clozapine and Cognitive-Dysfunction

Schizophrenia is a severe neuropsychiatric disorder characterized by a diverse range of symptoms that can have profound impacts on the lives of patients. Currently available antipsychotics target dopamine receptors, and while they are useful for ameliorating the positive symptoms of the disorder, this approach often does not significantly improve negative and cognitive symptoms. Excitingly, preclinical and clinical research suggests that targeting specific muscarinic acetylcholine receptor subtypes could provide more comprehensive symptomatic relief with the potential to ameliorate numerous symptom domains. Mechanistic studies reveal that M1, M4, and M5 receptor subtypes can modulate the specific brain circuits and physiology that are disrupted in schizophrenia and are thought to underlie positive, negative, and cognitive symptoms. Novel therapeutic strategies for targeting these receptors are now advancing in clinical and preclinical development and expand upon the promise of these new treatment strategies to potentially provide more comprehensive relief than currently available antipsychotics.

Topics: Animals; Antipsychotic Agents; Clozapine; Cognitive Dysfunction; Humans; Muscarinic Agonists; Pyridines; Receptors, Muscarinic; Schizophrenia; Thiadiazoles

Clozapine is the first second generation antipsychotic with different receptor profile of action. Clozapine is the most efficacious drug for the treatment of psychotic disorder and is the drug of choice in treatment resistant schizophrenia. Clozapine is used in elderly patients infrequently owing to its adverse effects profile and tolerability. There is paucity of literature with respect to clozapine use in late life. In this narrative review, we discuss clozapine use in elderly and challenges associated with its use.

Topics: Aged; Aging; Agranulocytosis; Antipsychotic Agents; Cardiovascular Diseases; Clozapine; Cognitive Dysfunction; Humans; Metabolic Diseases; Schizophrenia; Seizures

Preclinical Research After the identification of the schizophrenia as an illness over a century ago, treatment of affected individuals included unspecific, mostly very robust methods including deep insulin coma and lobectomy/leucotomy. The first relatively specific treatment of schizophrenia started about 60 years ago with the antipsychotic chlorpromazine. All currently approved antipsychotic drugs block dopamine receptors, indicating that manipulation of dopaminergic function is fundamental to a therapeutic response in psychosis. Despite refinements in their mechanism of action, the therapeutic effects of subsequent generations of antipsychotics are insufficient in claiming superiority over the first generation, with the possible exception of clozapine. Dopamine receptor blockade is necessary but not always sufficient for antipsychotic response and improvements have been reported with molecules acting on other receptors (glutamate, glycine, cannabidiol, estrogen), intracellular signaling proteins, or products of identified risk genes. Here, we review the current status of drugs under investigation. In addition, we emphasize that the development of the novel compounds to target the underlying cognitive dysfunction and negative symptom dimension of full blown schizophrenia, or attenuated psychosis syndrome and specific endophenotypes related to the increased risk of psychosis in the general population, alongside efforts to deconstruct the concept of schizophrenia(s), represent the best way to meet patient needs for better therapies and more favorable outcomes. Drug Dev Res 77 : 357-367, 2016. © 2016 Wiley Periodicals, Inc.

Topics: Animals; Antipsychotic Agents; Chlorpromazine; Clozapine; Cognitive Dysfunction; Dopamine Antagonists; Drug Design; Humans; Schizophrenia

