Treatment-resistant schizophrenia: current insights on the pharmacogenomics of antipsychotics

CYP-catalysed cycling of clozapine and clozapine-N-oxide promotes the generation of reactive oxygen species in vitro

Clozapine is an effective atypical antipsychotic indicated for treatment-resistant schizophrenia, but is under-prescribed due to the risk of severe adverse drug reactions such as myocarditis.A mechanistic understanding of clozapine cardiotoxicity remains elusive.This study aimed to investigate the contribution of selected CYP isoforms to cycling between clozapine and its major circulating metabolites, N-desmethylclozapine and clozapine-N-oxide, with the potential for reactive species production.CYP supersome™-based in vitro techniques were utilised to quantify specific enzyme activity associated with clozapine, clozapine-N-oxide and N-desmethylclozapine metabolism.The formation of reactive species within each incubation were quantified, and known intermediates detected.CYP3A4 predominately catalysed clozapine-N-oxide formation from clozapine and was associated with concentration-dependent reactive species production, whereas isoforms favouring the N-desmethylclozapine pathway (CYP2C19 and CYP1A2) did not produce reactive species.Extrahepatic isoforms CYP2J2 and CYP1B1 were also associated with the formation of clozapine-N-oxide and N-desmethylclozapine but did not favour one metabolic pathway over another.Unique to this investigation is that various CYP isoforms catalyse clozapine-N-oxide reduction to clozapine.This process was associated with the concentration-dependent formation of reactive species with CYP3A4, CYP1B1 and CYP1A1 that did not correlate with known reactive intermediates, implicating metabolite cycling and reactive oxygen species in the mechanism of clozapine-induced toxicity.

Clozapine monitoring at a specialised psychiatric hospital: A retrospective chart review

Background

Clozapine is the only Food and Drug Administration (FDA) and National Institute for Care and Excellence (NICE) approved drug for treatment-resistant schizophrenia (TRS). Its potentially life-threatening haematological side effects of neutropaenia and agranulocytosis mandate rigorous monitoring of neutrophil counts, presenting unique, Third-World population challenges.

Aim

To describe the Clozapine white blood cell monitoring practice and outcomes in a local psychiatric hospital.

Setting

At a specialist Psychiatry unit in Durban, KwaZulu-Natal, which follows a modified algorithm of the South African Standard Treatment Guidelines for Clozapine monitoring.

Methods

A retrospective chart review composed of 120 patients on Clozapine treatment from 01 July 2018-31 December 2020. Demographic and clinical information was captured in a Redcap database. Descriptive statistics using categorical variables were used.

Results

The study population was from a low socioeconomic background, with low levels of education and employment. A baseline neutrophil count was recorded in 58 files (48.3%). Clozapine was stopped in 6 out of the 120 patients due to 'neutropaenia' (absolute neutrophil counts ranging from 1.18 to 1.6); none developed agranulocytosis. Their duration of Clozapine treatment ranged from 2 weeks-15 years.

Conclusion

Haematological monitoring frequency and documentation of patients receiving Clozapine were not in compliance with the hospital's adapted guidelines and may have resulted in the termination of treatment before true neutropaenia developed. Patients developed neutropaenia at low doses of Clozapine and after many years of treatment.

Contribution

These results suggest local Clozapine monitoring guidelines should be more strictly adhered to.

The potential role of por*28 and cyp1a2*f genetic variations and lifestyle factors on clozapine and n-desmethyl clozapine plasma levels in schizophrenia patients

BACKGROUND

Despite its advantages over other antipsychotics, for treatment-resistant schizophrenia, clinical use of Clozapine (CLZ) is challenging by its narrow therapeutic index and potentially life-threatening dose-related adverse effects.

RESEARCH DESIGN AND METHODS

As the potential role in CLZ metabolism is assigned to CYP1A2 enzyme and consequently Cytochrome P450 oxidoreductase (POR) their genetic variations might help to determine CLZ levels in schizophrenia patients. For this purpose, 112 schizophrenia patients receiving CLZ were included in the current study. Plasma CLZ and N-desmethylclozapine (DCLZ) levels were analyzed by using HPLC and genetic variations were identified with the PCR-RFLP method.

RESULTS

The patients' CYP1A2 and POR genotypes seemed to not affect plasma CLZ and DCLZ levels whereas in the subgroup analysis, POR × 28 genotype significantly influenced simple and adjusted plasma CLZ and DLCZ levels concerning smoking habit and caffeine consumption.

