Olanzapine's effects on hypothalamic transcriptomics and kinase activity

Olanzapine is a second-generation antipsychotic that disrupts metabolism and is associated with an increased risk of type 2 diabetes. The hypothalamus is a key region in the control of whole-body metabolic homeostasis. The objective of the current study was to determine how acute peripheral olanzapine administration affects transcription and serine/threonine kinase activity in the hypothalamus. Hypothalamus samples from rats were collected following the pancreatic euglycemic clamp, thereby allowing us to study endpoints under steady state conditions for plasma glucose and insulin. Olanzapine stimulated pathways associated with inflammation, but diminished pathways associated with the capacity to combat endoplasmic reticulum stress and G protein-coupled receptor activity. These pathways represent potential targets to reduce the incidence of type 2 diabetes in patients taking antipsychotics.

Neurocognitive correlates of metabolic dysregulation in individuals with mood disorders: a systematic review and meta-analysis

Individuals with mood disorders are predisposed to metabolic dysfunction, while those with metabolic dysregulation such as diabetes and obesity experience more severe depressive symptoms. Both metabolic dysfunction and mood disorders are independently associated with cognitive deficits. Therefore, given their close association, this study aimed to explore the association between metabolic dysfunction in individuals with mood disorders in relation to cognitive outcomes. A comprehensive search comprised of these three domains was carried out; a random-effects meta-analysis pooling mean cognitive outcomes was conducted (PROSPERO ID: CRD42022295765). Sixty-three studies were included in this review; 26 were synthesized in a quantitative meta-analysis. Comorbid metabolic dysregulation was associated with significantly lower global cognition among individuals with mood disorders. These trends were significant within each mood disorder subgroup, including major depressive disorder, bipolar disorder, and self-report depression/depressive symptoms. Type 2 diabetes was associated with the lowest cognitive performance in individuals with mood disorders, followed by peripheral insulin resistance, body mass index ⩾25 kg/m2, and metabolic syndrome. Significant reduction in scores was also observed among individual cognitive domains (in descending order) of working memory, attention, executive function, processing speed, verbal memory, and visual memory. These findings demonstrate the detrimental effects of comorbid metabolic dysfunction in individuals with mood disorders. Further research is required to understand the underlying mechanisms connecting mood disorders, metabolism, and cognition.

Safety of BEN guidelines in clozapine treatment: A Canadian perspective

OBJECTIVE

Unidentified benign ethnic neutropenia (BEN) has been recognized as a factor contributing to clozapine underutilization and discontinuation. Guidelines were implemented to accommodate BEN in Canada, and our main objective was to evaluate clozapine's safety in a sample of Canadian psychiatric patients with BEN.

METHOD

A retrospective chart review was conducted at the Centre for Addiction and Mental Health, Toronto, Canada. Through the clozapine clinic registry, participants were identified who (i) received clozapine using the approved BEN guidelines for hematological monitoring, and (ii) had at least one complete blood count pre- and post-clozapine initiation.

RESULTS

Our sample population was comprised of 41 BEN patients who were African-Caribbean (49 %), African (34 %), African-North American (12 %), Middle Eastern (2 %), and Indian-Caribbean (2 %). There was a significant reduction in hematological alerts for these patients while monitored under BEN guidelines (p < 0.001). The mean within-patient ANC value was not significantly different one year after clozapine initiation compared to the pre-clozapine baseline (p = 0.069). None of the patients discontinued clozapine for hematological reasons.

CONCLUSIONS

Findings demonstrated that patients monitored under the modified hematological guidelines for BEN can be safely treated with clozapine. These findings have important clinical ramifications as increased implementation of BEN guidelines may allow for broader use of clozapine.

Glucose dysregulation in antipsychotic-naive first-episode psychosis: in silico exploration of gene expression signatures

Antipsychotic (AP)-naive first-episode psychosis (FEP) patients display early dysglycemia, including insulin resistance and prediabetes. Metabolic dysregulation may therefore be intrinsic to psychosis spectrum disorders (PSDs), independent of the metabolic effects of APs. However, the potential biological pathways that overlap between PSDs and dysglycemic states remain to be identified. Using meta-analytic approaches of transcriptomic datasets, we investigated whether AP-naive FEP patients share overlapping gene expression signatures with non-psychiatrically ill early dysglycemia individuals. We meta-analyzed peripheral transcriptomic datasets of AP-naive FEP patients and non-psychiatrically ill early dysglycemia subjects to identify common gene expression signatures. Common signatures underwent pathway enrichment analysis and were then used to identify potential new pharmacological compounds via Integrative Library of Integrated Network-Based Cellular Signatures (iLINCS). Our search results yielded 5 AP-naive FEP studies and 4 early dysglycemia studies which met inclusion criteria. We discovered that AP-naive FEP and non-psychiatrically ill subjects exhibiting early dysglycemia shared 221 common signatures, which were enriched for pathways related to endoplasmic reticulum stress and abnormal brain energetics. Nine FDA-approved drugs were identified as potential drug treatments, of which the antidiabetic metformin, the first-line treatment for type 2 diabetes, has evidence to attenuate metabolic dysfunction in PSDs. Taken together, our findings support shared gene expression changes and biological pathways associating PSDs with dysglycemic disorders. These data suggest that the pathobiology of PSDs overlaps and potentially contributes to dysglycemia. Finally, we find that metformin may be a potential treatment for early metabolic dysfunction intrinsic to PSDs.

Depression in caregivers of patients with schizophrenia: a scoping review

PURPOSE

Caregivers play a vitally important role in the lives of people with schizophrenia. However, their mental health can often be overlooked. In recent years, with increasing attention to mental health and wellness, common mental illness such as depression in caregivers of people with schizophrenia has received renewed attention. The purpose of this review was to consolidate and synthesize recent literature on (1) the prevalence of depression in caregivers of people with schizophrenia, (2) factors associated with depression in caregivers of people with schizophrenia, and (3) interventions that target depression in caregivers of people with schizophrenia.

METHODS

A systematic search focusing on literature published between 2010 and 2022 was done to retrieve relevant articles from the following databases: Ovid MEDLINE, Ovid EMBASE, and Ovid Psych INFO.

RESULTS

Twenty-four studies met inclusion criteria and were included in the review. Nine evaluated the prevalence of depression, 18 evaluated factors associated with depression in caregivers, and 6 examined interventions targeting depression. The prevalence of depression and depressive symptoms in samples of caregivers ranged between 12 and 40% across the studies. Females, especially mothers of people with schizophrenia, were more likely to experience depression, followed by younger caregivers. Several factors, including gender, interpersonal relationships, social support, stigma, literacy, and financial constraints, were identified as factors associated with depression in caregivers. Several interventions like yoga, emotional training, and psychoeducation were evaluated, and they showed a significant reduction in the level of depression and depressive symptoms experienced by the caregiver population.

CONCLUSIONS

Depression in caregivers in this clinical population may be widespread and warrants further study. There are promising interventions that can target depression in caregivers. Well-designed longitudinal studies may help identify caregivers at risk of developing depression and further inform targets for intervention.

Central insulin dysregulation in antipsychotic-naïve first-episode psychosis: In silico exploration of gene expression signatures

Antipsychotic drug (AP)-naïve first-episode psychosis (FEP) patients display premorbid cognitive dysfunctions and dysglycemia. Brain insulin resistance may link metabolic and cognitive disorders in humans. This suggests that central insulin dysregulation represents a component of the pathophysiology of psychosis spectrum disorders (PSDs). Nonetheless, the links between central insulin dysregulation, dysglycemia, and cognitive deficits in PSDs are poorly understood. We investigated whether AP-naïve FEP patients share overlapping brain gene expression signatures with central insulin perturbation (CIP) in rodent models. We systematically compiled and meta-analyzed peripheral transcriptomic datasets of AP-naïve FEP patients along with hypothalamic and hippocampal datasets of CIP rodent models to identify common transcriptomic signatures. The common signatures were used for pathway analysis and to identify potential drug treatments with discordant (reverse) signatures. AP-naïve FEP and CIP (hypothalamus and hippocampus) shared 111 and 346 common signatures respectively, which were associated with pathways related to inflammation, endoplasmic reticulum stress, and neuroplasticity. Twenty-two potential drug treatments were identified, including antidiabetic agents. The pathobiology of PSDs may include central insulin dysregulation, which contribute to dysglycemia and cognitive dysfunction independently of AP treatment. The identified treatments may be tested in early psychosis patients to determine if dysglycemia and cognitive deficits can be mitigated.

