Update on typical and atypical antipsychotic drugs

Membrane Permeability Monitoring to Antipsychotic Olanzapine Using Platinum Black-Modified Electrodes

The blood-brain barrier (BBB) is key to the regular functioning of the central nervous system. The dysfunction of the BBB has been described in various neurological disorders, including schizophrenia. Schizophrenia (SCZ) is a chronic psychiatric disorder described by hallucinations, delusions, and negative symptoms. The Olanzapine (OLZ) drug is an electroactive species, and its levels can be monitored using electrochemical sensors. The detection of OLZ was demonstrated previously by using electrochemical sensors, and this technique can be used to monitor the levels of OLZ in real time. The challenge is to identify the permeability of OLZ through the BBB, so a replica model was designed with the BBB based on a Transwell membrane seeded with endothelial cells. A microfabricated electrode consisting of a 3 mm Au disk was modified with platinum black; this enables higher selectivity of electrochemical signals from OLZ. The dose-response of OLZ was characterized in phosphate buffer saline solution (10 mM, pH 7.4) by adding 20-200 nM (in steps 20) of OLZ stock solution. The observed chronoamperometric electrochemical signals showed an increasing current at 0.45 V vs. Ag/AgCl with an increasing OLZ concentration. The controls for the experiments were performed in phosphate-buffered saline solution (10 mM, pH 7.4). The detection limit was calculated as 9.96 ± 7.35 × 10-6 nM from the calibration curve. The membrane permeability of the OLZ drug tested with five SCZ patients was monitored by studying the TEER measurements and permeability rate constant data.

A molecular mechanism mediating clozapine-enhanced sensorimotor gating

The atypical antipsychotic clozapine targets multiple receptor systems beyond the dopaminergic pathway and influences prepulse inhibition (PPI), a critical translational measure of sensorimotor gating. Since PPI is modulated by atypical antipsychotics such as risperidone and clozapine, we hypothesized that p11-an adaptor protein associated with anxiety- and depressive-like behaviors and G-protein-coupled receptor function-might modulate these effects. In this study, we assessed the role of p11 in clozapine's PPI-enhancing effect by testing wild-type and global p11 knockout (KO) mice in response to haloperidol, risperidone, and clozapine. We also performed structural and functional brain imaging. Contrary to our expectation that anxiety-like p11-KO mice would exhibit an augmented startle response and heightened sensitivity to clozapine, PPI tests showed that p11-KO mice were unresponsive to the PPI-enhancing effects of risperidone and clozapine. Imaging revealed distinct regional brain volume differences and reduced hippocampal connectivity in p11-KO mice, with significantly blunted clozapine-induced connectivity changes in the CA1 region. Our findings highlight a novel role for p11 in modulating clozapine's effects on sensorimotor gating and hippocampal connectivity, offering new insight into its functional pathways.

Influence of antipsychotic drugs on microglia-mediated neuroinflammation in schizophrenia: perspectives in an astrocyte-microglia co-culture model

Schizophrenia is a severe mental disorder with a strong lifetime impact on patients' health and wellbeing. Usually, symptomatic treatment includes typical or atypical antipsychotics. Study findings show an involvement of low-grade inflammation (blood, brain parenchyma, and cerebrospinal fluid) in schizophrenia. Moreover, experimental and neuropathological evidence suggests that reactive microglia, which are the main resident immune cells of the central nervous system (CNS), have a negative impact on the differentiation and function of oligodendrocytes, glial progenitor cells, and astrocytes, which results in the disruption of neuronal networks and dysregulated synaptic transmission, contributing to the pathophysiology of schizophrenia. Here, the role of microglial cells related to neuroinflammation in schizophrenia was discussed to be essential. This review aims to summarize the evidence for the influence of antipsychotics on microglial inflammatory mechanisms in schizophrenia. Furthermore, we propose an established astrocyte-microglia co-culture model for testing regulatory mechanisms and examining the effects of antipsychotics on glia-mediated neuroinflammation. This could lead to a better understanding of how typical and atypical antipsychotics can be used to address positive and negative symptoms in schizophrenia and comorbidities like inflammatory diseases or the status of low-grade inflammation.

Antipsychotic Polypharmacy for Treatment Resistant Schizoaffective Disorder: A Case Report

This case presents a male in his early 20s with schizoaffective disorder and cannabis use disorder presenting with treatment resistance demonstrated by inadequate control of psychotic symptoms despite multiple trials of antipsychotics. The patient was experiencing positive symptoms, including hyper-religiosity, hallucinations, mood lability, agitation, and aggression. The patient and next of kin were unable to provide consent for clozapine due to concerns for monitoring requirements. The patient continued paliperidone long-acting injectable (LAI) 234 milligrams (mg) every four weeks and divalproex 750 mg twice per day (BID) and was started on haloperidol with titration to 2 mg BID. Following the addition of a second antipsychotic agent, the patient exhibited marked improvement with reduced intensity of perceptual disturbances. This case underscores the potential benefits and challenges of antipsychotic polypharmacy in addressing residual psychosis and improving functional outcomes. We also provide an overview of available evidence for and against antipsychotic polypharmacy, defined as two or more antipsychotic medications used in a patient concurrently, as well as alternative non-antipsychotic agents for treatment-resistant schizophrenia.

OBF-Psychiatric, a motor activity dataset of patients diagnosed with major depression, schizophrenia, and ADHD

Mental health is vital to human well-being, and prevention strategies to address mental illness have a significant impact on the burden of disease and quality of life. With the recent developments in body-worn sensors, it is now possible to continuously collect data that can be used to gain insights into mental health states. This has the potential to optimize psychiatric assessment, thereby improving patient experiences and quality of life. However, access to high-quality medical data for research purposes is limited, especially regarding diagnosed psychiatric patients. To this extent, we present the OBF-Psychiatric dataset which comprises motor activity recordings of patients with bipolar and unipolar major depression, schizophrenia, and ADHD (attention deficit hyperactivity disorder). The dataset also contains data from a clinical sample diagnosed with various mood and anxiety disorders, as well as a healthy control group, making it suitable for building machine learning models and other analytical tools. It contains recordings from 162 individuals totalling 1565 days worth of motor activity data with a mean of 9.6 days per individual.

Response to clozapine and its predictors in treatment-resistant schizophrenia spectrum disorders: A retrospective chart review

The response rate to clozapine in patients with treatment-resistant schizophrenia spectrum disorders (TRSS) is around 40 %. But, in general, a better prognosis is noted for schizophrenia in developing countries, including India. Given the scarcity of related literature from India, this study aimed to evaluate the response rates to clozapine in TRSS and explore predictors of response. Sociodemographic and clinical information from randomly selected 250 patients on clozapine for TRSS was collected through a retrospective chart review. Clozapine response was determined using the Clinical Global Impression-Schizophrenia scale at 6, 12, 24 weeks, and one year of initiating clozapine. Elastic net logistic regression analysis was performed to identify predictors of clozapine response. A total of 54 % responded to clozapine, with much or very much improvement in positive and overall symptoms of schizophrenia by the end of 12 weeks of clozapine initiation. Among all the responders at 12 weeks, 94 % continued to maintain response at one-year follow-up, and among non-responders, 34.2 % showed clinical improvement by 1-year follow-up. Lower symptom severity at baseline, good response to clozapine at six weeks, history of more suicidal attempts, and few other clinical symptoms like delusions and sociodemographic factors predicted a response to clozapine. A higher response rate (54 %) to clozapine is noted in 3rd month of clozapine, contrasting with the existing literature. Persistence of treatment could elicit further response over a year in early non-responders. Our study findings revealed that the demographic profile and clinical determinants may have an effect on clozapine response.

Alterations in regional homogeneity in schizophrenia patients comorbid with metabolic syndrome treated with risperidone or clozapine

The neuroimaging mechanisms that arise in patients with schizophrenia and comorbid metabolic syndrome (MetS) remain poorly understood. This study was devised to examine potential alterations in regional homogeneity (ReHo) that arise in schizophrenia patients with comorbid MetS undergoing risperidone or clozapine treatment. In total, 43 schizophrenia patients undergoing risperidone or clozapine treatment were enrolled in this study, of whom 20 had comorbid MetS (SZ-MetS) while 23 did not (SZ-nMetS). In addition, 28 sex- and age-matched healthy controls (HCs) were analyzed. Analyses of covariance (ANCOVA) were used to compare ReHo in this study, utilizing age, sex, and years of education as covariates, with subsequent post hoc testing. Correlations between brain regions showing differences between groups of patients with schizophrenia and MetS-related indicators were also assessed. Relative to HCs, patients in both the SZ-MetS and SZ-nMetS groups exhibited reductions in ReHo in the right postcentral gyrus, left superior parietal gyrus, and left middle occipital gyrus. A decrease in ReHo was also evident in the left calcarine fissure and surrounding cortex and the right angular gyrus of patients in the SZ-MetS group, while the SZ-nMetS group exhibited reductions in ReHo in the left superior occipital gyrus and the right precuneus, together with an increase in ReHo in the right inferior orbitofrontal gyrus. Compared to the SZ-nMetS group, the SZ-MetS group exhibited a reduction in ReHo in the right inferior orbitofrontal gyrus. The ReHo of the right inferior orbitofrontal gyrus was significantly negatively correlated with BMI, waist circumference, and hip circumference in the SZ-MetS and SZ-nMetS groups. A reduction in ReHo in the right inferior orbitofrontal gyrus may thus be related to MetS in schizophrenia patients undergoing treatment. The findings may provide an imaging basis for brain alterations in patients with schizophrenia combined with MetS and provide a new insight into the neuroimaging mechanisms associated with MetS in patients with schizophrenia.

