Atrophy; Brain; Cannabis; Cross-Cultural Comparison; Dronabinol; Electroencephalography; Humans; Marijuana Abuse; Mental Disorders; Mental Status Schedule; Neuropsychological Tests; Radiography; Research Design; Substance-Related Disorders; United States

Topics: Atrophy; Barbiturates; Brain; Cannabis; Dose-Response Relationship, Drug; Efficiency; Hallucinogens; Humans; Immunity, Cellular; Methadone; Methamphetamine; Narcotic Antagonists; Opium; Substance-Related Disorders; Therapeutic Community; United States

Sub-Saharan Africa is one of the top three regions with the highest rates of opioid-related premature mortality. Nyaope is the street name for what is believed to be a drug cocktail in South Africa although recent research suggests that it is predominantly heroin. Nyaope powder is most commonly smoked together with cannabis, a drug-use pattern unique to the region. Due to the increasing burden of this drug in low-income communities and the absence of human structural neuroimaging data of combination heroin and cannabis use disorder, we initiated an important cohort study in order to identify neuroanatomical sequelae. Twenty-eight male nyaope users and thirty healthy, matched controls were recruited from drug rehabilitation centers and the community, respectively. T1-weighted MRI images were obtained using a 3 T General Electric Discovery and cortical thickness was examined and compared. Nyaope users displayed extensive grey matter atrophy in the right hemispheric medial orbitofrontal, rostral middle frontal, superior temporal, superior frontal, and supramarginal gyri (two-sided t-test, p < 0.05, corrected for multiple comparisons). Our findings indicate cortical abnormality in nyaope users in regions involved in impulse control, decision making, social- and self-perception, and working memory. Importantly, affected brain regions show large overlap with the pattern of cortical abnormalities shown in heroin use disorder.

Topics: Adult; Atrophy; Cannabis; Case-Control Studies; Cerebral Cortex; Cohort Studies; Gray Matter; Heroin; Heroin Dependence; Humans; Illicit Drugs; Magnetic Resonance Imaging; Male; Marijuana Abuse; Neuroimaging; South Africa

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

Computed tomographic changes compatible with cerebral atrophy have been observed clinically and in experimental drug abuse animals. Most of the patients were thought to be polydrug users, but amphetamines and alcohol were two of the more commonly misused drugs. In the experimental animals, the effects of amphetamine, secobarbital, and marijuana were studied. Brain damage was present in the animals that received intravenous amphetamine.

Topics: Administration, Oral; Adolescent; Adult; Animals; Atrophy; Brain; Cannabis; Cerebral Ventricles; Dilatation, Pathologic; Haplorhini; Humans; Injections, Intravenous; Macaca mulatta; Male; Methamphetamine; Secobarbital; Substance-Related Disorders; Tomography, X-Ray Computed

Computerized transaxial tomography (CTT) studies of 12 young men having histories of heavy cannabis smoking revealed no evidence of cerebral atrophy.

Topics: Adult; Age Factors; Atrophy; Brain; Brain Diseases; Cannabis; Humans; Male; Substance-Related Disorders; Tomography, X-Ray Computed

Computed tomographic scans were obtained from 19 men with long histories of heavy marijuana smoking and who were also observed to smoke large amounts of marijuana under research ward conditions. The ventricular system and subarachnoid spaces were normal in size and showed no indication of atrophic change.

Topics: Adult; Age Factors; Amphetamines; Atrophy; Barbiturates; Brain; Brain Diseases; Cannabis; Humans; Male; Sex Factors; Substance-Related Disorders; Tomography, X-Ray Computed

Topics: Administration, Oral; Anemia; Animals; Atrophy; Behavior, Animal; Bone Marrow; Cannabis; Colitis, Ulcerative; Depression, Chemical; Dronabinol; Drug Tolerance; Haplorhini; Hyperplasia; Injections, Intravenous; Kidney Diseases; Macaca; Pancreas; Time Factors; Water-Electrolyte Balance

Topics: Adolescent; Adult; Atrophy; Brain Diseases; Cannabis; Dementia; Female; Humans; Male; Substance-Related Disorders

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

Topics: Abnormalities, Drug-Induced; Administration, Oral; Animals; Atrophy; Brain; Cannabis; Cardiovascular System; Dose-Response Relationship, Drug; Dronabinol; Drug Interactions; Female; Humans; Injections, Intraperitoneal; Injections, Subcutaneous; Liver; Lung; Male; Pregnancy; Psychoses, Substance-Induced; Rabbits; Rats; Substance Withdrawal Syndrome; Substance-Related Disorders

Topics: Adolescent; Adult; Atrophy; Brain; Brain Diseases; Cannabis; Electroencephalography; Humans; Pneumoencephalography; Substance-Related Disorders

Topics: Atrophy; Brain Diseases; Cannabis; Humans; Substance-Related Disorders

Topics: Adult; Aged; Atrophy; Brain; Brain Diseases; Cannabis; Cerebral Ventriculography; Humans; Male; Middle Aged; Substance-Related Disorders

Topics: Adolescent; Adult; Atrophy; Brain Diseases; Cannabis; Humans