Management of dyslipidaemia in individuals with severe mental illness: a population-based study in the Greater Copenhagen Area

Background

Severe mental illness (SMI) is associated with increased cardiovascular risk. Dyslipidaemia is a potentially modifiable risk factor, which may be inadequately managed in patients with SMI.

Objectives

To assess management of dyslipidaemia in patients with SMI versus healthy controls (HCs) in 2005 and 2015.

Design and methods

Using Danish registers, we identified adult patients with SMI in the Greater Copenhagen Area (schizophrenia spectrum disorders or bipolar disorder) with ⩾1 general practitioner contact in the year before 2005 and 2015, respectively, and HCs without SMI matched on age and gender (1:5). Outcomes were lipid-profile measurements, presence of dyslipidaemia and redemption of lipid-lowering pharmacotherapy. Differences in outcomes between patients with SMI and controls were measured with multivariable logistic regression.

Results

We identified 7217 patients with SMI in 2005 and 9939 in 2015. After 10 years, patients went from having lower odds of lipid measurements to having higher odds of lipid measurements compared with HCs [odds ratio (OR)2005 0.70 (99% confidence interval (CI) 0.63-0.78) versus OR2015 1.34 (99% CI 1.24-1.44); p2005versus2015 < 0.01]. Patients had higher odds of dyslipidaemia during both years [OR2005 1.43 (99% CI 1.10-1.85) and OR2015 1.23 (99% CI 1.08-1.41)]. Patients went from having lower odds of receiving lipid-lowering pharmacotherapy to having higher odds of receiving lipid-lowering pharmacotherapy [OR2005 0.77 (99% CI 0.66-0.89) versus OR2015 1.37 (99% CI 1.24-1.51); p2005versus2015 < 0.01]. However, among persons at high cardiovascular risk, patients had lower odds of receiving lipid-lowering pharmacotherapy during both years, including subsets with previous acute coronary syndrome [OR2005 0.30 (99% CI 0.15-0.59) and OR2015 0.44 (99% CI 0.24-0.83)] and ischaemic stroke or transient ischaemic attack (TIA) [OR2005 0.43 (99% CI 0.26-0.69) and OR 2015 0.61 (99% CI 0.41-0.89)].

Conclusion

These results imply an increased general awareness of managing dyslipidaemia among patients with SMI in the primary prophylaxis of cardiovascular disease. However, secondary prevention with lipid-lowering drugs in patients with SMI at high cardiovascular risk may be lacking.

Antipsychotic-Induced Weight Gain in Severe Mental Illness: Risk Factors and Special Considerations

PURPOSE OF REVIEW

Weight gain is a disconcerting issue experienced by patients treated with antipsychotics (APs). This review summarizes current knowledge on the prevalence, etiology, and risk factors for antipsychotic-induced weight gain (AIWG), and evidence for interventions, including special considerations.

RECENT FINDINGS

Predisposing risk factors for AIWG include lack of prior AP exposure, sex, and age. AP dose and duration of exposure are additional treatment-related factors that may contribute to this issue. Among current approaches to target AIWG, metformin has the most evidence to support its use, and this is increasingly reflected in clinical guidelines. While lifestyle approaches are recommended, cost-effectiveness and scalability represent limitations. More research is needed to identify newer treatment options and inform clinical recommendations for AIWG. Concerns around scope of practice in psychiatry to address AIWG and related comorbidities will require enhanced training opportunities and interdisciplinary collaborations, as well as updated position statements/practice guidelines emphasizing prevention.

Clinical improvement in schizophrenia during antipsychotic treatment in relation to changes in glucose parameters: A systematic review

Antipsychotics (APs) are the cornerstone of treatment for schizophrenia (SCZ) spectrum disorders. Previous research suggests that there may be a positive association between AP-induced weight gain and/or dyslipidemia and improvement in psychiatric symptoms, often referred to as a "metabolic threshold". To determine whether a similar relationship exists for glucose parameters, we conducted a systematic search in six databases from inception to June 2022 for all longitudinal studies that directly examined the relationship between changes in glucose-related outcomes and changes in psychopathology among patients with SCZ treated with APs. We identified 10 relevant studies and one additional study that considered cognition. In most cases, we found that increased levels of fasting glucose and insulin following treatment were associated with clinical improvement. These findings contribute to existing literature that could suggest a common mechanism between AP action and metabolic side effects and support a need for additional work aimed at exploring the validity of a glucose-psychopathology relation in SCZ.

Characterization and prediction of individual functional outcome trajectories in schizophrenia spectrum disorders (PREDICTS study): Study protocol

Schizophrenia spectrum disorders (SSDs) are associated with significant functional impairments, disability, and low rates of personal recovery, along with tremendous economic costs linked primarily to lost productivity and premature mortality. Efforts to delineate the contributors to disability in SSDs have highlighted prominent roles for a diverse range of symptoms, physical health conditions, substance use disorders, neurobiological changes, and social factors. These findings have provided valuable advances in knowledge and helped define broad patterns of illness and outcomes across SSDs. Unsurprisingly, there have also been conflicting findings for many of these determinants that reflect the heterogeneous population of individuals with SSDs and the challenges of conceptualizing and treating SSDs as a unitary categorical construct. Presently it is not possible to identify the functional course on an individual level that would enable a personalized approach to treatment to alter the individual's functional trajectory and mitigate the ensuing disability they would otherwise experience. To address this ongoing challenge, this study aims to conduct a longitudinal multimodal investigation of a large cohort of individuals with SSDs in order to establish discrete trajectories of personal recovery, disability, and community functioning, as well as the antecedents and predictors of these trajectories. This investigation will also provide the foundation for the co-design and testing of personalized interventions that alter these functional trajectories and improve outcomes for people with SSDs.

Promising translatable pharmacological interventions for body weight management in individuals with severe mental illness - a narrative review

INTRODUCTION

Psychotropic medications, especially antipsychotics, have been consistently shown to cause weight gain in individuals with severe mental illness (SMI), a population inherently challenged by poor physical health. Consequently, compared to the general population, this contributes to an increased cardiometabolic burden, including the risk of type 2 diabetes, dyslipidemia, and hypertension. Furthermore, comorbid obesity leads to treatment nonadherence, decreased quality of life, and increased risk of relapse, posing a challenge in the management of mental health. To address this, emerging agents investigated in the general population with potential to mitigate weight gain were explored to assess translatability to the SMI population.

AREAS COVERED

A literature search was conducted including agents approved for the management of obesity in the general population, along with upcoming agents under investigation in phase III trials with weight loss properties.

EXPERT OPINION

Metformin and topiramate along with lifestyle interventions are commonly prescribed for weight gain in individuals with SMI; however, their weight loss potential is modest at best. This review identified tirzepatide and cagrilintide-semaglutide among others as promising agents for adjunctive pharmacological management of weight gain.

Outcomes and clinical implications of intranasal insulin on cognition in humans: A systematic review and meta-analysis

BACKGROUND

Aberrant brain insulin signaling has been posited to lie at the crossroads of several metabolic and cognitive disorders. Intranasal insulin (INI) is a non-invasive approach that allows investigation and modulation of insulin signaling in the brain while limiting peripheral side effects.

OBJECTIVES

The objective of this systematic review and meta-analysis is to evaluate the effects of INI on cognition in diverse patient populations and healthy individuals.