Biomarkers of cognitive and memory decline in psychotropic drug users

Psychotropic drugs are vital in psychiatry, aiding in the management of mental health disorders. Their use requires an understanding of their pharmacological properties, therapeutic applications, and potential side effects. Ongoing research aims to improve their efficacy and safety. Biomarkers play a crucial role in understanding and predicting memory decline in psychotropic drug users. A comprehensive understanding of biomarkers, including neuroimaging, biochemical, genetic, and cognitive assessments, is essential for developing targeted interventions and preventive strategies. In this narrative review, we performed a comprehensive search on PubMed and Google using review-specific terms. Clinicians should use a multifaceted approach, including neurotransmitter analysis, neurotrophic factors, miRNA profiling, and cognitive tasks for early intervention and personalized treatment. Anxiolytics' mechanisms involve various neurotransmitter systems and emerging targets. Research on biomarkers for memory decline in anxiolytic users can lead to early detection and intervention, enhancing clinical practices and aligning with precision medicine. Mood stabilizer users can benefit from early detection of memory decline through RNA, neurophysiological, and inflammatory biomarkers, promoting timely interventions. Performance-enhancing drugs may boost athletic performance in the short term, but their long-term health risks and ethical issues make their use problematic. Long-term use of psychotropic performance enhancers in athletes shows changes in biomarkers of cognitive decline, necessitating ongoing monitoring and intervention strategies. Understanding these genetic influences on memory decline helps pave the way for personalized approaches to prevent or mitigate cognitive deterioration, emphasizing the importance of genetic screening and early interventions based on an individual's genetic profile. Future research should focus on refining these biomarkers and protective measures against cognitive deterioration. Overall, a comprehensive understanding of biomarkers in psychotropic drug users is essential for developing targeted interventions and preventive strategies.

Bibliometric Analysis of Antipsychotic-induced Metabolic Disorder from 2006 to 2021 Based on WoSCC Database

BACKGROUND

With the frequent use of antipsychotics, the metabolic disorder (MetD) caused by drugs has received increasing attention. However, the mechanism of drug-induced MetD is still unclear and is being explored. Keeping abreast of the progress and trending knowledge in this area is conducive to further work.

OBJECTIVE

The aim of this study is to analyze the latest status and trends of research on antipsychoticinduced metabolic disorder (AIMetD) by bibliometric and visual analysis.

METHODS

3478 publications of AIMetD from 2006 to 2021 were retrieved from the Web of Science Core Collection database. R-biblioshiny was used for descriptive analysis, CiteSpace for cooperative network, co-citation analysis and burst detection, and VOSviewer for co-occurrence keywords was used.

RESULTS

Since 2006, the publications have been growing fluctuantly. These studies have extensive cooperation among countries/regions. The most influential country/region, institution and author are the USA, King's College London and Christoph U Correll. Analysis of references shows the largest cluster of "antipsychotic-induced metabolic dysfunction", which is an important basis for MetD. The recent contents of the burst citation are related to "glucose homeostasis" and "cardiovascular metabolism". Several bursting keywords were discerned at the forefront, including "LC-MS/MS", "major depressive disorder", "expression", and "homeostasis".

CONCLUSION

The AIMetD study is in a state of sustained development. Close cooperation between countries/ regions has promoted progress. For grasping the foundation, development, and latest trends of AIMetD, it is recommended to focus on active institutions and authors. Based on AIMetD, subdivision areas such as "LC-MS/MS", "expression", and "homeostasis" are forefronts that deserve constant attention.

Cannabidiol attenuates prepulse inhibition disruption by facilitating TRPV1 and 5-HT1A receptor-mediated neurotransmission

Individuals with schizophrenia (SCZ) often present sensorimotor gating impairments that can be investigated by the prepulse inhibition test (PPI). PPI disruption can be mimicked experimentally with psychostimulants such as amphetamine and attenuated/reversed by antipsychotics. Cannabidiol (CBD), the main non-psychotomimetic component of the Cannabis sativa plant, produces antipsychotic-like effects in clinical and preclinical studies. CBD can interact with many pharmacological targets, but the mechanisms involved in its antipsychotic activity are unclear. Using amphetamine-induced PPI disruption in mice, we investigated the involvement of four CBD potential pharmacological targets (CB1, CB2 TRPV1, and 5-HT1A receptors) in its antipsychotic properties. CBD effects were blocked by the TRPV1 antagonist capsazepine and, to a greater extent, by the 5-HT1A receptor antagonist WAY100635. No effect was observed with the CB1 (AM251) or CB2 (AM630) receptor antagonists. These results corroborate findings showing the antipsychotic effects of CBD in the PPI model and indicate that they involve the participation of TRPV1 and 5-HT1A receptors.

Neonatal outcomes after in utero exposure to antipsychotics: a systematic review and meta-analysis

Adverse neonatal outcomes following in utero antipsychotic exposure remain unclear. This systematic review and meta-analysis aimed to investigate associations between in utero first- and second-generation antipsychotic exposure and various neonatal outcomes. The primary outcome was small for gestational age. Secondary outcomes included other birth weight-related measures, prematurity and neonatal outcomes. MEDLINE, EMBASE, CENTRAL, ICTRP, and ClinicalTrials.gov were searched for on 8th July 2023. Two reviewers independently selected studies reporting associations between exposure and neonatal outcomes (all designs were eligible, no language or time restriction) and extracted data. ROBINS-I was used for risk of bias assessment. Meta-analyses were performed. Measures of association were odds ratios and mean differences. Thirty-one observational studies were included. Regarding small for gestational age < 10th percentile, meta-analysis was only performed for second-generation antipsychotics and showed no evidence for an association (OR 1.31 [95%CI 0.83; 2.07]; I²=46%; phet=0.13, n = 4 studies). First-generation antipsychotics were associated with an increased risk of small for gestational age < 3rd percentile (OR 1.37 [95%CI 1.02; 1.83]; I²=60%; phet=0.04, n = 5) and a lower mean birthweight (MD -135 g [95%CI -203; -66]; I²=53%; phet=0.07, n = 5). Second-generation antipsychotics were associated with large for gestational age > 97th percentile (OR 1.56 [95%CI 1.31; 1.87]; I²=4%; phet=0.37, n = 4) and Apgar score < 7 (OR 1.64 [95%CI 1.09; 2.47]; I²=47%; phet=0.13, n = 4). Both types of antipsychotics were associated with increased risks of preterm birth and neonatal hospitalization. Despite potential confounding in the studies, this systematic review and meta-analysis showed that newborns of mothers using antipsychotics during pregnancy are potentially at risk of adverse neonatal outcomes. Data sources: MEDLINE, EMBASE, CENTRAL, ICTRP, ClinicalTrials.gov. Prospero Registration Number CRD42023401805.

Pharmacological fingerprint of antipsychotic drugs at the serotonin 5-HT2A receptor

The intricate involvement of the serotonin 5-HT2A receptor (5-HT2AR) both in schizophrenia and in the activity of antipsychotic drugs is widely acknowledged. The currently marketed antipsychotic drugs, although effective in managing the symptoms of schizophrenia to a certain extent, are not without their repertoire of serious side effects. There is a need for better therapeutics to treat schizophrenia for which understanding the mechanism of action of the current antipsychotic drugs is imperative. With bioluminescence resonance energy transfer (BRET) assays, we trace the signaling signature of six antipsychotic drugs belonging to three generations at the 5-HT2AR for the entire spectrum of signaling pathways activated by serotonin (5-HT). The antipsychotic drugs display previously unidentified pathway preference at the level of the individual Gα subunits and β-arrestins. In particular, risperidone, clozapine, olanzapine and haloperidol showed G protein-selective inverse agonist activity. In addition, G protein-selective partial agonism was found for aripiprazole and cariprazine. Pathway-specific apparent dissociation constants determined from functional analyses revealed distinct coupling-modulating capacities of the tested antipsychotics at the different 5-HT-activated pathways. Computational analyses of the pharmacological and structural fingerprints support a mechanistically based clustering that recapitulate the clinical classification (typical/first generation, atypical/second generation, third generation) of the antipsychotic drugs. The study provides a new framework to functionally classify antipsychotics that should represent a useful tool for the identification of better and safer neuropsychiatric drugs and allows formulating hypotheses on the links between specific signaling cascades and in the clinical outcomes of the existing drugs.