In a recent placebo-controlled, double-blind crossover trial (n = 52), significant beneficial effects on memory (d = 0.30) and negative symptoms (d = 0.29) were found after 12 weeks of memantine augmentation in patients with clozapine-refractory schizophrenia. In this open-label 1-year extension study we report the long-term effects and tolerability of memantine add-on therapy to clozapine.. Completers of the first trial who experienced beneficial effects during 12 weeks of memantine treatment received memantine for 1 year. Primary endpoints were memory and executive function using the Cambridge Neuropsychological Test Automated Battery, the Positive and Negative Syndrome Scale (PANSS), and the Clinical Global Impression Severity Scale (CGI-S).. Of 31 randomized controlled trial completers who experienced beneficial effects from memantine, 24 received memantine for 1 year. The small improvement in memory found in the memantine condition in the placebo-controlled trial remained stable in the extension study. Executive function did not improve. After 26 weeks of memantine add-on therapy to clozapine, PANSS negative symptoms (r = 0.53), PANSS positive symptoms (r = 0.50) and PANSS total symptoms (r = 0.54) significantly improved. Even further significant improvement in all these measures was observed between 26 weeks and 52 weeks of memantine, with effect sizes varying from 0.39 to 0.51. CGI-S showed a non-significant moderate improvement at 26 weeks (r = 0.36) and 52 weeks (r = 0.34). Memantine was well tolerated without serious adverse effects.. In the 1-year extension phase the favourable effect of adjunctive memantine on memory was sustained and we observed further improvement of negative, positive and overall symptoms in patients with clozapine-treated refractory schizophrenia.

Topics: Adult; Antipsychotic Agents; Clozapine; Cognitive Dysfunction; Drug Resistance; Drug Synergism; Drug Therapy, Combination; Excitatory Amino Acid Antagonists; Executive Function; Female; Follow-Up Studies; Humans; Male; Memantine; Memory Disorders; Middle Aged; Schizophrenia

Dysfunction of neuroplasticity due to N-methyl-d-aspartate (NMDA) receptor hypofunction may be a causal factor for memory and executive dysfunctioning in schizophrenia. Deregulation of NMDA transmission in the prefrontal cortex may also explain negative and positive symptoms. Clozapine augmentation with memantine targets altered NMDA receptor-mediated neurotransmission in schizophrenia and showed substantial beneficial effects on several symptom domains in a small proof-of-concept study. We evaluate effects of memantine add-on treatment to clozapine for memory and executive function, and negative and positive symptoms in schizophrenia.. Clozapine-treated patients with refractory schizophrenia were randomly assigned to 12 weeks of double-blind adjunctive treatment with memantine (n = 26) or placebo (n = 26). Crossover occurred after a 2-week placebo wash-out period. Primary endpoints were change from baseline to 12 weeks treatment and 14 weeks to 26 weeks treatment on memory and executive function using the Cambridge Neuropsychological Test Automated Battery (CANTAB), Positive and Negative Syndrome Scale (PANSS), and Clinical Global Impression Severity Scale (CGI-S). Side effects were assessed using the Liverpool University Neuroleptic Side-Effect Rating Scale.. When compared with placebo, memantine improved a composite memory score comprising verbal recognition memory and paired associates learning task scores on the CANTAB (effect size = 0.30) and PANSS negative subscale score (effect size = 0.29). Side effects were mild and transient.. In patients with clozapine-treated refractory schizophrenia, memantine addition significantly improved verbal and visual memory and negative symptoms without serious adverse effects. These results justify further investigations on long-term memantine augmentation to clozapine in treatment-resistant schizophrenia.

Topics: Adult; Antipsychotic Agents; Clozapine; Cognitive Dysfunction; Cross-Over Studies; Double-Blind Method; Drug Resistance; Drug Therapy, Combination; Excitatory Amino Acid Antagonists; Female; Humans; Male; Memantine; Memory Disorders; Middle Aged; Outcome Assessment, Health Care; Schizophrenia

The deficiency of the gaseous molecule nitric oxide (NO) seems to be critically involved in the pathogenesis of schizophrenia. Thus, molecules that can normalize NO levels, as are NO donors, might be of utility for the medication of this psychiatric disease. The aim of the present study was to detect the ability of the NO donor molsidomine to reduce schizophrenia-like impairments produced by the blockade of the N-methyl-D-aspartate (NMDA) receptor in rats. Molsidomine's ability to attenuate social withdrawal and spatial recognition memory deficits induced by the NMDA receptor antagonist ketamine were assessed using the social interaction and the object location test, respectively. Further, the efficacy of the combination of sub-effective doses of molsidomine with sub-effective doses of the atypical antipsychotic clozapine in alleviating non-spatial recognition memory deficits was evaluated utilizing the object recognition task. Molsidomine (2 and 4 mg/kg) attenuated social withdrawal and spatial recognition memory deficits induced by ketamine. Co-administration of inactive doses of molsidomine (1 mg/kg) and clozapine (0.1 mg/kg) counteracted delay-dependent and ketamine-induced non-spatial recognition memory deficits. The current findings suggest that molsidomine is sensitive to glutamate hypofunction since it attenuated behavioral impairments in animal models mimicking the negative symptoms and cognitive deficits of schizophrenia. Additionally, the present results support the potential of molsidomine as an adjunctive drug for the therapy of schizophrenia.