METHODS

MEDLINE, EMBASE, PsycINFO, and Cochrane CENTRAL were systematically searched from 2000 to July 2021. Eligible studies were randomized controlled trials that studied the effects of INI on cognition. Two independent reviewers determined study eligibility and extracted relevant descriptive and outcome data.

RESULTS

Twenty-nine studies (pooled N = 1,726) in healthy individuals as well as those with Alzheimer's disease (AD)/mild cognitive impairment (MCI), mental health disorders, metabolic disorders, among others, were included in the quantitative meta-analysis. Patients with AD/MCI treated with INI were more likely to show an improvement in global cognition (SMD = 0.22, 95% CI: 0.05-0.38 p = <0.00001, N = 12 studies). Among studies with healthy individuals and other patient populations, no significant effects of INI were found for global cognition.

CONCLUSIONS

This review demonstrates that INI may be associated with pro-cognitive benefits for global cognition, specifically for individuals with AD/MCI. Further studies are required to better understand the neurobiological mechanisms and differences in etiology to dissect the intrinsic and extrinsic factors contributing to the treatment response of INI.

Pharmacological Interventions for the Prevention of Antipsychotic-Induced Weight Gain in People With Schizophrenia: A Cochrane Systematic Review and Meta-Analysis

Patients with schizophrenia are burdened by higher rates of obesity, cardiovascular disease and reduced life expectancy than the general population. In addition to illness, genetic and lifestyle factors, the associated weight gain and metabolic adverse effects of antipsychotic (AP) medications are known to exacerbate and accelerate these cardiometabolic problems significantly. Given the detrimental consequences of weight gain and other metabolic disturbances, there is an urgent need for safe and effective strategies to manage these issues as early on as possible. This review summarizes the literature of adjunctive pharmacological interventions aimed at preventing AP-induced weight gain.

Antipsychotic-Induced Alterations in Lipid Turnover

Schizophrenia is a debilitating psychiatric disorder that is treated with antipsychotics. However, despite their efficacy, antipsychotics increase the risk of metabolic disorders in a population that suffers from premature cardiovascular death. Published reports to date strongly suggest that antipsychotic-induced alterations in lipid metabolism are part of the causal relationship between antipsychotic treatment and both metabolic and cardiovascular disease. Notably, some of the adverse effects of antipsychotics on lipid metabolism are independent of antipsychotic-induced weight gain. Moreover, some antipsychotics also have beneficial effects on certain aspects of lipid metabolism. In this review, we summarize the current knowledge regarding how antipsychotics modulate lipid turnover at the whole-body, tissue, and cellular levels. We also highlight gaps in the literature, especially with respect to the intracellular mechanisms through which antipsychotics affect lipid metabolism.

Technology-Enabled Collaborative Care for Concurrent Diabetes and Distress Management During the COVID-19 Pandemic: Protocol for a Mixed Methods Feasibility Study

BACKGROUND

The COVID-19 pandemic disrupted the delivery of diabetes care and worsened mental health among many patients with type 2 diabetes (T2D). This disruption puts patients with T2D at risk for poor diabetes outcomes, especially those who experience social disadvantage due to socioeconomic class, rurality, or ethnicity. The appropriate use of communication technology could reduce these gaps in diabetes care created by the pandemic and also provide support for psychological distress.

OBJECTIVE

The purpose of this study is to test the feasibility of an innovative co-designed Technology-Enabled Collaborative Care (TECC) model for diabetes management and mental health support among adults with T2D.

METHODS

We will recruit 30 adults with T2D residing in Ontario, Canada, to participate in our sequential explanatory mixed methods study. They will participate in 8 weekly web-based health coaching sessions with a registered nurse, who is a certified diabetes educator, who will be supported by a digital care team (ie, a peer mentor, an addictions specialist, a dietitian, a psychiatrist, and a psychotherapist). Assessments will be completed at baseline, 4 weeks, and 8 weeks, with a 12-week follow-up. Our primary outcome is the feasibility and acceptability of the intervention, as evident by the participant recruitment and retention rates. Key secondary outcomes include assessment completion and delivery of the intervention. Exploratory outcomes consist of changes in mental health, substance use, and physical health behaviors. Stakeholder experience and satisfaction will be explored through a qualitative descriptive study using one-on-one interviews.

RESULTS

This paper describes the protocol of the study. The recruitment commenced in June 2021. This study was registered on October 29, 2020, on ClinicalTrials.gov (Registry ID: NCT04607915). As of June 2022, all participants have been recruited. It is anticipated that data analysis will be complete by the end of 2022, with study findings available by the end of 2023.

CONCLUSIONS

The development of an innovative, technology-enabled model will provide necessary support for individuals living with T2D and mental health challenges. This TECC program will determine the feasibility of TECC for patients with T2D and mental health issues.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04607915; https://clinicaltrials.gov/ct2/show/NCT04607915.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/39724.

Metabolomic signatures associated with weight gain and psychosis spectrum diagnoses: A pilot study

Psychosis spectrum disorders (PSDs), as well as other severe mental illnesses where psychotic features may be present, like bipolar disorder, are associated with intrinsic metabolic abnormalities. Antipsychotics (APs), the cornerstone of treatment for PSDs, incur additional metabolic adversities including weight gain. Currently, major gaps exist in understanding psychosis illness biomarkers, as well as risk factors and mechanisms for AP-induced weight gain. Metabolomic profiles may identify biomarkers and provide insight into the mechanistic underpinnings of PSDs and antipsychotic-induced weight gain. In this 12-week prospective naturalistic study, we compared serum metabolomic profiles of 25 cases within approximately 1 week of starting an AP to 6 healthy controls at baseline to examine biomarkers of intrinsic metabolic dysfunction in PSDs. In 17 of the case participants with baseline and week 12 samples, we then examined changes in metabolomic profiles over 12 weeks of AP treatment to identify metabolites that may associate with AP-induced weight gain. In the cohort with pre-post data (n = 17), we also compared baseline metabolomes of participants who gained ≥5% baseline body weight to those who gained <5% to identify potential biomarkers of antipsychotic-induced weight gain. Minimally AP-exposed cases were distinguished from controls by six fatty acids when compared at baseline, namely reduced levels of palmitoleic acid, lauric acid, and heneicosylic acid, as well as elevated levels of behenic acid, arachidonic acid, and myristoleic acid (FDR < 0.05). Baseline levels of the fatty acid adrenic acid was increased in 11 individuals who experienced a clinically significant body weight gain (≥5%) following 12 weeks of AP exposure as compared to those who did not (FDR = 0.0408). Fatty acids may represent illness biomarkers of PSDs and early predictors of AP-induced weight gain. The findings may hold important clinical implications for early identification of individuals who could benefit from prevention strategies to reduce future cardiometabolic risk, and may lead to novel, targeted treatments to counteract metabolic dysfunction in PSDs.

Semaglutide for the treatment of antipsychotic-associated weight gain in patients not responding to metformin - a case series

Metformin is the currently accepted first-line treatment for antipsychotic-associated weight gain (AAWG). However, not all patients benefit from metformin. Glucagon-like peptide-1 receptor agonists (GLP1-RA) have shown promise in the management of obesity in the general population, with preliminary evidence supporting efficacy in AAWG. Semaglutide is a weekly injectable GLP-1RA which received recent approval for obesity management and noted superiority over other GLP-1RAs. This study explored the efficacy and tolerability of semaglutide in AAWG among individuals with severe mental illness. A retrospective chart review of patients treated with semaglutide in the Metabolic Clinic at the Center for Addiction and Mental Health (CAMH) between 2019 and 2021 was conducted. Patients failing a trial of metformin (<5% weight loss or continuing to meet criteria for metabolic syndrome) after 3 months at the maximum tolerated dose (1500-2000 mg/day) were initiated on semaglutide up to 2 mg/week. The primary outcome measure was a change in weight at 3, 6, and 12 months. Twelve patients on weekly semaglutide injections of 0.71 ± 0.47 mg/week were included in the analysis. About 50% were female; the average age was 36.09 ± 13.32 years. At baseline, mean weight was 111.4 ± 31.7 kg, BMI was 36.7 ± 8.2 kg/m², with a mean waist circumference of 118.1 ± 19.3 cm. A weight loss of 4.56 ± 3.15 kg (p < 0.001), 5.16 ± 6.27 kg (p = 0.04) and 8.67 ± 9 kg (p = 0.04) was seen at 3, 6, and 12 months, respectively, after initiation of semaglutide with relatively well-tolerated side-effects. Initial evidence from our real-world clinical setting suggests that semaglutide may be effective in reducing AAWG in patients not responding to metformin. Randomized control trials investigating semaglutide for AAWG are needed to corroborate these findings.