Juvenile bright light exposure ameliorates adult behavioral abnormalities by enhancing neurogenesis in a N-methyl-D-aspartate receptor dysfunction mouse model relevant for cognitive impairment in schizophrenia

Exposure to light has been demonstrated to stimulate brain regions associated with cognition; however, investigations into its cognitive-enhancing effects have primarily focused on wild-type rodents. This study seeks to elucidate how bright light exposure mitigates cognitive deficits associated with schizophrenia by examining its impact on hippocampal neurogenesis and its potential to alleviate sub-chronic MK-801-induced cognitive impairments in mice. Following three weeks of juvenile bright light exposure (5-8 weeks old), significant increases in proliferating neurons (BrdU+) and immature neurons (DCX+ cells) were observed in the dentate gyrus (DG) and lateral ventricle of MK-801-treated mice. Long-term bright light treatment further promoted the differentiation of BrdU+ cells into immature neurons (BrdU+ DCX+ cells), mature neurons (BrdU+ NeuN+ cells), or astrocytes (BrdU+ GFAP+ cells) in the hippocampal DG. This augmented neurogenesis correlated with the attenuation of sub-chronic MK- 801-induced cognitive deficits, as evidenced by enhancements in Y-maze, novel object recognition (NOR), novel location recognition (NLR), and Morris water maze (MWM) test performances. These findings suggest a promising noninvasive clinical approach for alleviating cognitive impairments associated with neuropsychiatric disorders.

miR-486-5p-rich extracellular vesicles derived from patients with olanzapine-induced insulin resistance negatively affect glucose-regulating function

A high risk of glucometabolic disorder severely disturbs compliance and limits the clinical application of olanzapine. MicroRNAs (miRNAs) in extracellular vesicles (EVs) have been reported as emerging biomarkers in glucolipid metabolic disorders. A total of 81 individuals with continuous olanzapine treatment over 3 months were recruited in this study, and plasma EVs from these individuals were isolated and injected into rats via the tail vein to investigate the glucose-regulating function in vivo. Moreover, we performed a miRNA profiling assay by high through-put sequencing to clarify the differentiated miRNA profiles between two groups of patients who were either susceptible or not susceptible to olanzapine-induced insulin resistance (IR). Finally, we administered antagomir and cocultured them with adipocytes to explore the mechanism in vitro. The results showed that individual insulin sensitivity varied in those patients and in olanzapine-administered rats. Furthermore, treatment with circulating EVs from patients with olanzapine-induced IR led to the development of metabolic abnormalities in rats and adipocytes in vitro through the AKT-GLUT4 pathway. Deep sequencing illustrated that the miRNAs of plasma EVs from patients showed a clear difference based on susceptibility to olanzapine-induced IR, and miR-486-5p was identified as a notable gene. The adipocyte data indicated that miR-486-5p silencing partially reversed the impaired cellular insulin sensitivity. Collectively, this study confirmed the function of plasma EVs in the interindividual differences in olanzapine-induced insulin sensitivity.

MicroRNAs as potential biomarkers for diagnosis of schizophrenia and influence of antipsychotic treatment

ABSTRACT

Characterized by positive symptoms (such as changes in behavior or thoughts, including delusions and hallucinations), negative symptoms (such as apathy, anhedonia, and social withdrawal), and cognitive impairments, schizophrenia is a chronic, severe, and disabling mental disorder with late adolescence or early adulthood onset. Antipsychotics are the most commonly used drugs to treat schizophrenia, but those currently in use do not fully reverse all three types of symptoms characterizing this condition. Schizophrenia is frequently misdiagnosed, resulting in a delay of or inappropriate treatment. Abnormal expression of microRNAs is connected to brain development and disease and could provide novel biomarkers for the diagnosis and prognosis of schizophrenia. The recent studies reviewed included microRNA profiling in blood- and urine-based materials and nervous tissue materials. From the studies that had validated the preliminary findings, potential candidate biomarkers for schizophrenia in adults could be miR-22-3p, -30e-5p, -92a-3p, -148b-5p, -181a-3p, -181a-5p, -181b-5p, -199b-5p, -137 in whole blood, and miR-130b, -193a-3p in blood plasma. Antipsychotic treatment of schizophrenia patients was found to modulate the expression of certain microRNAs including miR-130b, -193a-3p, -132, -195, -30e, -432 in blood plasma. Further studies are warranted with adolescents and young adults having schizophrenia and consideration should be given to using animal models of the disorder to investigate the effect of suppressing or overexpressing specific microRNAs.

Cannabidiol as an antipsychotic drug

Cannabidiol (CBD) is a major phytocannabinoid in the Cannabis sativa plant. In contrast to Δ9-tetrahydrocannabinol (THC), CBD does not produce the typical psychotomimetic effects of the plant. In addition, CBD has attracted increased interest due to its potential therapeutic effects in various psychiatric disorders, including schizophrenia. Several studies have proposed that CBD has pharmacological properties similar to atypical antipsychotics. Despite accumulating evidence supporting the antipsychotic potential of CBD, the mechanisms of action in which this phytocannabinoid produces antipsychotic effects are still not fully elucidated. Here, we focused on the antipsychotic properties of CBD indicated by a series of preclinical and clinical studies and the evidence currently available about its possible mechanisms. Findings from preclinical studies suggest that CBD effects may depend on the animal model (pharmacological, neurodevelopmental, or genetic models for schizophrenia), dose, treatment schedule (acute vs. repeated) and route of administration (intraperitoneal vs local injection into specific brain regions). Clinical studies suggest a potential role for CBD in the treatment of psychotic disorders. However, future studies with more robust sample sizes are needed to confirm these positive findings. Overall, although more studies are needed, current evidence indicates that CBD may be a promising therapeutic option for the treatment of schizophrenia.

Decoding Clozapine-Induced Agranulocytosis: Unraveling Interactions and Mitigation Strategies

Agranulocytosis represents a severe complication associated with the administration of clozapine. Clozapine is an antipsychotic medication that has demonstrated substantial efficacy in remediating refractory schizophrenia and various other psychiatric disorders. Nonetheless, it is crucial to monitor patients for neutropenia regularly during clozapine therapy. Therefore, this article aimed to delve into the prevalence of agranulocytosis during clozapine treatment by scrutinizing the extant literature to discern trends and correlations. This review endeavored to explore factors such as drug interactions, dose-related factors, duration of treatment, and genetic predispositions that could potentially influence the likelihood of patients developing agranulocytosis while undergoing clozapine therapy. Moreover, this review enunciates the ramifications of agranulocytosis on both patients and healthcare providers and meticulously evaluates the strategies to mitigate this risk and ensure optimal patient outcomes.

Functional coupling between MC4R and Kir7.1 contributes to clozapine-induced hyperphagia

Most antipsychotic drugs (APDs) induce hyperphagia and weight gain. However, the neural mechanisms are poorly understood, partly due to challenges replicating their metabolic effects in rodents. Here, we report a new mouse model that recapitulates overeating induced by clozapine, a widely prescribed APD. Our study shows that clozapine boosts food intake by inhibiting melanocortin 4 receptor (MC4R) expressing neurons in the paraventricular nucleus of the hypothalamus. Interestingly, neither clozapine nor risperidone, another commonly used APD, affects receptor-ligand binding or the canonical Gαs signaling of MC4R. Instead, they inhibit neuronal activity by enhancing the coupling between MC4R and Kir7.1, leading to the open state of the inwardly rectifying potassium channel. Deletion of Kir7.1 in Mc4r-Cre neurons prevents clozapine-induced weight gain, while treatment with a selective Kir7.1 blocker mitigates overeating in clozapine-fed mice. Our findings unveil a molecular pathway underlying the effect of APDs on feeding behavior and suggest its potential as a therapeutic target.

Novel fluorescent probes based on sulfur and nitrogen co-doped carbon dots for determination of three N-substituted phenothiazine derivatives in dosage forms

In the current work, sulfur and nitrogen co-doped carbon dots (S,N-CDs) as simple, sensitive, and selective turn-off fluorescent nanosensors were utilized for analysis of three phenothiazine derivatives, including acetophenazine (APZ), chlorpromazine (CPH), and promethazine (PZH). S,N-CDs were synthesized through a green one-pot microwave-assisted technique using widely available precursors (thiourea and ascorbic acid). HRTEM, EDX, FTIR spectroscopy, UV-Vis absorption spectroscopy, and fluorescence spectroscopy were used to characterize the as-synthesized CDs. When excited at 330 nm, the carbon dots produced a maximum emission peak at 410 nm. The cited drugs statically quenched the S,N-CDs fluorescence as revealed by the Stern-Volmer equation. The current method represents the first spectrofluorimetric approach for the determination of the studied drugs without the need for chemical derivatization or harsh reaction conditions. The importance of the proposed work is magnified as the cited drugs do not have any fluorescent properties. The fluorescence of the developed sensor exhibited a linear response to APZ, CPH, and PZH in the concentration ranges of 5.0-100.0, 10.0-100.0, and 10.0-200.0 μM with detection limits of 1.53, 1.66, and 2.47 μM, respectively. The developed fluorescent probes have the advantages of rapidity and selectivity for APZ, CPH, and PZH analysis in tablets with acceptable % recoveries of (98.06-101.66 %). Evaluation of the method's greenness was performed using the Complementary Green Analytical Procedure Index (ComplexGAPI) and Analytical GREEnness metric (AGREE) metrics, indicating that the method is environmentally friendly. Validation of the proposed method was performed according to ICHQ2 (R1) guidelines.