Topics: Animals; Clozapine; Cognition; Cognitive Dysfunction; Ketamine; Memory Disorders; Molsidomine; Nitric Oxide; Nitric Oxide Donors; Rats; Rats, Wistar; Receptors, N-Methyl-D-Aspartate; Social Isolation

Schizophrenia (SCZ) is a severe psychiatric disorder characterized by positive symptoms, negative symptoms, and cognitive deficits. Current antipsychotic treatment in SCZ improves positive symptoms but has major side effects and little impact on negative symptoms and cognitive impairment. The pathoetiology of SCZ remains unclear, but is known to involve small GTPase signaling. Rho kinase, an effector of small GTPase Rho, is highly expressed in the brain and plays a major role in neurite elongation and neuronal architecture. This study used a touchscreen-based visual discrimination (VD) task to investigate the effects of Rho kinase inhibitors on cognitive impairment in a methamphetamine (METH)-treated male mouse model of SCZ. Systemic injection of the Rho kinase inhibitor fasudil dose-dependently ameliorated METH-induced VD impairment. Fasudil also significantly suppressed the increase in the number of c-Fos-positive cells in the infralimbic medial prefrontal cortex (infralimbic mPFC) and dorsomedial striatum (DMS) following METH treatment. Bilateral microinjections of Y-27632, another Rho kinase inhibitor, into the infralimbic mPFC or DMS significantly ameliorated METH-induced VD impairment. Two proteins downstream of Rho kinase, myosin phosphatase-targeting subunit 1 (MYPT1; Thr696) and myosin light chain kinase 2 (MLC2; Thr18/Ser19), exhibited increased phosphorylation in the infralimbic mPFC and DMS, respectively, after METH treatment, and fasudil inhibited these increases. Oral administration of haloperidol and fasudil ameliorated METH-induced VD impairment, while clozapine had little effect. Oral administration of haloperidol and clozapine suppressed METH-induced hyperactivity, but fasudil had no effect. These results suggest that METH activates Rho kinase in the infralimbic mPFC and DMS, which leads to cognitive impairment in male mice. Rho kinase inhibitors ameliorate METH-induced cognitive impairment, perhaps via the cortico-striatal circuit.

Topics: Animals; Clozapine; Cognitive Dysfunction; Haloperidol; Male; Methamphetamine; Mice; Monomeric GTP-Binding Proteins; Protein Kinase Inhibitors; rho-Associated Kinases; Schizophrenia

Orexin-A and brain-derived neurotrophic factor (BDNF) are implicated in regulating metabolic syndrome (MetS) and cognitive impairment of schizophrenia. However, the associations among them remains unclear. Here, we aimed to investigate the relationship between Orexin-A levels, BDNF, MetS, clinical symptom profile, and cognitive function in schizophrenia patients following long-term clozapine treatment. We measured Orexin-A and BDNF levels in 140 schizophrenia patients with and without MetS. We assessed clinical symptoms on the Positive and Negative Syndrome Scale and cognitive function by the assessment of Neuropsychological Status (RBANS), and examined their associations with Orexin-A. Patients with MetS had significantly lower Orexin-A levels and higher coding test, attention span and delayed retention in RBANS (P < 0.05). Correlation analysis showed that Orexin-A was associated with BDNF, TG, HDLC, PANSS active social avoidance and emotional withdrawal significantly. Besides, Orexin-A significantly interacted with BDNF for metabolic and cognitive profiles including waist circumference, delayed retention and list recognition. Logistic regression analysis showed that Orexin-A level (odds ratio [OR] = 0.380, 95% confidence interval [CI]: 0.151-0.952, P = 0.039) and total illness duration (OR = 0.932, 95% CI: 0.875-0.991, P = 0.025) were predictive variables of MetS. However, there was no significant relationship between Orexin-A and cognitive function after adjustment for age, sex and educational levels. Totally, a lower plasma Orexin-A level seems to be related to metabolic parameters more than cognitive profiles. The interaction of Orexin-A with BDNF may be partly responsible for worse MetS and better cognition of elderly schizophrenia, but the causal relationship needs further clarification.