Pharmacological interventions for prevention of weight gain in people with schizophrenia

BACKGROUND

Antipsychotic-induced weight gain is an extremely common problem in people with schizophrenia and is associated with increased morbidity and mortality. Adjunctive pharmacological interventions may be necessary to help manage antipsychotic-induced weight gain. This review splits and updates a previous Cochrane Review that focused on both pharmacological and behavioural approaches to this problem.

OBJECTIVES

To determine the effectiveness of pharmacological interventions for preventing antipsychotic-induced weight gain in people with schizophrenia.

SEARCH METHODS

The Cochrane Schizophrenia Information Specialist searched Cochrane Schizophrenia's Register of Trials on 10 February 2021. There are no language, date, document type, or publication status limitations for inclusion of records in the register.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that examined any adjunctive pharmacological intervention for preventing weight gain in people with schizophrenia or schizophrenia-like illnesses who use antipsychotic medications.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed the quality of included studies. For continuous outcomes, we combined mean differences (MD) in endpoint and change data in the analysis. For dichotomous outcomes, we calculated risk ratios (RR). We assessed risk of bias for included studies and used GRADE to judge certainty of evidence and create summary of findings tables. The primary outcomes for this review were clinically important change in weight, clinically important change in body mass index (BMI), leaving the study early, compliance with treatment, and frequency of nausea. The included studies rarely reported these outcomes, so, post hoc, we added two new outcomes, average endpoint/change in weight and average endpoint/change in BMI.

MAIN RESULTS

Seventeen RCTs, with a total of 1388 participants, met the inclusion criteria for the review. Five studies investigated metformin, three topiramate, three H2 antagonists, three monoamine modulators, and one each investigated monoamine modulators plus betahistine, melatonin and samidorphan. The comparator in all studies was placebo or no treatment (i.e. standard care alone). We synthesised all studies in a quantitative meta-analysis. Most studies inadequately reported their methods of allocation concealment and blinding of participants and personnel. The resulting risk of bias and often small sample sizes limited the overall certainty of the evidence. Only one reboxetine study reported the primary outcome, number of participants with clinically important change in weight. Fewer people in the treatment condition experienced weight gains of more than 5% and more than 7% of their bodyweight than those in the placebo group (> 5% weight gain RR 0.27, 95% confidence interval (CI) 0.11 to 0.65; 1 study, 43 participants; > 7% weight gain RR 0.24, 95% CI 0.07 to 0.83; 1 study, 43 participants; very low-certainty evidence). No studies reported the primary outcomes, 'clinically important change in BMI', or 'compliance with treatment'. However, several studies reported 'average endpoint/change in body weight' or 'average endpoint/change in BMI'. Metformin may be effective in preventing weight gain (MD -4.03 kg, 95% CI -5.78 to -2.28; 4 studies, 131 participants; low-certainty evidence); and BMI increase (MD -1.63 kg/m2, 95% CI -2.96 to -0.29; 5 studies, 227 participants; low-certainty evidence). Other agents that may be slightly effective in preventing weight gain include H2 antagonists such as nizatidine, famotidine and ranitidine (MD -1.32 kg, 95% CI -2.09 to -0.56; 3 studies, 248 participants; low-certainty evidence) and monoamine modulators such as reboxetine and fluoxetine (weight: MD -1.89 kg, 95% CI -3.31 to -0.47; 3 studies, 103 participants; low-certainty evidence; BMI: MD -0.66 kg/m2, 95% CI -1.05 to -0.26; 3 studies, 103 participants; low-certainty evidence). Topiramate did not appear effective in preventing weight gain (MD -4.82 kg, 95% CI -9.99 to 0.35; 3 studies, 168 participants; very low-certainty evidence). For all agents, there was no difference between groups in terms of individuals leaving the study or reports of nausea. However, the results of these outcomes are uncertain given the very low-certainty evidence.

AUTHORS' CONCLUSIONS

There is low-certainty evidence to suggest that metformin may be effective in preventing weight gain. Interpretation of this result and those for other agents, is limited by the small number of studies, small sample size, and short study duration. In future, we need studies that are adequately powered and with longer treatment durations to further evaluate the efficacy and safety of interventions for managing weight gain.

The metabolic adverse effects of antipsychotic use in individuals with intellectual and/or developmental disability: A systematic review and meta-analysis

OBJECTIVE

Individuals with intellectual and/or developmental disability (IDD) are often prescribed antipsychotics (APs). However, despite their known propensity to cause metabolic adverse effects, including weight gain, diabetes, and increased risk of cardiovascular events, there is currently a limited body of literature describing the metabolic consequences of AP use in this population.

METHODS

We searched MEDLINE, EMBASE, PsychINFO, CENTRAL, and CINAHL databases to identify all randomized trials that reported on the metabolic effects of APs in individuals with IDD. Random effects meta-analyses were used to examine weight gain as both a continuous and dichotomous outcome.

RESULTS

Eighteen randomized trials met our inclusion criteria with a total of 1376 patients across a variety of IDDs. AP use was associated with significantly greater weight gain compared with placebo (Continuous: mean difference = 1.10 kg, [0.79, 1.40], p < 0.00001, I²  = 54%; Dichotomous: odds ratio = 3.94, [2.15, 7.23], p < 0.00001, I²  = 0). Sub-group analysis revealed no significant effect of AP type. Data regarding the effects of APs on other metabolic outcomes were limited.

CONCLUSION

This review (PROSPERO # CRD42021255558) demonstrates that AP use is associated with significant weight gain among patients with IDD. Concerningly, most reported studies were in children and adolescents, which sets up an already vulnerable population for adverse medical sequalae at an early age. There was also a lack of long-term studies in adults with IDD. Further studies are required to better understand how AP use affects metabolic parameters in this group of individuals.

Metformin for the prevention of clozapine-induced weight gain: A retrospective naturalistic cohort study

OBJECTIVE

Clozapine is presently the sole antipsychotic with an indication for treatment-resistant Schizophrenia, but is associated with significant weight gain and other metabolic aberrations. This retrospective chart review aimed to evaluate the effectiveness of adjunctive metformin in preventing clozapine-induced weight gain.

METHODS

We conducted a retrospective chart review of patients newly initiated on clozapine at the Centre for Addiction and Mental Health in Canada, from November 2014 to April 2021. Our primary outcome was body weight at 6 and 12 months after clozapine initiation. Other metabolic parameters served as secondary outcomes.

RESULTS

Among 396 patients (males: 71.5%, mean age: 42.8 years) initiated on clozapine, 69 were on metformin or prescribed it ≤3 months after clozapine initiation. The clozapine+metformin group demonstrated less weight gain compared with the clozapine-only group at 6 months (clozapine+metformin: -0.15 kg [SE = 1.08] vs. clozapine-only: 2.99 kg, SE = 0.54) and 12 months after clozapine initiation (clozapine+metformin: -0.67 kg, SE = 1.22 vs. clozapine-only: 4.72 kg, SE = 0.67). Adaptive changes were also observed for fasting glucose (F = 3.10, p = 0.046) and triglycerides (F = 8.56, p < 0.001) in the clozapine+metformin group compared with clozapine only.