Neuroleptic malignant syndrome and serotonin syndrome: a comparative bibliometric analysis

OBJECTIVE

This study aimed to analyze and map scientific literature on Neuroleptic Malignant Syndrome (NMS) and Serotonin Syndrome (SS) from prestigious, internationally indexed journals. The objective was to identify key topics, impactful articles, prominent journals, research output, growth patterns, hotspots, and leading countries in the field, providing valuable insights for scholars, medical students, and international funding agencies.

METHODS

A systematic search strategy was implemented in the PubMed MeSH database using specific keywords for NMS and SS. The search was conducted in the Scopus database, renowned for its extensive coverage of scholarly publications. Inclusion criteria comprised articles published from 1950 to December 31st, 2022, restricted to journal research and review articles written in English. Data were analyzed using Microsoft Excel for descriptive analysis, and VOSviewer was employed for bibliometric mapping.

RESULTS

The search yielded 1150 articles on NMS and 587 on SS, with the majority being case reports. Growth patterns revealed a surge in NMS research between 1981 and 1991, while SS research increased notably between 1993 and 1997. Active countries and journals differed between NMS and SS, with psychiatry journals predominating for NMS and pharmacology/toxicology journals for SS. Authorship analysis indicated higher multi-authored articles for NMS. Top impactful articles focused on review articles and pathogenic mechanisms. Research hotspots included antipsychotics and catatonia for NMS, while SS highlighted drug interactions and specific medications like linezolid and tramadol.

CONCLUSIONS

NMS and SS represent rare but life-threatening conditions, requiring detailed clinical and scientific understanding. Differential diagnosis and management necessitate caution in prescribing medications affecting central serotonin or dopamine systems, with awareness of potential drug interactions. International diagnostic tools and genetic screening tests may aid in safe diagnosis and prevention. Reporting rare cases and utilizing bibliometric analysis enhance knowledge dissemination and research exploration in the field of rare drug-induced medical conditions.

Therapeutic Drug Monitoring in Psychiatry: Enhancing Treatment Precision and Patient Outcomes

Psychiatric disorders often require pharmacological interventions to alleviate symptoms and improve quality of life. However, achieving an optimal therapeutic outcome is challenging due to several factors, including variability in the individual response, inter-individual differences in drug metabolism, and drug interactions in polytherapy. Therapeutic drug monitoring (TDM), by measuring drug concentrations in biological samples, represents a valuable tool to address these challenges, by tailoring medication regimens to each individual. This review analyzes the current landscape of TDM in psychiatric practice, highlighting its significance in optimizing drug dosages, minimizing adverse effects, and improving therapeutic efficacy. The metabolism of psychiatric medications (i.e., mood stabilizers, antipsychotics, antidepressants) often exhibits significant inter-patient variability. TDM can help address this variability by enhancing treatment personalization, facilitating early suboptimal- or toxic-level detection, and allowing for timely interventions to prevent treatment failure or adverse effects. Furthermore, this review briefly discusses technological advancements and analytical methods supporting the implementation of TDM in psychiatric settings. These innovations enable quick and cost-effective drug concentration measurements, fostering the widespread adoption of TDM as a routine practice in psychiatric care. In conclusion, the integration of TDM in psychiatry can improve treatment outcomes by individualizing medication regimens within the so-called precision medicine.

Revealing receptor-ligand interactions of atypical antipsychotic drugs and screening anti-schizophrenia ingredients in Magnolia officinalis based on 5-HTR2A-SNAP-Tag/CMC and DRD2-SNAP-Tag/CMC models

Schizophrenia is a serious mental illness with unknown etiology, and shows increasing incidence and high lifetime prevalence rate. The main receptors related to the disease are DRD2 and 5-HTR2A. Thus, a comprehensive understanding of the interaction mode between antipsychotic drugs with relevant receptors is very important for developing more effective drugs. 5-HTR2A-SNAP-Tag/CMC and DRD2-SNAP-Tag/CMC models constructed in this work provided a new method for studying the interaction between atypical antipsychotics and the two receptors. The results of comparative experiments showed that the new models not only met the high selectivity and specificity of the screening requirements but were also more stable and long-lasting than the traditional CMC model. Binding assays showed that the effects of three atypical antipsychotics (including clozapine, olanzapine, and quetiapine) on 5-HTR2A were stronger than their effects on DRD2. Additionally, two potentially active components, magnolol and honokiol, were screened in Magnolia officinalis methanol extract using the 5-HTR2A-SNAP-Tag/CMCHPLC-MS system. Nonlinear chromatographic analysis and molecular docking were conducted to study the interactions between screened compounds and the two receptors. The binding constants (KA) of magnolol and honokiol with 5-HTR2A were 17,854 ± 1,117 M-1 and 38,858 ± 4,964 M-1, respectively, and KA values with DRD2 were 4,872 ± 1,618 M-1 and 20,692 ± 10,267 M-1, respectively. We concluded that the established models are reliable for studying receptor-ligand interactions and screening antagonists of schizophrenia.

Safety, tolerability, and pharmacokinetics of JX11502MA in Chinese healthy subjects: a first-in-human, randomized, double-blind, placebo-controlled study following single-dose administration

BACKGROUND

JX11502MA is a potent partial agonist of dopamine D2 and D3 receptors, with a preferential binding profile for D3 receptors in vitro, potentially for treating schizophrenia.

METHODS

A first-in-human, randomized, double-blind, placebo-controlled, single ascending dose clinical trial was designed. The subjects were randomly assigned to receive JX11502MA and placebo capsules with seven ascending dose groups: 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, 6 mg, and 8 mg. The PK profiles of JX11502MA and its metabolites were evaluated, along with a safety and tolerability assessment.

RESULTS

Considering the safety of participants, the dose escalation was halted at 3 mg. Following single-dose administration, JX11502MA exhibited rapid absorption with a median Tmax ranging from 1 to 1.75 h. The terminal half-life of JX11502MA ranged from 73.62 to 276.85 h. The most common treatment-emergent adverse events (TEAEs) for subjects receiving JX11502MA were somnolence (56.3%), dizziness (18.8%), nausea (21.9%), vomiting (18.8%), and hiccups (18.8%).

CONCLUSIONS

JX11502MA was generally well tolerated at a single dose of 0.25 to 3 mg. The PK profiles and safety characteristics in this study indicated that JX11502MA has the potential to be a favorable treatment option for patients with schizophrenia.

TRIAL REGISTRATION

https://clinicaltrials.gov (identifier: NCT05233657).

Haloperidol alters neurotrophic factors and epigenetic parameters in an animal model of schizophrenia induced by ketamine

This study aimed to evaluate Haloperidol's (Hal) effects on the behavioral, neurotrophic factors, and epigenetic parameters in an animal model of schizophrenia (SCZ) induced by ketamine (Ket). Injections of Ket or saline were administered intraperitoneal (once a day) between the 1st and 14th days of the experiment. Water or Hal was administered via gavage between the 8th and 14th experimental days. Thirty minutes after the last injection, the animals were subjected to behavioral analysis. The activity of DNA methyltransferase (DNMT), histone deacetylase (HDAC), and histone acetyltransferase and levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin-3 (NT-3), and glial-derived neurotrophic factor (GDNF) were evaluated in the frontal cortex, hippocampus, and striatum. Ket increased the covered distance and time spent in the central area of the open field, and Hal did not reverse these behavioral alterations. Significant increases in the DNMT and HDAC activities were detected in the frontal cortex and striatum from rats that received Ket, Hal, or a combination thereof. Besides, Hal per se increased the activity of DNMT and HDAC in the hippocampus of rats. Hal per se or the association of Ket plus Hal decreased BDNF, NGF, NT-3, and GDNF, depending on the brain region and treatment regimen. The administration of Hal can alter the levels of neurotrophic factors and the activity of epigenetic enzymes, which can be a factor in the development of effect collateral in SCZ patients. However, the precise mechanisms involved in these alterations are still unclear.

Augmentation therapy with serotonin1A receptor partial agonists on neurocognitive function in schizophrenia: A systematic review and meta-analysis

Background

In a previous meta-analysis, the use of serotonin1A(5-HT1A) receptor partial agonists of the azapirone class as an add-on therapy was associated with beneficial effects on positive symptoms and attention/processing speed in schizophrenia patients. This meta-analysis builds on that study by examining the effects of adjunctive treatment with 5-HT1A partial agonists in improving other domains of neurocognitive function in schizophrenia patients.

Methods

A literature search was performed from 1987 to May 2023 to identify randomized controlled trials. The standardized mean difference (SMD) with 95 % confidence intervals (CI) was calculated when there were two or more studies. Four studies, involving 313 patients, met the inclusion criteria and were used in the analysis.