CONCLUSIONS

The findings of the present study highlight the importance of both genetic and non-genetic factors (smoking and caffeine consumption) for the individualization of the CLZ treatment. In addition to that, it suggests that the added utility of not only the CLZ metabolizing enzymes but also POR, which is crucial for proper CYP activity, to guide CLZ dosing might be useful for clinical decision-making.

Lost in Translation: Challenges in the Diagnosis and Treatment of Early-Onset Schizophrenia

Early-onset schizophrenia (EOS) is a heterogeneous condition that has a serious, insidious clinical course and poor long-term mental health outcomes. The clinical presentations are highly complex due to the overlapping symptomatology with other illnesses, which contributes to a delay in the diagnosis. The objective of the review is to study if an earlier age of onset (AAO) of EOS has poor clinical outcomes, the diagnostic challenges of EOS, and effective treatment strategies. The review provides a comprehensive literature search of 5966 articles and summarizes 126 selected for empirical evidence to methodically consider challenges in diagnosing and treating EOS for practicing clinicians. The risk factors of EOS are unique but have been shared with many other neuropsychiatric illnesses. Most of the risk factors, including genetics and obstetric complications, are nonmodifiable. The role of early diagnosis in reducing the duration of untreated psychosis (DUP) remains critical to reducing overall morbidity. Many specific issues contribute to the risk and clinical outcomes. Therefore, issues around diagnostic ambiguity, treatment resistance, nonadherence, and rehospitalizations further extend the DUP. There is hesitancy to initiate clozapine early, even though the empirical evidence strongly supports its use. There is a growing body of research that suggests the use of long-acting injectables to address nonadherence, and these measures are largely underutilized in acute settings. The clinical presentations of EOS are complex. In addition to the presence of specific risk factors, patients with an early onset of illness are also at a higher risk for treatment resistance. While there is a need to develop tools for early diagnosis, established evidence-based measures to address nonadherence, psychoeducation, and resistance must be incorporated into the treatment planning.

Genome-wide methylation analysis of treatment resistant schizophrenia

Various studies have investigated the relationship between genetic polymorphisms of antipsychotic drug-metabolizing agents and drug response. DNA methylation is a form of epigenetic modification that regulates gene expression. Few studies have analyzed the relationship between genome-wide methylation patterns and treatment resistance schizophrenia. The primary aim of this pilot study is to investigate the association between treatment resistance status and genome-wide DNA methylation in schizophrenia patients. Treatment resistance status was determined for 109 patients with schizophrenia. Treatment resistance was the primary outcome variable in a model, including methylation status of white blood cells using the Illumina 450 array. The genome-wide DNA methylation levels in 109 Schizophrenia subjects did not show that DNA methylation sties were associated with resistance status. From our study, it is evident the importance of continuing to investigate the relationship between DNA methylation and antipsychotic response to personalize treatment in schizophrenia. Future studies require larger prescription databases to build on the results presented in this pilot study.

Treatment resistant psychosis in children and adolescents and clozapine: Nuances

With proliferation in research on high-risk psychosis spectrum diseases, it is crucial to distinguish a prodrome or psychosis-like episode in children and adolescents from true psychosis. The limited role of psychopharmacology in such circumstances is well-documented, underlining the difficulties in diagnosing treatment resistance. To add to the confusion is emerging data on the head-to-head comparison trials for treatment-resistant and treatment-refractory schizophrenia. Clozapine, the gold-standard drug for resistant schizophrenia and other psychotic psychopathology, lacks FDA or manufacturer guidelines for use in the pediatric population. Possibly due to developmental pharmacokinetic (PK) considerations, clozapine-related side effects are more commonly seen in children than adults. Despite evidence of an increased risk for seizures and hematological problems in children, clozapine is widely used off-label. Clozapine reduces the severity of resistant childhood schizophrenia, aggression, suicidality, and severe non-psychotic illness. There is inconsistent prescribing, administration, and monitoring of clozapine, and limited database evidence-backed guidelines. Despite the overwhelming efficacy, problems remain regarding unambiguous indications of use and risk-benefits assessments. This article reviews the nuances in the diagnosis of treatment resistance psychosis in childhood and adolescents and its management, in particular highlighting the evidence base for clozapine in this population group.