CONCLUSION

In this large retrospective naturalistic cohort study, co-prescription of clozapine and metformin was associated with less weight gain and related metabolic dysfunction at 6 and 12 months after initiation versus clozapine alone. These findings provide evidence for the effectiveness of metformin in preventing clozapine-induced weight gain; larger randomized controlled trials are needed to confirm these results.

Non-invasive neuromodulation of dorsolateral prefrontal cortex to reduce craving in alcohol use disorder: A meta-analysis

Introduction

While several pharmacological and behavioral treatments are available for alcohol use disorder (AUD), they may not be effective for all patients. The aim of this systematic review and meta-analysis was to evaluate the efficacy and safety of rTMS and tDCS for craving in AUD.

Methods

EMBASE, Cochrane Library, PsycINFO, and PubMed databases were searched for original, peer-reviewed research articles in the English language published between January 2000 and January 2022. Randomized controlled trials (RCTs) reporting changes in alcohol craving among patients with AUD were selected. Random-effects meta-analysis was employed to pool data.

Results

Changes in alcohol craving were extracted from 15 RCTs. Six studies assessed the efficacy of rTMS while nine studies examined tDCS. Results demonstrated that in comparison to sham stimulation, active rTMS to the DLPFC yields small but significant reductions in alcohol craving (standardized mean difference [SMD] = -0.27, p = .03). However, DLPFC stimulation via tDCS was not superior to sham stimulation in producing changes in alcohol craving (SMD = -0.08, p = .59).

Conclusions

Our meta-analysis suggests that rTMS may be superior to tDCS in reducing alcohol craving in patients with AUD. However, additional research is needed to identify optimal stimulation parameters for both non-invasive neuromodulatory techniques in AUD.

Emotion Processing Deficit in Euthymic Bipolar Disorder: A Potential Endophenotype

BACKGROUND

Emotion processing deficits have been described in patients with bipolar disorder (BD) and are considered one of the core cognitive abnormalities in BD with endophenotype potential. However, the literature on specific impairments in emotion processing cognitive strategies (directive/cortical/higher versus intuitive/limbic/lower) in euthymic adult BD patients and healthy first-degree relatives/high-risk (HR) subjects in comparison with healthy controls (HCs) is sparse.

METHODS

We examined facial emotion recognition deficits (FERD) in BD (N = 30), HR (N = 21), and HC (N = 30) matched for age (years), years of education, and sex using computer-administered face emotions-Matching And Labeling Task (eMALT).

RESULTS

The three groups were significantly different based on labeling accuracy scores for fear and anger (FA) (P < 0.001) and sad and disgust (SD) (P < 0.001). On post-hoc analysis, HR subjects exhibited a significant deficit in the labeling accuracy of FA facial emotions (P < 0.001) compared to HC. The BD group was found to have significant differences in all FA (P = 0.004) and SD (P = 0.003) emotion matching as well as FA (P = 0.001) and SD (P < 0.001) emotion labeling accuracy scores.

CONCLUSIONS

BD in remission exhibits FERD in general, whereas specific labeling deficits of fear and anger emotions, indicating impaired directive higher order aspect of emotion processing, were demonstrated in HR subjects. This appears to be a potential endophenotype. These deficits could underlie the pathogenesis in BD, with possible frontolimbic circuitry impairment. They may have potential implications in functional recovery and prognosis of BD.

Metabolic adverse effects of off-label use of second-generation antipsychotics in the adult population: a systematic review and meta-analysis

Prescription rates of second-generation antipsychotics (SGAs) are rapidly increasing for non-indicated (i.e., off-label) usage. SGAs used for approved indications are associated with significant metabolic adverse effects, including weight gain. The objective of this systematic review and meta-analysis is to evaluate the metabolic adverse effects of SGA use for off-label management of psychiatric illnesses in the adult population. We performed a systematic database search to identify randomized controlled trials (RCTs) that reported on weight and other metabolic outcomes with off-label use of SGAs among adults. Thirty-eight RCTs met inclusion criteria for this review; 35 of these studies, with a total of 4930 patients, were included in the quantitative meta-analysis. Patients treated with olanzapine, risperidone, and quetiapine were more likely to report weight gain as a side effect and experience clinically significant (≥7%) weight gain compared to those treated with a placebo. Among studies that reported weight as a continuous outcome, olanzapine was associated with significantly greater weight gain across all disorders (mean difference (MD) = 3.24 kg, 95% CI: 2.57-3.90 p = 0.001, N = 12 studies). Similar trends were noted with quetiapine and risperidone. A meta-regression analysis revealed a positive dose-response association between olanzapine dose and weight gain (regression coefficient: 0.36, p = 0.001). This review demonstrates that off-label use of SGAs, and particularly olanzapine, is associated with significant weight gain among adult patients. Our findings are concerning given the widespread off-label use of SGAs. Further studies are required to better understand the effects of off-label SGA use on other metabolic parameters. The study was registered with the PROSPERO international database of prospectively registered systematic reviews (PROSPERO #143186).

Gut microbiome in schizophrenia and antipsychotic-induced metabolic alterations: a scoping review

Schizophrenia (SCZ) is a severe mental disorder with high morbidity and lifetime disability rates. Patients with SCZ have a higher risk of developing metabolic comorbidities such as obesity and diabetes mellitus, leading to increased mortality. Antipsychotics (APs), which are the mainstay in the treatment of SCZ, increase the risk of these metabolic perturbations. Despite extensive research, the mechanism underlying SCZ pathophysiology and associated metabolic comorbidities remains unclear. In recent years, gut microbiota (GMB) has been regarded as a 'chamber of secrets', particularly in the context of severe mental illnesses such as SCZ, depression, and bipolar disorder. In this scoping review, we aimed to investigate the underlying role of GMB in the pathophysiology of SCZ and metabolic alterations associated with APs. Furthermore, we also explored the therapeutic benefits of prebiotic and probiotic formulations in managing SCZ and AP-induced metabolic alterations. A systematic literature search yielded 46 studies from both preclinical and clinical settings that met inclusion criteria for qualitative synthesis. Preliminary evidence from preclinical and clinical studies indicates that GMB composition changes are associated with SCZ pathogenesis and AP-induced metabolic perturbations. Fecal microbiota transplantation from SCZ patients to mice has been shown to induce SCZ-like behavioral phenotypes, further supporting the plausible role of GMB in SCZ pathogenesis. This scoping review recapitulates the preclinical and clinical evidence suggesting the role of GMB in SCZ symptomatology and metabolic adverse effects associated with APs. Moreover, this scoping review also discusses the therapeutic potentials of prebiotic/probiotic formulations in improving SCZ symptoms and attenuating metabolic alterations related to APs.

Trait Anhedonia in Schizophrenia: A Systematic Review and Comparative Meta-analysis

Anhedonia, the reduced capacity to experience pleasure, has long been considered a prominent feature of schizophrenia spectrum disorders. Many domain-specific conceptualizations of anhedonia and pleasure capacity have been developed, and there currently exist a variety of self-report assessment tools that purport to assess these various domains. The current systematic review and meta-analysis (PROSPERO: CRD42020156169) aimed to quantify overall and domain-specific self-reported anhedonia in people with schizophrenia compared to nonpsychiatric controls. We performed a literature search of PsycINFO, MEDLINE, and Embase databases for dissertations and peer-reviewed articles published in English prior to June 2021. Studies employing a psychometrically validated self-report measure of anhedonia, pleasure experience or affect in people with schizophrenia, schizoaffective, or schizophreniform disorders; studies utilizing at least one clearly defined healthy or community control group for comparison; and studies providing sufficient data to calculate effect sizes were included in this review. Random and mixed effects meta-analyses, meta-regressions, and subgroup comparisons were run across domains of anhedonia to explore weighted mean effect sizes and their associated moderators. In total, 146 studies met inclusion criteria, yielding 390 Hedges' g effect sizes from the included comparisons. People with schizophrenia reported moderate-to-large elevations in overall and domain-specific anhedonia. A sensitivity analysis accounting for high risk of bias studies did not significantly impact results. Lastly, patient sex, education, negative symptom severity, antipsychotic class, and trait negative affect differentially moderated effect sizes across domains of anhedonia. Despite the heterogeneity inherent in schizophrenia spectrum disorders, self-reported anhedonia is ubiquitously reported across self-report measures in this population.