Results

5-HT1A partial agonists (buspirone or tandospirone) did not have a significant effect on verbal learning (SMD = 0.08, 95 % CI = -0.31 to 0.47) or working memory (SMD = 0.15, 95 % CI = -0.09 to 0.39). Regarding executive functions (Wisconsin Card Sorting Test), positive but non-significant results were seen with the category number (SMD = 0.26, 95 % CI = -0.81 to 1.32), while non-significant effects were noted for percent preservation errors (SMD = -0.10, 95 % CI = -0.53 to 0.33).

Conclusions

The absence of any significant benefits in the cognitive domains studied here may have been due to the variance in the concomitant medication (typical vs atypical antipsychotic drugs), the level of cognition at baseline, or other factors. Further studies with various types of 5-HT1A agonists are warranted to examine the potential cognitive efficacy of stimulating these receptors.

Evaluation of neuroleptic malignant syndrome induced by antipsychotic drugs using spontaneous reporting system

Adverse events (AEs) of antipsychotic drugs include neuroleptic malignant syndrome (NMS), which presents complex clinical symptoms, resulting in a fatal outcome. In this study, the association between antipsychotic drugs and NMS was comprehensively evaluated by cluster and association analyses using the Japanese Adverse Drug Event Report (JADER) database. The analyses were performed using 20 typical antipsychotics (TAPs) alongside 9 atypical antipsychotics (AAPs). The Standardised MedDRA Queries (SMQ) database was used to analyze NMS (SMQ code: 20000044). Reporting odds ratios (RORs) were used for AE signal detection. The relationship between antipsychotic drugs and AEs for NMS was investigated by performing hierarchical cluster analysis using Ward's method. Between April 2004 and September 2021, the total number of JADER reports was 705,294. RORs (95 % confidence interval) of NMS for haloperidol, chlorpromazine, risperidone, and aripiprazole were 12.1 (11.1-13.3), 6.3 (5.7-7.0), 6.2 (5.8-6.6), and 4.7 (4.4-5.1), respectively. Three clusters were formed, with characteristics as follows: Cluster 1 consisted of only TAPs, such as bromperidol and fluphenazine, whilst having a high reporting rate of hypotension, tachycardia, dyskinesia, and dystonia. Cluster 2 consisted of all AAPs alongside several TAPs, such as haloperidol and chlorpromazine, with higher reporting rates of disturbance of consciousness, extrapyramidal disorders (excluding dyskinesia and dystonia), and serotonin syndrome. Cluster 3 consisted of only perphenazine, whilst having a higher reporting rate of coma, leukocytosis, and Parkinsonism. The results of this study may therefore aid in the management of NMS using antipsychotic drugs.

Mechanisms and molecular targets surrounding the potential therapeutic effects of psychedelics

Psychedelics, also known as classical hallucinogens, have been investigated for decades due to their potential therapeutic effects in the treatment of neuropsychiatric and substance use disorders. The results from clinical trials have shown promise for the use of psychedelics to alleviate symptoms of depression and anxiety, as well as to promote substantial decreases in the use of nicotine and alcohol. While these studies provide compelling evidence for the powerful subjective experience and prolonged therapeutic adaptations, the underlying molecular reasons for these robust and clinically meaningful improvements are still poorly understood. Preclinical studies assessing the targets and circuitry of the post-acute effects of classical psychedelics are ongoing. Current literature is split between a serotonin 5-HT2A receptor (5-HT2AR)-dependent or -independent signaling pathway, as researchers are attempting to harness the mechanisms behind the sustained post-acute therapeutically relevant effects. A combination of molecular, behavioral, and genetic techniques in neuropharmacology has begun to show promise for elucidating these mechanisms. As the field progresses, increasing evidence points towards the importance of the subjective experience induced by psychedelic-assisted therapy, but without further cross validation between clinical and preclinical research, the why behind the experience and its translational validity may be lost.

A Novel Gliotransmitter, L-β-Aminoisobutyric Acid, Contributes to Pathophysiology of Clinical Efficacies and Adverse Reactions of Clozapine

Clozapine is listed as one of the most effective antipsychotics and has been approved for treating treatment-resistant schizophrenia (TRS); however, several type A and B adverse reactions, including weight gain, metabolic complications, cardiotoxicity, convulsions, and discontinuation syndromes, exist. The critical mechanisms of clinical efficacy for schizophrenia, TRS, and adverse reactions of clozapine have not been elucidated. Recently, the GABA isomer L-β-aminoisobutyric acid (L-BAIBA), a protective myokine in the peripheral organs, was identified as a candidate novel transmission modulator in the central nervous system (CNS). L-BAIBA activates adenosine monophosphate-activated protein kinase (AMPK) signalling in both the peripheral organs and CNS. Activated AMPK signalling in peripheral organs is an established major target for treating insulin-resistant diabetes, whereas activated AMPK signalling in the hypothalamus contributes to the pathophysiology of weight gain and metabolic disturbances. Clozapine increases L-BAIBA synthesis in the hypothalamus. In addition, the various functions of L-BAIBA in the CNS have recently been elucidated, including as an activator of GABA-B and group-III metabotropic glutamate (III-mGlu) receptors. Considering the expressions of GABA-B and III-mGlu receptors (localised in the presynaptic regions), the activation of GABA-B and III-mGlu receptors can explain the distinct therapeutic advantages of clozapine in schizophrenia or TRS associated with N-methyl-D-aspartate (NMDA) receptor disturbance compared with other atypical antipsychotics via the inhibition of the persistent tonic hyperactivation of thalamocortical glutamatergic transmission in the prefrontal cortex. L-BAIBA has also been identified as a gliotransmitter, and a detailed exploration of the function of L-BAIBA in tripartite synaptic transmission can further elucidate the pathophysiology of effectiveness for treating TRS and/or specific adverse reactions of clozapine.

Pharmacological and Physicochemical Properties Optimization for Dual-Target Dopamine D3 (D3R) and μ-Opioid (MOR) Receptor Ligands as Potentially Safer Analgesics

A new generation of dual-target μ opioid receptor (MOR) agonist/dopamine D3 receptor (D3R) antagonist/partial agonists with optimized physicochemical properties was designed and synthesized. Combining in vitro cell-based on-target/off-target affinity screening, in silico computer-aided drug design, and BRET functional assays, we identified new structural scaffolds that achieved high affinity and agonist/antagonist potencies for MOR and D3R, respectively, improving the dopamine receptor subtype selectivity (e.g., D3R over D2R) and significantly enhancing central nervous system multiparameter optimization scores for predicted blood-brain barrier permeability. We identified the substituted trans-(2S,4R)-pyrrolidine and trans-phenylcyclopropyl amine as key dopaminergic moieties and tethered these to different opioid scaffolds, derived from the MOR agonists TRV130 (3) or loperamide (6). The lead compounds 46, 84, 114, and 121 have the potential of producing analgesic effects through MOR partial agonism with reduced opioid-misuse liability via D3R antagonism. Moreover, the peripherally limited derivatives could have therapeutic indications for inflammation and neuropathic pain.

Antipsychotic drug efficacy correlates with the modulation of D1 rather than D2 receptor-expressing striatal projection neurons

Elevated dopamine transmission in psychosis is assumed to unbalance striatal output through D1- and D2-receptor-expressing spiny-projection neurons (SPNs). Antipsychotic drugs are thought to re-balance this output by blocking D2 receptors (D2Rs). In this study, we found that amphetamine-driven dopamine release unbalanced D1-SPN and D2-SPN Ca2+ activity in mice, but that antipsychotic efficacy was associated with the reversal of abnormal D1-SPN, rather than D2-SPN, dynamics, even for drugs that are D2R selective or lacking any dopamine receptor affinity. By contrast, a clinically ineffective drug normalized D2-SPN dynamics but exacerbated D1-SPN dynamics under hyperdopaminergic conditions. Consistent with antipsychotic effect, selective D1-SPN inhibition attenuated amphetamine-driven changes in locomotion, sensorimotor gating and hallucination-like perception. Notably, antipsychotic efficacy correlated with the selective inhibition of D1-SPNs only under hyperdopaminergic conditions-a dopamine-state-dependence exhibited by D1R partial agonism but not non-antipsychotic D1R antagonists. Our findings provide new insights into antipsychotic drug mechanism and reveal an important role for D1-SPN modulation.

The crosstalk between 5-HT2AR and mGluR2 in schizophrenia

Schizophrenia is a severe brain disorder that usually produces a lifetime of disability. First generation or typical antipsychotics such as haloperidol and second generation or atypical antipsychotics such as clozapine and risperidone remain the current standard for schizophrenia treatment. In some patients with schizophrenia, antipsychotics produce complete remission of positive symptoms, such as hallucinations and delusions. However, antipsychotic drugs are ineffective against cognitive deficits and indeed treated schizophrenia patients have small improvements or even deterioration in several cognitive domains. This underlines the need for novel and more efficient therapeutic targets for schizophrenia treatment. Serotonin and glutamate have been identified as key parts of two neurotransmitter systems involved in fundamental brain processes. Serotonin (or 5-hydroxytryptamine) 5-HT2A receptor (5-HT2AR) and metabotropic glutamate 2 receptor (mGluR2) are G protein-coupled receptors (GPCRs) that interact at epigenetic and functional levels. These two receptors can form GPCR heteromeric complexes through which their pharmacology, function and trafficking becomes affected. Here we review past and current research on the 5-HT2AR-mGluR2 heterocomplex and its potential implication in schizophrenia and antipsychotic drug action. This article is part of the Special Issue on "The receptor-receptor interaction as a new target for therapy".