Topics: Aged; Brain-Derived Neurotrophic Factor; Clozapine; Cognitive Dysfunction; Humans; Metabolic Syndrome; Orexins; Schizophrenia

Cognitive dysfunction is a core feature of schizophrenia that strongly correlates to the patients' difficulties in independent living and occupational functioning. Synaptic dysfunction may result in cognitive and behavioral changes similar to what have been identified in schizophrenia. Shi-Zhen-An-Shen Decoction (SZASD) is the empirical formula of traditional Chinese medicine adopted in treating psychiatric symptoms, especially the cognitive impairment in schizophrenia patients, with proven efficacy in the long term of clinical practice in Beijing Anding Hospital, Capital Medical University. However, the mechanisms of SZASD on the cognitive improvement in schizophrenia is still unclear. Here, we aim to investigate the underlying mechanisms of the impact of SZASD on the cognitive impairment in MK801-induced schizophrenia-like rats.. Six rat groups (n = 12 per group) were subjected to different treatments for 14 days. All the six groups were injected intraperitoneally with a given volume of 0.9% saline and MK801 (0.2 mg/kg) for consecutive 14 days for modelling. And the rats in the SZASD-treated groups and the clozapine-treated group were given SZASD (low, middle, and high doses) or clozapine, respectively, by intragastric administration. Then, we performed behavioral tests after the treatments, and the rats were sacrificed on the 19th day for biological analysis.. Behavioral tests indicated that SZASD mitigated the aberrant motor activity and improved schizophrenia-like rats' spatial reference memory and sensory gating ability. Furthermore, SZASD significantly increased the expressions of PSD95, BDNF, and synapsin I in the hippocampus of MK801-induced schizophrenia-like rats.. Our findings suggest that SZASD may ameliorate cognitive impairment by restoring the levels of synaptic proteins in the hippocampus.

Topics: Animals; Clozapine; Cognitive Dysfunction; Disease Models, Animal; Dizocilpine Maleate; Rats; Schizophrenia

Engineered G protein-coupled receptors (GPCRs) are commonly used in chemogenetics as designer receptors exclusively activated by designer drugs (DREADDs). Although several GPCRs have been studied in astrocytes using a chemogenetic approach, the functional role of the astrocytic G

Topics: Animals; Astrocytes; Brain; Clozapine; Cognitive Dysfunction; Cytokines; Designer Drugs; Disease Models, Animal; GTP-Binding Protein alpha Subunits, Gi-Go; Hippocampus; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Molecular Targeted Therapy; Neuroinflammatory Diseases; Nitric Oxide; Nitric Oxide Synthase Type II; Receptors, G-Protein-Coupled

Cognitive disorders associated with schizophrenia are closely linked to prefrontal cortex (PFC) dysfunction. Administration of the non-competitive NMDA receptor antagonist ketamine (KET) induces cognitive impairment in animals, producing effects similar to those observed in schizophrenic patients. In a previous study, we showed that KET (20 mg/kg) induces cognitive deficits in mice and that administration of clozapine (CLZ) reverses this effect. To identify biochemical mechanisms related to CLZ actions in the context of KET-induced impairment, we performed a biochemical analysis using the same experimental paradigm-acute and sub-chronic administration of these drugs (0.3 and 1 mg/kg).. Since the effect of CLZ mainly depends on G-protein-related receptors, we used the Signaling PathwayFinder Kit to identify 84 genes involved in GPCR-related signal transduction and then verified the genes that were statistically significantly different on a larger group of mice using RT-PCR and Western blot analyses after the administration of acute and sub-chronic drugs.. The screening kit we used to study the expression of GPCR-related signal transduction allowed us to select several important genes affected by CLZ. However, the obtained data do not explain the mechanism of action of CLZ that is responsible for reversing KET-induced cognitive impairment.