Adiposity in schizophrenia: A systematic review and meta-analysis

OBJECTIVE

Although a relationship between schizophrenia (SCZ), antipsychotic (AP) medication, and metabolic dysregulation is now well established, the effect of adiposity is less well understood. By synthesizing findings from imaging techniques that measure adiposity, our systematic review and meta-analysis (PROSPERO CRD42020192977) aims to determine the adiposity-related effects of illness and treatment in this patient population.

METHODS

We searched MEDLINE, EMBASE, PsychINFO and Scopus for all relevant case-control and prospective longitudinal studies from inception until February 2021. Measures of adiposity including percent body fat (%BF), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) were analyzed as primary outcomes.

RESULTS

Our search identified 29 articles that used imaging methods to quantify adiposity among patients with SCZ spectrum disorders. Analyses revealed that patients have greater %BF (mean difference (MD) = 3.09%; 95% CI: 0.75-5.44), SAT (MD = 24.29 cm² ; 95% CI: 2.97-45.61) and VAT (MD = 33.73 cm² , 95% CI: 4.19-63.27) compared to healthy controls. AP treatment was found to increase SAT (MD = 31.98 cm² ; 95% CI: 11.33-52.64) and VAT (MD = 16.30 cm² ; 95% CI: 8.17-24.44) with no effect on %BF. However, change in %BF was higher for AP-free/AP-naïve patients compared to treated patients.

CONCLUSION

Our findings indicate that patients with SCZ spectrum disorders have greater adiposity than healthy controls, which is increased by AP treatment. Young, AP-naïve patients may be particularly susceptible to this effect. Future studies should explore the effect of specific APs on adiposity and its relation to overall metabolic health.

Schizophrenia: Antipsychotics and drug development

The introduction of chlorpromazine and the work that ensued provided the foundation to reposition schizophrenia as a biological illness. The present paper follows the evolution of antipsychotics and their shift from 'typical' to 'atypical'. Atypicality is reviewed in reference to its original definition, clozapine's role, and developments that now leave the concept's utility in question. In a similar fashion, drug development is reviewed in the context of the illness' multiple symptom domains, as well as differences captured by clinical staging and phenotyping. Collectively, the evidence argues for a more nuanced approach to drug development that aligns with the illness' heterogeneity and complexity. Just as 'atypical' as a descriptor for antipsychotics may be outdated, it may be time to set aside the notion of developing drugs that treat 'schizophrenia'.

Autonomic nervous system dysfunction in schizophrenia: impact on cognitive and metabolic health

Schizophrenia (SCZ) is a psychiatric disorder characterized by a wide range of positive, negative and cognitive symptoms, along with an increased risk of metabolic syndrome and cardiovascular disease that contribute to a 15-20-year reduced life expectancy. Autonomic dysfunction, in the form of increased sympathetic activity and decreased parasympathetic activity, is postulated to be implicated in SCZ and its treatment. The aim of this narrative review is to view SCZ through an autonomic lens and synthesize the evidence relating autonomic dysfunction to different domains of SCZ. Using various methods of assessing autonomic activity, autonomic dysfunction was found to be associated with multiple aspects of SCZ pathophysiology, including symptom severity, cognitive impairment, and the development of cardiometabolic comorbidities, such as metabolic syndrome and high BMI. The strongest association of low heart rate variability was noted among patients on antipsychotic treatment with high-affinity muscarinic antagonism (i.e., clozapine, olanzapine and quetiapine). The review will also suggest ways in which studying autonomic dysfunction can help reduce morbidity and mortality associated with SCZ and its treatment.

Roles of inflammation in intrinsic pathophysiology and antipsychotic drug-induced metabolic disturbances of schizophrenia

Schizophrenia is a debilitating psychiatric illness that remains poorly understood. While the bulk of symptomatology has classically been associated with disrupted brain functioning, accumulating evidence demonstrates that schizophrenia is characterized by systemic inflammation and disturbances in metabolism. Indeed, metabolic disease is a major determinant of the high mortality rate associated with schizophrenia. Antipsychotic drugs (APDs) have revolutionized management of psychosis, making it possible to rapidly control psychotic symptoms. This has ultimately reduced relapse rates of psychotic episodes and improved overall quality of life for people with schizophrenia. However, long-term APD use has also been associated with significant metabolic disturbances including weight gain, dysglycemia, and worsening of the underlying cardiometabolic disease intrinsic to schizophrenia. While the mechanisms for these intrinsic and medication-induced metabolic effects remain unclear, inflammation appears to play a key role. Here, we review the evidence for roles of inflammatory mechanisms in the disease features of schizophrenia and how these mechanisms interact with APD treatment. We also discuss the effects of common inflammatory mediators on metabolic disease. Then, we review the evidence of intrinsic and APD-mediated effects on systemic inflammation in schizophrenia. Finally, we speculate about possible treatment strategies. Developing an improved understanding of inflammatory processes in schizophrenia may therefore introduce new, more effective options for treating not only schizophrenia but also primary metabolic disorders.

Antisaccade task performance in obsessive-compulsive disorder and its clinical correlates

OBJECTIVE

Obsessive-Compulsive Disorder (OCD) is characterized by abnormalities in the cortico-striato-thalamo-cortical (CSTC) circuitry of the brain. Antisaccade eye movement tasks measure aspects of the voluntary control of behaviour that are sensitive to CSTC circuitry dysfunction.

METHOD

In this study, we examined antisaccade eye movement parameters of OCD patients in comparison with healthy controls (HC). In addition, we also examined the relationship between the antisaccade eye movement parameters and the severity of OCD. Antisaccade performance among right handed OCD patients (N = 65) was compared to matched right handed HC (N = 57). Eye tracking data during the task performance were collected using an Eye-Link eye-tracker at 1000-Hz sampling rate. OCD symptom severity was evaluated using Yale-Brown obsessive compulsive scale.

RESULTS

The antisaccade error percentage was significantly greater in OCD patients than HC (p < 0.001). In addition, OCD patients had less accurate final eye position compared to HC (p < 0.001). There were no significant correlation between antisaccade parameters and OCD severity measures.

CONCLUSION

Deficient performance in antisaccade task supports CSTC abnormality in OCD and this appears to be independent of the illness severity. Examining this in remitted participants with OCD and in unaffected first degree relatives could help ascertaining their endophenotype validity.

Associations between plasma clozapine/N-desmethylclozapine ratio, insulin resistance and cognitive performance in patients with co-morbid obesity and ultra-treatment resistant schizophrenia

Clozapine (CLZ), the sole antipsychotic with superior efficacy for ultra-treatment resistant schizophrenia (TRS), is limited by adverse effects, including metabolic dysregulation. Clozapine's main metabolite, N-desmethylclozapine (NDMC), has potent 5-HT2C antagonist properties which may explain this metabolic dysfunction, thus the CLZ:NDMC ratio is of particular interest. High insulin resistance states could be associated with CYP1A2 induction and lower CLZ:NDMC ratios. Additionally, lower CLZ:NDMC ratios have been associated with better cognitive, but worse metabolic functioning. This study investigated associations between metabolic and cognitive parameters with the CLZ/NDMC ratio. Primary outcomes included relationships between the CLZ:NDMC ratio to the homeostatic model assessment for insulin resistance (HOMA-IR) and Brief Assessment of Cognition in Schizophrenia (BACS) composite z-scores. Secondary outcomes assessed relationships between CLZ:NDMC ratios to fasting insulin, BMI, weight, fasting glucose, and BACS digit sequencing z-scores. 38 patients who were overweight or obese with schizophrenia or schizoaffective disorder completed fasting bloodwork, anthropometric, psychopathological, and cognitive assessments. Multivariate regressions found a statistically significant inverse association between the CLZ/NDMC ratio and HOMA-IR (B = - 1.028, SE B = .473, β = - 0.348 p = 0.037), which may have been driven by fasting insulin levels (B = - 27.124, SE B = 12.081, β = - 0.351 p = 0.031). The CLZ/NDMC ratio may predict insulin resistance/metabolic comorbidity among patients with TRS receiving clozapine.