Steroid-induced psychosis related to pituitary adenoma status post trans-sphenoid excision and a history of psychiatric illness: A case report

BACKGROUND

Steroid-induced psychosis is a common adverse effect of steroid exposure. Reported cases were mostly related to rheumatologic disease. Despite its high incidence, there is only one case reported related to perioperative steroid replacement for pituitary adenoma surgery. This manuscript presents the second case of such and compared the two with the latest literature review of steroid-induced psychosis.

CASE SUMMARY

This is a case of an adult male with a chief complaint of auditory hallucinations and was referred by Neurosurgery to Psychiatry Out-patient department. He was diagnosed with pituitary adenoma who underwent trans-sphenoid excision of the mass from which steroid exposure led to steroid-induced psychosis. Also, patient had a history of psychiatric illness of severe depressive episode. At the out-patient department, patient was started on antipsychotic, Risperidone, which led to eventual improvement of his symptoms.

CONCLUSION

The two cases of pituitary adenoma surgery with steroid-induced psychosis had almost similar clinical profile with the latest literature review of steroid-induced psychosis. However, the present case highlights the association of psychiatric illness in predisposing an individual in developing it. Also, this manuscript emphasizes that early recognition of steroid-induced psychosis leads to better prognosis. Multispecialty treatment is vital in the holistic management of the patient with timely referral and close coordination.

Insights into the Potential Impact of Quetiapine on the Microglial Trajectory and Inflammatory Response in Organotypic Cortical Cultures Derived from Rat Offspring

Atypical antipsychotics currently constitute the first-line medication for schizophrenia, with quetiapine being one of the most commonly prescribed representatives of the group. Along with its specific affinity for multiple receptors, this compound exerts other biological characteristics, among which anti-inflammatory effects are strongly suggested. Simultaneously, published data indicated that inflammation and microglial activation could be diminished by stimulation of the CD200 receptor (CD200R), which takes place by binding to its ligand (CD200) or soluble CD200 fusion protein (CD200Fc). Therefore, in the present study, we sought to evaluate whether quetiapine could affect certain aspects of microglial activity, including the CD200-CD200R and CX3CL1-CX3CR1 axes, which are involved in the regulation of neuron-microglia interactions, as well as the expression of selected markers of the pro- and anti-inflammatory profile of microglia (Cd40, Il-1β, Il-6, Cebpb, Cd206, Arg1, Il-10 and Tgf-β). Concurrently, we examined the impact of quetiapine and CD200Fc on the IL-6 and IL-10 protein levels. The abovementioned aspects were investigated in organotypic cortical cultures (OCCs) prepared from the offspring of control rats (control OCCs) or those subjected to maternal immune activation (MIA OCCs), which is a widely implemented approach to explore schizophrenia-like disturbances in animals. The experiments were performed under basal conditions and after additional exposure to the bacterial endotoxin lipopolysaccharide (LPS), according to the "two-hit" hypothesis of schizophrenia. The results of our research revealed differences between control and MIA OCCs under basal conditions and in response to treatment with LPS in terms of lactate dehydrogenase and nitric oxide release as well as Cd200r, Il-1β, Il-6 and Cd206 expression. The additional stimulation with the bacterial endotoxin resulted in a notable change in the mRNA levels of pro- and anti-inflammatory microglial markers in both types of OCCs. Quetiapine diminished the influence of LPS on Il-1β, Il-6, Cebpb and Arg1 expression in control OCCs as well as on IL-6 and IL-10 levels in MIA OCCs. Moreover, CD200Fc reduced the impact of the bacterial endotoxin on IL-6 production in MIA OCCs. Thus, our results demonstrated that quetiapine, as well as the stimulation of CD200R by CD200Fc, beneficially affected LPS-induced neuroimmunological changes, including microglia-related activation.

Atypical antipsychotic-induced mania: A systematic review and meta-analysis

BACKGROUND

The possibility of atypical antipsychotics (AA) to induce manic symptoms has been raised by several articles. The objective of this study was to describe whether exposure to AA may induce mania in mood disorders.

METHODS

We performed a systematic review following the preferred reporting items for systematic reviews and meta-analysis guidelines. The systematic search encompassed all relevant studies published until April 4th, 2022. A meta-analysis testing whether treatment emergent mania (TEM) is more frequent with the use of AA compared with placebo was performed.

RESULTS

A total of 52 studies were included in the systematic review. We found 24 case reports or case series describing 40 manic/hypomanic episodes allegedly induced by AA. Twenty-one placebo-controlled trials were included in a meta-analysis including 4823 individuals treated with AA and 3252 individuals receiving placebo. Our meta-analysis showed that the use of AA protects against the development of TEM (OR: 0.68 [95 % CI: 0.52-0.89], p = 0.005).

LIMITATIONS

AA-induced mania/hypomania was not the primary outcome in any of the observational or interventional studies. TEM was not homogeneously defined across studies. In most case reports it was not possible to establish causality between the use of AA and the development of manic symptoms.

CONCLUSIONS

TEM is more frequent with placebo than with AA, which suggests that AA exposure does not represent a relevant risk for TEM. Mania/hypomania induced by an AA seems to be rare events, since anecdotal evidence from case reports and case series were not observed in observational prospective and interventional studies.

The Influence of Antipsychotic Treatment on the Activity of Abzymes Targeting Myelin and Levels of Inflammation Markers in Patients with Schizophrenia

Catalytic antibodies, or abzymes, are capable of not only binding but also hydrolyzing various proteins. Previously, an increase in the level of myelin basic protein (MBP)-hydrolyzing activity of antibodies was shown in patients with a number of neurological and mental disorders, including schizophrenia. Furthermore, antipsychotic therapy is known to induce a change in cytokine levels in patients with schizophrenia, which affects regulation of the immune response and inflammatory status. This study investigated the influence of typical and atypical antipsychotics on catalytic antibody activity and the 10 major pro- and anti-inflammatory serum cytokine levels. The study included 40 patients with schizophrenia: 15 treated with first-generation antipsychotics and 25 treated with atypical antipsychotics for 6 weeks. It was found that treatment with atypical antipsychotics changed the levels of some pro-inflammatory cytokines. Antipsychotic therapy also caused a significant decrease in MBP-hydrolyzing activity in patients with schizophrenia (p = 0.0002), and associations of catalytic activity with interleukins were observed.

Unique effect of clozapine on adenosine A2A-dopamine D2 receptor heteromerization

The striatal dopamine D2 receptor (D2R) is generally accepted to be involved in positive symptoms of schizophrenia and is a main target for clinically used antipsychotics. D2R are highly expressed in the striatum, where they form heteromers with the adenosine A2A receptor (A2AR). Changes in the density of A2AR-D2R heteromers have been reported in postmortem tissue from patients with schizophrenia, but the degree to which A2R are involved in schizophrenia and the effect of antipsychotic drugs is unknown. Here, we examine the effect of exposure to three prototypical antipsychotic drugs on A2AR-D2R heteromerization in mammalian cells using a NanoBiT assay. After 16 h of exposure, a significant increase in the density of A2AR-D2R heteromers was found with haloperidol and aripiprazole, but not with clozapine. On the other hand, clozapine, but not haloperidol or aripiprazole, was associated with a significant decrease in A2AR-D2R heteromerization after 2 h of treatment. Computational binding models of these compounds revealed distinctive molecular signatures that explain their different influence on heteromerization. The bulky tricyclic moiety of clozapine displaces TM 5 of D2R, inducing a clash with A2AR, while the extended binding mode of haloperidol and aripiprazole stabilizes a specific conformation of the second extracellular loop of D2R that enhances the interaction with A2AR. It is proposed that an increase in A2AR-D2R heteromerization is involved in the extrapyramidal side effects (EPS) of antipsychotics and that the specific clozapine-mediated destabilization of A2AR-D2R heteromerization can explain its low EPS liability.

Sex difference in association between tardive dyskinesia and cognitive deficits in patients with chronic schizophrenia

BACKGROUND

Tardive dyskinesia (TD), a side effect due to long-term use of antipsychotic medication, is associated with cognitive impairment. Several studies have found sex differences in cognitive impairment in schizophrenia patients, while whether there are sex differences in cognitive performance in schizophrenia patients with TD has not been reported.

METHODS

A total of 496 schizophrenia inpatients and 362 healthy controls were recruited for this study. We used the Positive and Negative Syndrome Scale (PANSS) to assess patients' psychopathological symptoms and the Abnormal Involuntary Movement Scale (AIMS) to assess the severity of TD. Cognitive function was measured in 313 of these inpatients and 310 of healthy controls using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS).