Topics: Animals; Biomarkers; Clozapine; Cognitive Dysfunction; Gene Expression Profiling; Gene Expression Regulation; Ketamine; Male; Mice; Receptors, G-Protein-Coupled

Clozapine has remarkable efficacy on both negative and cognitive symptoms of schizophrenia due to its slight activation of NMDA receptor. In fact, much evidence to the contrary. NMDAR is a complex containing specific binding sites, which are regulated to improve negative symptoms and cognitive deficits associated with individuals affected by schizophrenia. PQQ is a powerful neuroprotectant that specifically binds with NMDA receptors in the brain to produce beneficial physiological and cognitive outcomes. The aim of this study was to enhance NMDAR function and improve cognitive ability in schizophrenia by PQQ combined with clozapine.. Rats were divided into four groups (n = 5) including control (saline), model (MK-801, 0.5 mg·kg. Results indicated that clozapine and PQQ combination therapy can improve MK801-induced schizophrenia behavior including stereotyped behavior, locomotor hyperactivity and cognitive impairment. Furthermore, we found that modulating NMDA receptors could ameliorate the memory impairments in Mk-801 induced schizophrenia rats by reducing the expression of NMDAR1 and MGLUR3, decreasing hippocampal tau hyperphosphorylation and inhibiting apoptosis through Akt /GSK-3β signaling pathway.. These findings suggest that combination therapy for enhancing NMDA receptors may be able to rescue cognition deficit in schizophrenia. More studies are needed to better elucidate these mechanisms.

Topics: Animals; Antipsychotic Agents; Clozapine; Cognition; Cognitive Dysfunction; Dizocilpine Maleate; Glycogen Synthase Kinase 3 beta; Humans; Rats; Receptors, N-Methyl-D-Aspartate; Schizophrenia

Despite its benefits, a major concern regarding antipsychotic treatment is its possible impact on the brain's structure and function. This study sought to explore the characteristics of white matter structural networks in chronic never-treated schizophrenia and those treated with clozapine or risperidone, and its potential association with cognitive function.. Diffusion tensor imaging was performed on a unique sample of 34 schizophrenia patients treated with antipsychotic monotherapy for over 5 years (17 treated with clozapine and 17 treated with risperidone), 17 never-treated schizophrenia patients with illness duration over 5 years, and 27 healthy control participants. Graph theory and network-based statistic approaches were employed.. We observed a disrupted organization of white matter structural networks as well as decreased nodal and connectivity characteristics across the schizophrenia groups, mainly involving thalamus, prefrontal, and occipital regions. Alterations in nodal and connectivity characteristics were relatively milder in risperidone-treated patients than clozapine-treated patients and never-treated patients. Altered global network measures were significantly associated with cognitive performance levels. Structural connectivity as reflected by network-based statistic mediated the difference in cognitive performance levels between clozapine-treated and risperidone-treated patients.. These results are constrained by the lack of random assignment to different types of antipsychotic treatment.. These findings provide insight into the white matter structural network deficits in patients with chronic schizophrenia, either being treated or untreated, and suggest white matter structural networks supporting cognitive function may benefit from antipsychotic treatment, especially in those treated with risperidone.