Pharmacological Interventions to Treat Antipsychotic-Induced Dyslipidemia in Schizophrenia Patients: A Systematic Review and Meta Analysis

Introduction: Antipsychotic-induced dyslipidemia represents a common adverse effect faced by patients with schizophrenia that increases risk for developing further metabolic complications and cardiovascular disease. Despite its burden, antipsychotic-induced dyslipidemia is often left untreated, and the effectiveness of pharmacological interventions for mitigating dyslipidemia has not been well-addressed. This review aims to assess the effectiveness of pharmacological interventions in alleviating dyslipidemia in patients with schizophrenia. Methods: Medline, PsychInfo, and EMBASE were searched for all relevant English articles from 1950 to November 2020. Randomized placebo-controlled trials were included. Differences in changes in triglycerides, HDL cholesterol, LDL cholesterol, and VLDL cholesterol levels between treatment and placebo groups were meta-analyzed as primary outcomes. Results: Our review identified 48 randomized controlled trials that comprised a total of 3,128 patients and investigated 29 pharmacological interventions. Overall, pharmacological interventions were effective in lowering LDL cholesterol, triglycerides, and total cholesterol levels while increasing the levels of HDL cholesterol. Within the intervention subgroups, approved lipid-lowering agents did not reduce lipid parameters other than total cholesterol level, while antipsychotic switching and antipsychotic add-on interventions improved multiple lipid parameters, including triglycerides, LDL cholesterol, HDL cholesterol, and total cholesterol. Off label lipid lowering agents improved triglycerides and total cholesterol levels, with statistically significant changes seen with metformin. Conclusion: Currently available lipid lowering agents may not work as well in patients with schizophrenia who are being treated with antipsychotics. Additionally, antipsychotic switching, antipsychotic add-ons, and certain off label interventions might be more effective in improving some but not all associated lipid parameters. Future studies should explore novel interventions for effectively managing antipsychotic-induced dyslipidemia. Registration: PROSPERO 2020 CRD42020219982; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020219982.

Exploring Patterns of Disturbed Eating in Psychosis: A Scoping Review

Disturbed eating behaviours have been widely reported in psychotic disorders since the early 19th century. There is also evidence that antipsychotic (AP) treatment may induce binge eating or other related compulsive eating behaviours. It is therefore possible that abnormal eating patterns may contribute to the significant weight gain and other metabolic disturbances observed in patients with psychosis. In this scoping review, we aimed to explore the underlying psychopathological and neurobiological mechanisms of disrupted eating behaviours in psychosis spectrum disorders and the role of APs in this relationship. A systematic search identified 35 studies that met our eligibility criteria and were included in our qualitative synthesis. Synthesizing evidence from self-report questionnaires and food surveys, we found that patients with psychosis exhibit increased appetite and craving for fatty food, as well as increased caloric intake and snacking, which may be associated with increased disinhibition. Limited evidence from neuroimaging studies suggested that AP-naïve first episode patients exhibit similar neural processing of food to healthy controls, while chronic AP exposure may lead to decreased activity in satiety areas and increased activity in areas associated with reward anticipation. Overall, this review supports the notion that AP use can lead to disturbed eating patterns in patients, which may contribute to AP-induced weight gain. However, intrinsic illness-related effects on eating behaviors remain less well elucidated, and many confounding factors as well as variability in study designs limits interpretation of existing literature in this field and precludes firm conclusions from being made.

Impact of NRG1 HapICE gene variants on digit ratio and dermatoglyphic measures in schizophrenia

Multiple lines of evidence have suggested a potential role of Neuregulin-1 (NRG1) in the neurodevelopmental pathogenesis of schizophrenia. Interaction between genetic risk variants present within NRG1 locus and non-specific gestational putative insults can significantly impair crucial processes of brain development. Such genetic effects can be analyzed through the assessment of digit ratio and dermatoglyphic patterns. We examined the role of two well-replicated polymorphisms of NRG1 (SNP8NRG221533 and SNP8NRG243177) on schizophrenia risk and its probable impact on the digit ratio and dermatoglyphic measures in patients (N = 221) and healthy controls (N = 200). In schizophrenia patients, but not in healthy controls, a significant association between NRG1 SNP8NRG221533 C/C genotype with lower left 2D:4D ratio, as well as with higher FA_T_bcRC and DA_T_bcRC. The substantial effect of SNP8NRG221533 on both digit ratio and dermatoglyphic measures suggest a potential role for NRG1 gene variants on neurodevelopmental pathogenesis of schizophrenia.

Investigation of the Gut Microbiome in Patients with Schizophrenia and Clozapine-Induced Weight Gain: Protocol and Clinical Characteristics of First Patient Cohorts

BACKGROUND

Emerging evidence suggests an important role of the human gut microbiome in psychiatry and neurodevelopmental disorders. An increasing body of literature based on animal studies has reported that the gut microbiome influences brain development and behavior by interacting with the gut-brain axis. Furthermore, as the gut microbiome has an important role in metabolism and is known to interact with pharmaceuticals, recent evidence suggests a role for the microbiome in antipsychotic-induced metabolic side effects in animals and humans.

PURPOSE

Here we present the protocol for a two-phase study investigating the gut microbiome in healthy controls and in patients with schizophrenia treated with antipsychotics.

METHODS

Phase I of our study involves humans exclusively. We recruit 25 patients who are chronically treated with clozapine and compare them with 25 healthy controls matched for age, sex, BMI, and smoking status. A second cohort consists of 25 patients newly starting on clozapine, and a third cohort includes 25 antipsychotic-naive patients. The patients in the second cohort and third cohort are prospectively assessed for up to 6 and 12 weeks, respectively. Phase II of this study will incorporate microbiota humanized mouse models to examine the influence of human fecal transplant on metabolic parameters and the gut-brain axis. Progress and Future Directions: We are underway with the first participants enrolled in all phase I treatment cohorts. This study will contribute to elucidating the role of the gut microbiome in schizophrenia and metabolic side effects. In addition, its results may help to explore potential therapeutic targets for antipsychotic-induced metabolic side effects.

Leukocyte mitochondrial DNA copy number in schizophrenia

OBJECTIVE

Schizophrenia is a complex neuropsychiatric disorder with significant genetic predisposition. In a subset of schizophrenia patients, mitochondrial dysfunction could be explained by the genomic defects like mitochondrial DNA Copy Number Variations, which are considered as a sensitive index of cellular oxidative stress. Given the high energy demands for neuronal functions, altered Mitochondrial DNA copy number (mtDNAcn) and consequent impaired mitochondrial physiology would significantly influence schizophrenia pathogenesis. In this context, we have made an attempt to study mitochondrial dysfunction in schizophrenia by assessing mtDNAcn in antipsychotic-naïve/free schizophrenia patients.

METHOD

mtDNAcn was measured in 90 antipsychotic-naïve / free schizophrenia (SCZ) patients and 147 Healthy Controls (HC). The relative mtDNAcn was determined by quantitative real-time polymerase chain reaction (qPCR) using TaqMan® multiplex assay method.

RESULT

A statistically significant difference between groups [t = 5.22, P < 0.001] was observed, with significantly lower mtDNAcn in SCZ compared to HC. The group differences persisted even after controlling for age and sex [F (4, 232) = 22.68, P < 0.001, η2 = 0.09].

CONCLUSION

Lower mtDNAcn in SCZ compared to HC suggests that mtDNAcn may hold potential to serve as an important proxy marker of mitochondrial function in antipsychotic-naïve/free SCZ patients.