RESULTS

Patients with schizophrenia performed worse in all cognitive domains than healthy controls(all p < 0.001). Compared to patients without TD, patients with TD had higher PANSS total, PANSS negative symptom subscale and AIMS scores (all p < 0.001), while RBANS total, visuospatial/constructional and attention subscale scores were significantly lower (all p < 0.05). In addition, the visuospatial/constructional and attention indices remained significantly lower in male patients with TD than those without TD (both p < 0.05), but these results were not observed in female patients. Moreover, visuospatial/constructional and attention indices were negatively correlated with total AIMS scores only in male patients (both p < 0.05).

CONCLUSION

Our results suggest that there may be sex differences in cognitive impairment in schizophrenia patients with comorbid TD, indicating that female gender may have a protective effect on cognitive impairment in schizophrenia patients caused by TD.

Adolescent raloxifene treatment in females prevents cognitive deficits in a neurodevelopmental rodent model of schizophrenia

The existence of sex differences in schizophrenia is a well documented phenomenon which led to the hypothesis that female sex hormones are neuroprotective and hence responsible for the more favorable disease characteristics seen in women. The current study sought to investigate the effects of estrogen-like agents administered during early adolescence on behavioral outcomes in adulthood using the neurodevelopmental maternal immune activation (MIA) rodent model of schizophrenia. Female MIA offspring were administered during the asymptomatic period of adolescence with either 17β-estradiol, raloxifene or saline and were tested in late adolescence and adulthood for schizophrenia-related behavioral performance. We report here that whereas adult female MIA offspring exhibited cognitive deficits in the form of retarded spatial learning, the administration of raloxifene during adolescence was sufficient in preventing these deficits and resulted in intact performance in the MIA group.

Dopamine D3/D2 Receptor Ligands Based on Cariprazine for the Treatment of Psychostimulant Use Disorders That May Be Dual Diagnosed with Affective Disorders

Highly selective dopamine D3 receptor (D3R) partial agonists/antagonists have been developed for the treatment of psychostimulant use disorders (PSUD). However, none have reached the clinic due to insufficient potency/efficacy or potential cardiotoxicity. Cariprazine, an FDA-approved drug for the treatment of schizophrenia and bipolar disorder, is a high-affinity D3R partial agonist (Ki = 0.22 nM) with 3.6-fold selectivity over the homologous dopamine D2 receptor (D2R). We hypothesized that compounds that are moderately D3R/D2R-selective partial agonists/antagonists may be effective for the treatment of PSUD. By systematically modifying the parent molecule, we discovered partial agonists/antagonists, as measured in bioluminescence resonance energy transfer (BRET)-based assays, with high D3R affinities (Ki = 0.14-50 nM) and moderate selectivity (<100-fold) over D2R. Cariprazine and two lead analogues, 13a and 13e, decreased cocaine self-administration (FR2; 1-10 mg/kg, i.p.) in rats, suggesting that partial agonists/antagonists with modest D3R/D2R selectivity may be effective in treating PSUD and potentially comorbidities with other affective disorders.

Identification and Characterization of ML321: A Novel and Highly Selective D2 Dopamine Receptor Antagonist with Efficacy in Animal Models That Predict Atypical Antipsychotic Activity

We have developed and characterized a novel D2R antagonist with exceptional GPCR selectivity - ML321. In functional profiling screens of 168 different GPCRs, ML321 showed little activity beyond potent inhibition of the D2R and to a lesser extent the D3R, demonstrating excellent receptor selectivity. The D2R selectivity of ML321 may be related to the fact that, unlike other monoaminergic ligands, ML321 lacks a positively charged amine group and adopts a unique binding pose within the orthosteric binding site of the D2R. PET imaging studies in non-human primates demonstrated that ML321 penetrates the CNS and occupies the D2R in a dose-dependent manner. Behavioral paradigms in rats demonstrate that ML321 can selectively antagonize a D2R-mediated response (hypothermia) while not affecting a D3R-mediated response (yawning) using the same dose of drug, thus indicating exceptional in vivo selectivity. We also investigated the effects of ML321 in animal models that are predictive of antipsychotic efficacy in humans. We found that ML321 attenuates both amphetamine- and phencyclidine-induced locomotor activity and restored pre-pulse inhibition (PPI) of acoustic startle in a dose-dependent manner. Surprisingly, using doses that were maximally effective in both the locomotor and PPI studies, ML321 was relatively ineffective in promoting catalepsy. Kinetic studies revealed that ML321 exhibits slow-on and fast-off receptor binding rates, similar to those observed with atypical antipsychotics with reduced extrapyramidal side effects. Taken together, these observations suggest that ML321, or a derivative thereof, may exhibit ″atypical″ antipsychotic activity in humans with significantly fewer side effects than observed with the currently FDA-approved D2R antagonists.

Use of antipsychotic medication and its relationship with bone mineral density: A population-based study of men and women

Background

Schizophrenia has been shown to be associated with reduced bone mineral density (BMD) and higher fracture risk. However, less is known whether antipsychotic treatment is associated with reduced BMD. Thus, we aimed to examine associations between antipsychotic use and BMD among men and women drawn from the general population.

Methods

This cross-sectional study involved 793 women and 587 men enrolled in the Geelong Osteoporosis Study (GOS). BMD was determined using dual-energy X-ray absorptiometry at the spine and hip. Information regarding socio-economic status (SES), current medication and/or supplementation use, lifestyle factors, and anthropometry was collected. Association between antipsychotic use and BMD was determined using linear regression after adjusting for potential confounders.

Results

Of the group, 33 women (4.2%) and 16 men (2.7%) currently used antipsychotics. Age was identified as an effect modifier in the association between antipsychotic use and BMD for women. Amongst women aged < 60 years, adjusted mean BMD was 11.1% lower at the spine [1.139 (95%CI 1.063-1.216) vs. 1.250 (95%CI 1.223-1.277) g/cm2, p = 0.005] for antipsychotic users compared to non-users. At the hip, age, weight, and smoking adjusted mean BMD was 9.9% lower [0.893 (95%CI 0.837-0.950) vs. 0.992 (95%CI 0.976-1.007) g/cm2, p < 0.001] for antipsychotic users in comparison with non-users. The pattern persisted following further adjustments. There was no association detected between antipsychotic use and BMD for women aged 60 years and over and for men.

Conclusion

Our data suggest that antipsychotic medication use is associated with reduced BMD in younger women but not older women or men.

Early Efficacy of Antipsychotic Medications at Week 2 Predicts Subsequent Responses at Week 6 in a Large-scale Randomized Controlled Trial

BACKGROUND

Since the early clinical efficacy of antipsychotics has not yet been well perceived, this study sought to decide whether the efficacy of antipsychotics at week 2 can predict subsequent responses at week 6 and identify how such predictive capacities vary among different antipsychotics and psychotic symptoms.

METHODS

A total of 3010 patients with schizophrenia enrolled in a randomized controlled trial (RCT) and received a 6-week treatment with one antipsychotic drug randomly chosen from five atypical antipsychotics (risperidone 2-6 mg/d, olanzapine 5-20 mg/d, quetiapine 400-750 mg/d, aripiprazole 10-30 mg/d, and ziprasidone 80-160 mg/d) and two typical antipsychotics (perphenazine 20-60 mg/d and haloperidol 6-20 mg/d). Early efficacy was defined as the reduction rate using the Positive and Negative Syndrome Scale (PANSS) total score at week 2. With cut-offs at 50% reduction, logistic regression, receiver operating characteristic (ROC) and random forests were adopted.

RESULTS

The reduction rate of PANSS total score and improvement of psychotic symptoms at week 2 enabled subsequent responses to 7 antipsychotics to be predicted, in which improvements in delusions, lack of judgment and insight, unusual thought content, and suspiciousness/ persecution were endowed with the greatest weight.

CONCLUSION

It is robust enough to clinically predict treatment responses to antipsychotics at week 6 using the reduction rate of PANSS total score and symptom relief at week 2. Psychiatric clinicians had better determine whether to switch the treatment plan by the first 2 weeks.

Antipsychotic exposure is an independent risk factor for breast cancer: A systematic review of epidemiological evidence

Background

The effect of antipsychotics on breast cancer remains controversial.

Materials and methods

Embase, Scopus, PubMed, Web of Science, Cochrane Library, and Hebei Medical University Library were used for the literature search. Observational studies with original data for the effects of antipsychotics on breast cancer were used. Studies of bed quality, those with inadequate sample size, incomplete follow-up works, or studies that did not meet the criteria were excluded. Meta-analysis was performed using R version 4.1.2. The odds ratio (OR) and its 95% confidence interval (CI) were used to evaluate the proportion of breast cancer in different groups. To detect possible sources of heterogeneity, subgroup and meta-regression analyses were employed.

Results

Pooled data from 11 relevant studies with 1,499,001 participants suggested that individuals exposed to antipsychotics were more likely to suffer from breast cancer than those who were not exposed (OR, 1.23; 95% CI, 1.04-1.47). No significant difference in breast cancer prevalence between the atypical and typical antipsychotic groups was found (OR, 1.23; 95% CI, 0.93-1.63). Prolactin (PRL)-increasing and PRL-sparing antipsychotics posed a similar risk of breast cancer (OR, 1.13; 95% CI, approximately 0.97-1.31). Furthermore, the use of antipsychotics is attributed to increased mortality in patients with breast cancer (OR, 1.54; 95% CI, 1.29-1.82). Those exposed to antipsychotics at the maximum dose were more likely to suffer from breast cancer than those exposed to the minimum dose.