The thalamus in psychosis spectrum disorder

Psychosis spectrum disorder (PSD) affects 1% of the world population and results in a lifetime of chronic disability, causing devastating personal and economic consequences. Developing new treatments for PSD remains a challenge, particularly those that target its core cognitive deficits. A key barrier to progress is the tenuous link between the basic neurobiological understanding of PSD and its clinical phenomenology. In this perspective, we focus on a key opportunity that combines innovations in non-invasive human neuroimaging with basic insights into thalamic regulation of functional cortical connectivity. The thalamus is an evolutionary conserved region that forms forebrain-wide functional loops critical for the transmission of external inputs as well as the construction and update of internal models. We discuss our perspective across four lines of evidence: First, we articulate how PSD symptomatology may arise from a faulty network organization at the macroscopic circuit level with the thalamus playing a central coordinating role. Second, we discuss how recent animal work has mechanistically clarified the properties of thalamic circuits relevant to regulating cortical dynamics and cognitive function more generally. Third, we present human neuroimaging evidence in support of thalamic alterations in PSD, and propose that a similar "thalamocortical dysconnectivity" seen in pharmacological imaging (under ketamine, LSD and THC) in healthy individuals may link this circuit phenotype to the common set of symptoms in idiopathic and drug-induced psychosis. Lastly, we synthesize animal and human work, and lay out a translational path for biomarker and therapeutic development.

Superior temporal gyrus functional connectivity predicts transcranial direct current stimulation response in Schizophrenia: A machine learning study

Transcranial direct current stimulation (tDCS) is a promising adjuvant treatment for persistent auditory verbal hallucinations (AVH) in Schizophrenia (SZ). Nonetheless, there is considerable inter-patient variability in the treatment response of AVH to tDCS in SZ. Machine-learned models have the potential to predict clinical response to tDCS in SZ. This study aims to examine the feasibility of identifying SZ patients with persistent AVH (SZ-AVH) who will respond to tDCS based on resting-state functional connectivity (rs-FC). Thirty-four SZ-AVH patients underwent resting-state functional MRI at baseline followed by add-on, twice-daily, 20-min sessions with tDCS (conventional/high-definition) for 5 days. A machine learning model was developed to identify tDCS treatment responders based on the rs-FC pattern, using the left superior temporal gyrus (LSTG) as the seed region. Functional connectivity between LSTG and brain regions involved in auditory and sensorimotor processing emerged as the important predictors of the tDCS treatment response. L1-regularized logistic regression model had an overall accuracy of 72.5% in classifying responders vs. non-responders. This model outperformed the state-of-the-art convolutional neural networks (CNN) model-both without (59.41%) and with pre-training (68.82%). It also outperformed the L1-logistic regression model trained with baseline demographic features and clinical scores of SZ patients. This study reports the first evidence that rs-fMRI-derived brain connectivity pattern can predict the clinical response of persistent AVH to add-on tDCS in SZ patients with 72.5% accuracy.

Second-Generation Antipsychotics’ Effectiveness and Tolerability: A Review of Real-World Studies in Patients with Schizophrenia and Related Disorders

Despite methodological limitations, real-world studies might support clinicians by broadening the knowledge of antipsychotics’ (APs) effectiveness and tolerability in different clinical scenarios and complement clinical trials. We conducted an extensive literature search in the PubMed database to evaluate the effectiveness and tolerability profiles of second-generation antipsychotics (SGAs) from real-world studies to aid clinicians and researchers in selecting the proper treatment for patients with schizophrenia and related disorders. The present review evidenced that SGAs demonstrated superior effectiveness over first-generation antipsychotics (FGAs) in relapse-free survival and psychiatric hospitalization rate and for treating negative symptoms. Persistence and adherence to therapy were higher in SGAs than FGAs. Most studies concluded that switching to long-acting injectables (LAIs) was significantly associated with a lower treatment failure rate than monotherapy with oral SGAs. Considerable improvements in general functionality, subjective well-being, and total score on global satisfaction tests, besides improved personal and social performance, were reported in some studies on patients treated with LAI SGAs. Clozapine was also associated with the lowest rates of treatment failure and greater effectiveness over the other SGAs, although with more severe side effects. Effectiveness on primary negative symptoms and cognitive deficits was rarely measured in these studies. Based on the data analyzed in the present review, new treatments are needed with better tolerability and improved effectiveness for negative, affective, and cognitive symptoms.

Clozapine prescribing practice and trends in Qatar: First national observational study

BACKGROUND

Clozapine is the gold standard in the management of treatment-resistant schizophrenia. Despite its clinically proven efficacy clozapine utilization is variable globally and published evidence is suggestive of its underutilization. Research from the Arab region on clozapine utilization is limited. The aim of our descriptive observational study was to evaluate the prescribing practice of clozapine and its sociodemographic and clinical corelates in the State of Qatar.

METHODS

The study is a retrospective case-note review of all patients maintained on clozapine, in the calendar year 2020. Data were collected on sociodemographic characteristics of the patients; antipsychotic trials before initiating clozapine; and clinical characteristics of the patients, including their diagnoses leading to prescription of clozapine, duration of illness, psychiatric hospitalizations, and co-morbidities.