Physical health among people with serious mental illness in the face of COVID-19: Concerns and mitigation strategies

COVID-19 can worsen the physical health of individuals with serious mental illness, a vulnerable group already facing physical health disparities. COVID-19 is further reducing access to physical health care due to shutdown of services deemed "non-urgent" and overcrowding of emergency services. Management of chronic diseases, highly prevalent in this group, is undermined due to exacerbation of psychiatric disorders, reduction in availability of social support, and worsening of negative social determinants of health. In this commentary, we discuss the challenges experienced by this group and offer mitigation strategies to reduce: (1) inequalities in access to physical health care; and (2) disruptions to the management of chronic physical conditions in the face of COVID-19. Recommendations include coordinated efforts by health authorities, primary and mental health care organizations, researchers, policymakers, and other stakeholders. These efforts should ensure equitable access to physical health care and implementation of innovative programs to protect the physical health of people with serious mental illness during and following the pandemic.

Working memory performance with online-tDCS in schizophrenia: A randomized, double-blinded, sham-controlled, partial cross-over proof-of-concept study

Combining cognitive retraining with transcranial direct current stimulation (tDCS) has been hypothesized to improve cognitive deficits in schizophrenia. The effect of combining a neuropsychological/psychophysiological task with tDCS, called "online-tDCS" for cognitive enhancement in schizophrenia is not rigorously assessed. In this proof-of-concept study, we aimed at evaluating the effect of a single session online-tDCS on working memory(WM) and its transferability to other cognitive functions. Numerical n-back(NNB), digit symbol substitution test(DSST), emotional matching and labelling test(E-MALT), and anti-saccade eye movement beeforefore and after 20 min tDCS (anode: left dorsolateral prefrontal cortex and cathode: left temporoparietal junction) applied during Sternberg's task(WM-task) were assessed. Twenty-three schizophrenia patients with cognitive deficits were randomized to receive either online-tDCS or offline-tDCS (without simultaneous Sternberg's task) sessions. All patients received one session each of active and sham tDCS in a randomized counterbalanced double-blind cross-over design. RMANOVA revealed a significant interaction effect between tDCS type (Online/Offline) x activeness (active/sham) of tDCS; the reaction time during 2-back performance in the NNB test improved in online-sham (F = 5.23, p < 0.038) but not online-active tDCS session. No significant changes were noted in DSST, E-MALT, and anti-saccade performance. Improved performance after online-sham tDCS suggests that performing the Sternberg's task enhanced 2-back performance. The counterintuitive observation was noted with respect to the non-enhancement of WM performance on combining the task to tDCS. Aberrant plasticity in schizophrenia might attain a transitional ceiling that would have resulted in restriction of enhancement on combining the two plasticity modulators. The transferability of improvement to other cognitive domains could not be ascertained.

Tolerance of transcranial direct current stimulation in psychiatric disorders: An analysis of 2000+ sessions

Transcranial direct current stimulation (tDCS), a non-invasive, neuromodulatory technique, is being increasingly applied to several psychiatric disorders. In this study, we describe the side-effect profile of repeated tDCS sessions (N = 2005) that were administered to 171 patients (156 adults and 15 adolescents) with different psychiatric disorders [schizophrenia [N = 109], obsessive-compulsive disorder [N = 28], alcohol dependence syndrome [N = 13], mild cognitive impairment [N = 10], depression [N = 6], dementia [N = 2] and other disorders [N = 3]]. tDCS was administered at a constant current strength of 2 mA with additional ramp-up and ramp-down phase of 20 s each at the beginning and end of the session, respectively. Other tDCS protocol parameters were: schizophrenia and obsessive-compulsive disorder: 5-days of twice-daily 20-min sessions with an inter-session interval of 3-h; Mild cognitive impairment/dementia and alcohol dependence syndrome: at least 5-days of once-daily 20-min session; Depression: 10-days of once-daily 30 min session. At the end of each tDCS session, any adverse event observed by the administrator and/or reported by the patient was systematically assessed using a comprehensive questionnaire. The commonly reported adverse events during tDCS included burning sensations (16.2%), skin redness (12.3%), scalp pain (10.1%), itching (6.7%), and tingling (6.3%). Most of the adverse events were noted to be mild, transient and well-tolerated. In summary, our observations suggest that tDCS is a safe mode for therapeutic non-invasive neuromodulation in psychiatric disorders in adults as well as the adolescent population.

The clozapine to norclozapine ratio: a narrative review of the clinical utility to minimize metabolic risk and enhance clozapine efficacy

Introduction: Clozapine remains the most effective antipsychotic for treatment-refractory schizophrenia. However, ~40% of the patients respond insufficiently to clozapine. Clozapine's effects, both beneficial and adverse, have been proposed to be partially attributable to its main metabolite, N-desmethylclozapine (NDMC). However, the relation of the clozapine to norclozapine ratio (CLZ:NDMC; optimally defined as ~2) to clinical response and metabolic outcomes is not clear.Areas covered: This narrative review comprehensively examines the clinical utility of the CLZ:NDMC ratio to reduce metabolic risk and increase treatment efficacy. The association of the CLZ:NDMC ratio with changes in psychopathology, cognitive functioning, and cardiometabolic burden will be explored, as well as adjunctive treatments and their effects.Expert opinion: The literature suggests a positive association between the CLZ:NDMC ratio and better cardiometabolic outcomes. Conversely, the CLZ:NDMC ratio appears inversely associated with better cognitive functioning but less consistently with other psychiatric domains. The CLZ:NDMC ratio may be useful for predicting and monitoring cardiometabolic adverse effects and optimizing potential cognitive benefits of clozapine. Future studies are required to replicate these findings, which if substantiated, would encourage examination of adjunctive treatments aiming to alter the CLZ:NDMC ratio to best meet the needs of the individual patient, thereby broadening clozapine's clinical utility.

Brain insulin action: Implications for the treatment of schizophrenia

Insulin action in the central nervous system is a major regulator of energy balance and cognitive processes. The development of central insulin resistance is associated with alterations in dopaminergic reward systems and homeostatic signals affecting food intake, glucose metabolism, body weight and cognitive performance. Emerging evidence has highlighted a role for antipsychotics (APs) to modulate central insulin-mediated pathways. Although APs remain the cornerstone treatment for schizophrenia they are associated with severe metabolic complications and fail to address premorbid cognitive deficits, which characterize the disorder of schizophrenia. In this review, we first explore how the hypothesized association between schizophrenia and CNS insulin dysregulation aligns with the use of APs. We then investigate the proposed relationship between CNS insulin action and AP-mediated effects on metabolic homeostasis, and different domains of psychopathology, including cognition. We briefly discuss a potential role of CNS insulin signaling to explain the hypothesized, but somewhat controversial association between therapeutic efficacy and metabolic side effects of APs. Finally, we propose how this knowledge might inform novel treatment strategies to target difficult to treat domains of schizophrenia. This article is part of the issue entitled 'Special Issue on Antipsychotics'.

Brain insulin action in schizophrenia: Something borrowed and something new

Insulin signaling in the central nervous system is at the intersection of brain and body interactions, and represents a fundamental link between metabolic and cognitive disorders. Abnormalities in brain insulin action could underlie the development of comorbid schizophrenia and type 2 diabetes. Among its functions, central nervous system insulin is involved in regulation of striatal dopamine levels, peripheral glucose homeostasis, and feeding regulation. In this review, we discuss the role and importance of central nervous system insulin in schizophrenia and diabetes pathogenesis from a historical and mechanistic perspective. We describe central nervous system insulin sites and pathways of action, with special emphasis on glucose metabolism, cognitive functioning, inflammation, and food preferences. Finally, we suggest possible mechanisms that may explain the actions of central nervous system insulin in relation to schizophrenia and diabetes, focusing on glutamate and dopamine signaling, intracellular signal transduction pathways, and brain energetics. Understanding the interplay between central nervous system insulin and schizophrenia is essential to disentangling this comorbid relationship and may provide novel treatment approaches for both neuropsychiatric and metabolic dysfunction. This article is part of the issue entitled 'Special Issue on Antipsychotics'.