Conclusions

Antipsychotic exposure is an independent risk factor for breast cancer. No significant difference in the risk of breast cancer between typical and atypical antipsychotics was noted. Those exposed to antipsychotics at higher doses are more likely to suffer from breast cancer. Moreover, the use of antipsychotics is attributed to increased mortality in patients with breast cancer. PRL-increasing and PRL-sparing antipsychotics pose a similar risk of breast cancer.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022307624.

NRG1 knockdown rescues PV interneuron GABAergic maturation deficits and schizophrenia behaviors in fetal growth restriction mice

Schizophrenia is a highly debilitating mental disorder, those who experienced fetal growth restriction (FGR) in the early stage of life have a greater probability of schizophrenia. In this study, FGR mice showed hyperactivity in locomotor activity test, sociability dysfunction in three chamber test and nesting social behavior tests, cognition decline in Morris water maze and impaired sensory motor gating function in prepulse inhibition test. Mechanistic studies indicated that the number of parvalbumin (PV) interneuron was significantly reduced in FGR mouse media prefrontal cortex (mPFC). And the mRNA and protein level of neuregulin 1(NRG1), which is a critical schizophrenia gene, increased significantly in FGR mouse mPFC. Furthermore, NRG1 knockdown in FGR mouse mPFC improved PV interneuron GABAergic maturation and rescued schizophrenia behaviors including hyperactivity, social novelty defects, cognition decline, and sensorimotor gating deficits in FGR mice. This study indicates that mPFC NRG1 upregulation is one of the main causes of FGR-induced schizophrenia, which leads to significant reduction of PV interneuron number in mPFC. NRG1 knockdown in mPFC significantly rescues schizophrenia behaviors in FGR mouse. This study thus provides a potential effective therapy target or strategy for schizophrenia patients induced by FGR.

TAAR1 dependent and independent actions of the potential antipsychotic and dual TAAR1/5-HT1A receptor agonist SEP-383856

SEP-383856 (SEP-856) is a novel antipsychotic under clinical development. It displays a unique pattern of receptor interaction, with only weak (partial agonist) activity at dopamine D₂ receptors, yet more potent agonist activity at the trace amine associated receptor (TAAR1) and 5-hydroxytryptamine 1 A receptor (5-HT_1A). Nonetheless, these observations await independent confirmation and more detailed characterization of the in vitro and in vivo actions of SEP-856 at TAAR1 and 5-HT_1A receptors would be instructive. Herein, we employed luminescence complementation technology in heterologous live cell systems, confocal microscopy, voltage clamp electrophysiology, behavioral readouts and TAAR1 knockout (KO) mice to study SEP-856 in further detail. We provide evidence for the ability of SEP-856 to activate TAAR1 at the surface plasma membrane, and show that this interaction results in Gα_s recruitment (pEC₅₀: 6.08 ± 0.22 E_MAX: 96.41% ± 15.26) and by extension, to G-protein inwardly rectifying potassium (GIRK) channel activation. Using TAAR1-KO mice, we find TAAR1 to be indispensable for SEP-856 control of body temperature, baseline locomotion reduction and for "antipsychotic-like" efficacy as characterized by a reversal of dizocilipine (MK-801) mediated disruption of pre-pulse inhibition. Conversely, the inhibition by SEP-856 of MK-801 induced locomotion was unaffected in TAAR1 KO mice. SEP-856 behaved as a low-potency, partial agonist at the 5-HT_1A receptor, while it partially inhibited recruitment of D₂ receptor-coupled Gα and GIRK by DA and acted as a weak partial agonist with low potency at the same receptor when applied alone. Our findings corroborate and extend previous observations on the molecular substrates engaged by this unique, dual TAAR1/5-HT_1A receptor agonist and potential antipsychotic that could prove to have major advantages in the treatment of schizophrenia and other psychotic disorders.

Protein Glutathionylation and Glutaredoxin: Role in Neurodegenerative Diseases

Oxidative stress has been implicated in the pathogenesis and progression of many neurodegenerative disorders including Parkinson's disease and Alzheimer's disease. One of the major enzyme systems involved in the defense against reactive oxygen species are the tripeptide glutathione and oxidoreductase glutaredoxin. Glutathione and glutaredoxin system are very important in the brain because of the oxidative modification of protein thiols to protein glutathione mixed disulfides with the concomitant formation of oxidized glutathione during oxidative stress. Formation of Pr-SSG acts as a sink in the brain and is reduced back to protein thiols during recovery, thus restoring protein functions. This is unlike in the liver, which has a high turnover of glutathione, and formation of Pr-SSG is very minimal as liver is able to quickly quench the prooxidant species. Given the important role glutathione and glutaredoxin play in the brain, both in normal and pathologic states, it is necessary to study ways to augment the system to help maintain the protein thiol status. This review details the importance of glutathione and glutaredoxin systems in several neurodegenerative disorders and emphasizes the potential augmentation of this system as a target to effectively protect the brain during aging.

The interplay of dopamine metabolism abnormalities and mitochondrial defects in the pathogenesis of schizophrenia

Dopamine (DA) is a major monoamine neurotransmitter in the brain and has essential roles in higher functions of the brain. Malfunctions of dopaminergic signaling have been implicated in various mental disorders such as addiction, attention deficit/hyperactivity disorder, Huntington's disease, Parkinson's disease (PD), and schizophrenia. The pathogenesis of PD and schizophrenia involves the interplay of mitochondrial defect and DA metabolism abnormalities. This article focuses on this issue in schizophrenia. It started with the introduction of metabolism, behavioral action, and physiology of DA, followed by reviewing evidence for malfunctions of dopaminergic signaling in patients with schizophrenia. Then it provided an overview of multiple facets of mitochondrial physiology before summarizing mitochondrial defects reported in clinical studies with schizophrenia patients. Finally, it discussed the interplay between DA metabolism abnormalities and mitochondrial defects and outlined some clinical studies showing effects of combination therapy of antipsychotics and antioxidants in treating patients with schizophrenia. The update and integration of these lines of information may advance our understanding of the etiology, pathogenesis, phenomenology, and treatment of schizophrenia.

A bioinformatic inquiry of the EAAT2 interactome in postmortem and neuropsychiatric datasets

Altered expression and localization of the glutamate transporter EAAT2 is found in schizophrenia and other neuropsychiatric (major depression, MDD) and neurological disorders (amyotrophic lateral sclerosis, ALS). However, the EAAT2 interactome, the network of proteins that physically or functionally interact with EAAT2 to support its activity, has yet to be characterized in severe mental illness. We compiled a list of "core" EAAT2 interacting proteins. Using Kaleidoscope, an R-shiny application, we data mined publically available postmortem transcriptome datasets to determine whether components of the EAAT2 interactome are differentially expressed in schizophrenia and, using Reactome, identify which interactome-associated biological pathways are altered. Overall, these "look up" studies highlight region-specific, primarily frontal cortex (dorsolateral prefrontal cortex and anterior cingulate cortex), changes in the EAAT2 interactome and implicate altered metabolism pathways in schizophrenia. Pathway analyses also suggest that perturbation of components of the EAAT2 interactome in animal models of antipsychotic administration impact metabolism. Similar changes in metabolism pathways are seen in ALS, in addition to altered expression of many components of the EAAT2 interactome. However, although EAAT2 expression is altered in a postmortem MDD dataset, few other components of the EAAT2 interactome are changed. Thus, "look up" studies suggest region- and disease-relevant biological pathways related to the EAAT2 interactome that implicate glutamate reuptake perturbations in schizophrenia, while providing a useful tool to exploit "omics" datasets.

Role of interaction of mGlu2 and 5-HT2A receptors in antipsychotic effects

The serotonergic and glutamatergic neurotransmitter systems have been implicated in the pathophysiology of schizophrenia, and increasing evidence shows that they interact functionally. Of note, the G_q/11-coupled serotonin 5-HT_2A (5-HT_2A) and the G_i/o-coupled metabotropic glutamate type 2 (mGlu2) receptors have been demonstrated to assemble into a functional heteromeric complex that modulates the function of each individual receptor. For conformation of the heteromeric complex, corresponding transmembrane-4 segment of 5-HT_2A and mGlu2 are required. The 5-HT_2A/mGlu2 heteromeric complex is necessary for the activation of G_q/11 proteins and for the subsequent increase in the levels of the intracellular messenger Ca²⁺. Furthermore, signaling via the heteromeric complex is dysregulated in the post-mortem brains of patients with schizophrenia, and could be linked to altered cortical function. From a behavioral perspective, this complex contributes to the hallucinatory and antipsychotic behaviors associated with 5-HT_2A and mGlu2/3 agonists, respectively. Synaptic and epigenetic mechanisms have also been found to be significantly associated with the mGlu2/5-HT_2A heteromeric complex. This review summarizes the role of crosstalk between mGlu2 and 5-HT_2A in the mechanism of antipsychotic effects and introduces recent key advancements on this topic.