Topics: Adult; Antipsychotic Agents; Chronic Disease; Clozapine; Cognitive Dysfunction; Diffusion Tensor Imaging; Female; Humans; Male; Middle Aged; Nerve Net; Risperidone; Schizophrenia; Treatment Outcome; White Matter

A new strategy in the design of aminergic GPCR ligands is proposed - the use of aromatic, heterocyclic basic moieties in place of the evergreen piperazine or alicyclic and aliphatic amines. This hypothesis has been tested using a benchmark series of 5-HT

Topics: Animals; Cells, Cultured; Cognitive Dysfunction; Dose-Response Relationship, Drug; Drug Design; HEK293 Cells; Hep G2 Cells; Humans; Imidazoles; Male; Models, Molecular; Molecular Structure; Rats; Rats, Sprague-Dawley; Receptors, Serotonin; Scopolamine; Serotonin Antagonists; Structure-Activity Relationship

Topics: Adult; Antipsychotic Agents; Clozapine; Cognition; Cognitive Dysfunction; Humans; Schizophrenia; Schizophrenic Psychology

We previously reported that centrally acting non-narcotic antitussives, including tipepidine, inhibit G-protein-coupled inwardly rectifying potassium (GIRK) channel-activated currents of neurons. In addition, when administered at a cough suppressant dose, the drugs ameliorated the symptoms of various models of intractable brain disease in rodents. In the current study, we investigated whether tipepidine causes recovery from schizophrenia-like cognitive dysfunction, which was induced by MK-801 (0.2 mg/kg, i.p.) in mice. We also examined the effect of tipepidine and clozapine co-administration on the dysfunction. Moreover, we studied whether clozapine inhibits GIRK channel activated currents in single brain neurons using the patch-clamp technique. Tipepidine elicited recovery from MK-801-induced cognitive impairment in the novel objective recognition test and Y-maze test. Further, co-administration of tipepidine and clozapine, at subthreshold doses of each drug, improved MK-801-induced cognitive impairment in the novel objective recognition test. Clozapine (3 × 10

Topics: Animals; Antidepressive Agents; Antitussive Agents; Clozapine; Cognitive Dysfunction; Disease Models, Animal; Dizocilpine Maleate; Dopaminergic Neurons; G Protein-Coupled Inwardly-Rectifying Potassium Channels; Male; Mice; Patch-Clamp Techniques; Piperidines; Rats; Rats, Wistar; Schizophrenia; Ventral Tegmental Area

Topics: Adult; Antipsychotic Agents; Clozapine; Cognitive Dysfunction; Humans; Male; Schizophrenia

The primary aim was to comprehensively describe the characteristics of a cohort of older people taking clozapine.. Participants aged ⩾ 60 had a geriatric assessment including full medical, medication and social history. Standardized screening tools for cognition, function, comorbidity and antipsychotic side effects were administered and descriptive statistics utilized.. Thirteen patients were eligible to participate and 10 were assessed. The mean age was 69 years. The mean clozapine dose was 309 mg/day and mean duration of use was 10 years. All participants had executive dysfunction, and half had cognitive impairment. The mean number of co-morbid conditions was five. Seven people met the criteria for polypharmacy. Eight people experienced moderate-severe antipsychotic-related side-effects. The majority demonstrated impaired physical functioning.. This cohort of older people taking clozapine experienced considerable morbidity, functional and cognitive impairment. We suggest routine screening of cognition and function in clozapine patients aged ⩾ 60 years. Those screening positive should be considered for further assessment by Older Person's Mental Health Services and/or a Geriatric Medicine service.

Topics: Aged; Aged, 80 and over; Aging; Antipsychotic Agents; Clozapine; Cognitive Dysfunction; Comorbidity; Cross-Sectional Studies; Executive Function; Female; Humans; Male; Middle Aged; New South Wales; Pilot Projects; Schizophrenia

Several atypical antipsychotic drugs (APDs) have high affinity for the dopamine (DA) D

Topics: Animals; Antipsychotic Agents; Benzamides; Clozapine; Cognitive Dysfunction; Female; Lurasidone Hydrochloride; Phencyclidine; Piperazines; Pyridines; Pyrroles; Rats; Rats, Long-Evans; Receptor, Serotonin, 5-HT1A; Receptors, Dopamine D4; Schizophrenia; Serotonin 5-HT1 Receptor Agonists