RESULTS

During the study period, 100 patients were maintained on clozapine. Patients were mostly Qatari and non-Qatari Arab males. Prescription rates were significantly different for Qatari patients when compared to non-Qatari patients. Most patients had a chronic illness with the age of onset of illness in early adulthood and were diagnosed with schizophrenia or schizoaffective disorder. The mean daily dose of clozapine was 325 mg. Eighty percent of the patients received two or more antipsychotic trials before initiating clozapine. Sixty-eight percent of the patients had more than two antipsychotic trials before initiating Clozapine. One third of patients had no history of psychiatric hospitalizations, and one quarter had five or more previous psychiatric hospitalizations. Of the psychiatric comorbidities, mood and substance use disorders were common. Of medical comorbidities, endocrine and metabolic disorders were common.

CONCLUSION

Despite apparent underutilization, the Clozapine prescribing rates in Qatar are comparable to countries with plasma monitoring systems when framed within Qatar's unique demographic context. However, there still is a significant delay in Clozapine initiation despite its clinical superiority.

STRENGTHS AND LIMITATIONS OF THIS STUDY

First study on Clozapine utilization from the Middle-East and North-Africa region. This study examined prescribing of clozapine in a national cohort of patients in Qatar. Provides insight into sociodemographic and clinical correlates of clozapine prescribing in a country with 90% migrants. Limited by the completeness of the information contained in the patients' medical charts.

Relationships between early age at onset of psychotic symptoms and treatment resistant schizophrenia

AIM

Early age at schizophrenia onset (EOS) has been associated with a worse clinical course, although previous studies reported substantial heterogeneity. Despite the relevance of the subject, the relationship between the age of onset and treatment resistant schizophrenia (TRS) is less clear.

METHODS

We screened 197 non-affective psychotic patients. Of these, 99 suffered from schizophrenia and were putative TRS and were included in a prospective 4-to-8-week trial to assess their response to antipsychotics. According to status (TRS/nonTRS) and age-at-onset (early: ≤18 years, EOS; adult: >18 years, adult onset schizophrenia [AOS]) patients were subdivided in EOS-TRS, EOS-nonTRS, AOS-TRS, AOS-nonTRS. Multiple clinical variables were measured and compared by analysis of covariance (ANCOVA), using age as a covariate. Two-way analysis of variance (ANOVA) was used to assess whether significant differences were attributable to TRS status or age-at-onset.

RESULTS

The rate of TRS patients was significantly higher in EOS compared to AOS. At the ANCOVA, EOS-TRS had significantly worse clinical, cognitive, and psychosocial outcomes compared to the other groups. Overall, EOS-TRS were more impaired than EOS-nonTRS, while significant differences with AOS-TRS were less consistent, albeit appreciable. Two-way ANOVA demonstrated that, in the majority of the investigated variables, the significant differences among groups were attributable to the TRS status effect rather than to age-at-onset or combined effects.

CONCLUSIONS

These results suggest that refractoriness to antipsychotics may be strongly linked to the early onset of psychotic symptoms, possibly as a result of common neurobiology.

Interaction Testing and Polygenic Risk Scoring to Estimate the Association of Common Genetic Variants With Treatment Resistance in Schizophrenia

IMPORTANCE

About 20% to 30% of people with schizophrenia have psychotic symptoms that do not respond adequately to first-line antipsychotic treatment. This clinical presentation, chronic and highly disabling, is known as treatment-resistant schizophrenia (TRS). The causes of treatment resistance and their relationships with causes underlying schizophrenia are largely unknown. Adequately powered genetic studies of TRS are scarce because of the difficulty in collecting data from well-characterized TRS cohorts.

OBJECTIVE

To examine the genetic architecture of TRS through the reassessment of genetic data from schizophrenia studies and its validation in carefully ascertained clinical samples.

DESIGN, SETTING, AND PARTICIPANTS

Two case-control genome-wide association studies (GWASs) of schizophrenia were performed in which the case samples were defined as individuals with TRS (n = 10 501) and individuals with non-TRS (n = 20 325). The differences in effect sizes for allelic associations were then determined between both studies, the reasoning being such differences reflect treatment resistance instead of schizophrenia. Genotype data were retrieved from the CLOZUK and Psychiatric Genomics Consortium (PGC) schizophrenia studies. The output was validated using polygenic risk score (PRS) profiling of 2 independent schizophrenia cohorts with TRS and non-TRS: a prevalence sample with 817 individuals (Cardiff Cognition in Schizophrenia [CardiffCOGS]) and an incidence sample with 563 individuals (Genetics Workstream of the Schizophrenia Treatment Resistance and Therapeutic Advances [STRATA-G]).