Enhancement of cholinergic function via muscarinic acetylcholine receptor M

Topics: Animals; Antipsychotic Agents; Benzoxazines; Clozapine; Cognitive Dysfunction; Drug Interactions; Female; Lurasidone Hydrochloride; Phencyclidine; Rats; Receptor, Muscarinic M1; Recognition, Psychology; Scopolamine; Signal Transduction; Sulfonamides; Thiadiazoles

Hypothetically, psychotic disorders could be caused or conditioned by immunological mechanisms. If so, one might expect there to be peripheral immune system phenotypes that are measurable in blood cells as biomarkers of psychotic states.. We used multi-parameter flow cytometry of venous blood to quantify and determine the activation state of 73 immune cell subsets for 18 patients with chronic schizophrenia (17 treated with clozapine), and 18 healthy volunteers matched for age, sex, BMI and smoking. We used multivariate methods (partial least squares) to reduce dimensionality and define populations of differentially co-expressed cell counts in the cases compared to controls.. Schizophrenia cases had increased relative numbers of NK cells, naïve B cells, CXCR5+ memory T cells and classical monocytes; and decreased numbers of dendritic cells (DC), HLA-DR+ regulatory T-cells (Tregs), and CD4+ memory T cells. Likewise, within the patient group, more severe negative and cognitive symptoms were associated with decreased relative numbers of dendritic cells, HLA-DR+ Tregs, and CD4+ memory T cells. Motivated by the importance of central nervous system dopamine signalling for psychosis, we measured dopamine receptor gene expression in separated CD4+ cells. Expression of the dopamine D3 (DRD3) receptor was significantly increased in clozapine-treated schizophrenia and covaried significantly with differentiated T cell classes in the CD4+ lineage.. Peripheral immune cell populations and dopaminergic signalling are disrupted in clozapine-treated schizophrenia. Immuno-phenotypes may provide peripherally accessible and mechanistically specific biomarkers of residual cognitive and negative symptoms in this treatment-resistant subgroup of patients.

Topics: Adult; Antipsychotic Agents; Biomarkers; Case-Control Studies; CD4 Lymphocyte Count; Clozapine; Cognitive Dysfunction; Cross-Sectional Studies; Dendritic Cells; Female; Flow Cytometry; HLA-DR Antigens; Humans; Immunologic Memory; Killer Cells, Natural; Lymphocyte Activation; Male; Middle Aged; Receptors, Dopamine D3; Schizophrenia; T-Lymphocyte Subsets; T-Lymphocytes, Regulatory; Young Adult

Capgras delusion is a delusional misidentification syndrome, in which the patient is convinced that someone that is well known to them, usually a close relative, has been replaced by an impostor or double. Although it has been frequently described in psychotic syndromes, including paranoid schizophrenia, over a third of the documented cases of Capgras delusion are observed in patients with organic brain lesions or neurodegenerative disease, including Parkinson's Disease. Variants of Capgras involving animals or inanimate objects have also been described. The etiology of Capgras in Parkinson's remains unclear, but may arise from a combination of factors, such as frontal lobe dysfunction and dopaminergic medication.. We present the case of a 53-year old right-handed female with Parkinson's disease who developed Capgras delusion during treatment with dopamine agonists and Levodopa/Carbidopa. She became convinced that her pet dogs and the plants in her garden had been substituted by identically looking ones. Our patient was initially treated with Quetiapine, with no improvement, and subsequently treated with Clozapine, which lead to partial regression of her symptoms. Neuropsychological Evaluation showed Mild Cognitive Impairment in Executive Functions.. Given the clinical history, onset and evolution of symptoms we believe our patient's delusion resulted from the overlap of dopaminergic medication and Mild Cognitive Impairment in executive functions. Zoocentric Capgras, the variant we describe, has been rarely described in scientific literature, and we believe it is of interest due to its unusual characteristics.

Topics: Animals; Antiparkinson Agents; Antipsychotic Agents; Capgras Syndrome; Carbidopa; Clozapine; Cognitive Dysfunction; Delusions; Dibenzothiazepines; Dogs; Dopamine Agonists; Drug Therapy, Combination; Female; Humans; Levodopa; Parkinson Disease; Pets; Plants; Quetiapine Fumarate