MAIN OUTCOMES AND MEASURES

GWAS of treatment resistance in schizophrenia. The results of the GWAS were compared with complex polygenic traits through a genetic correlation approach and were used for PRS analysis on the independent validation cohorts using the same TRS definition.

RESULTS

The study included a total of 85 490 participants (48 635 [56.9%] male) in its GWAS stage and 1380 participants (859 [62.2%] male) in its PRS validation stage. Treatment resistance in schizophrenia emerged as a polygenic trait with detectable heritability (1% to 4%), and several traits related to intelligence and cognition were found to be genetically correlated with it (genetic correlation, 0.41-0.69). PRS analysis in the CardiffCOGS prevalence sample showed a positive association between TRS and a history of taking clozapine (r2 = 2.03%; P = .001), which was replicated in the STRATA-G incidence sample (r2 = 1.09%; P = .04).

CONCLUSIONS AND RELEVANCE

In this GWAS, common genetic variants were differentially associated with TRS, and these associations may have been obscured through the amalgamation of large GWAS samples in previous studies of broadly defined schizophrenia. Findings of this study suggest the validity of meta-analytic approaches for studies on patient outcomes, including treatment resistance.

Neuropsychological differences between treatment-resistant and treatment-responsive schizophrenia: a meta-analysis

Antipsychotic treatment resistance affects up to a third of individuals with schizophrenia. Of those affected, 70-84% are reported to be treatment resistant from the outset. This raises the possibility that the neurobiological mechanisms of treatment resistance emerge before the onset of psychosis and have a neurodevelopmental origin. Neuropsychological investigations can offer important insights into the nature, origin and pathophysiology of treatment-resistant schizophrenia (TRS), but methodological limitations in a still emergent field of research have obscured the neuropsychological discriminability of TRS. We report on the first systematic review and meta-analysis to investigate neuropsychological differences between TRS patients and treatment-responsive controls across 17 published studies (1864 participants). Five meta-analyses were performed in relation to (1) executive function, (2) general cognitive function, (3) attention, working memory and processing speed, (4) verbal memory and learning, and (5) visual-spatial memory and learning. Small-to-moderate effect sizes emerged for all domains. Similarly to previous comparisons between unselected, drug-naïve and first-episode schizophrenia samples v. healthy controls in the literature, the largest effect size was observed in verbal memory and learning [dl = -0.53; 95% confidence interval (CI) -0.29 to -0.76; z = 4.42; p < 0.001]. A sub-analysis of language-related functions, extracted from across the primary domains, yielded a comparable effect size (dl = -0.53, 95% CI -0.82 to -0.23; z = 3.45; p < 0.001). Manipulating our sampling strategy to include or exclude samples selected for clozapine response did not affect the pattern of findings. Our findings are discussed in relation to possible aetiological contributions to TRS.

Clozapine treatment and risk of severe COVID-19 infection

OBJECTIVE

To investigate whether patients with clozapine treatment are at an increased risk of a more severe COVID-19 infection as compared with patients on other antipsychotic drugs.

METHODS

In this register-based cohort study, all residents (age 18 or older) in the Stockholm Region with a psychotic disorder diagnosis and antipsychotic treatment were included (N = 8 233) and followed from 1 March 2020 to 14 January 2021. The exposure was defined as clozapine treatment and the outcome measures (indicating a more severe COVID-19 infection) were: inpatient care, care within intensive care unit or death due to COVID-19 infection. Differences in outcome rates between exposed (n = 966) and unexposed (other antipsychotics; n = 7 267) were examined using Cox proportional hazards models and expressed as hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

No statistically significant differences in outcome rates were found between the two groups of patients after adjusting for age, sex and residence in retirement homes. The adjusted HR for the exposed compared to the unexposed was 0.96 (95% CI: 0.54, 1.70) for inpatient care; 1.69 (0.48, 5.93) for care in intensive care unit (ICU); and 0.86 (0.26, 2.80) for death. Regarding inpatient care, additional adjusting for country of birth, living in socioeconomically vulnerable areas, number of care visits during the previous year, and comorbid medical illnesses did not alter the results.

CONCLUSIONS

Our results may add support to the present guidelines, recommending sustained clozapine treatment during the current COVID-19 pandemic with careful monitoring and readiness to alter drug doses as needed.

Evaluation of a collaborative care program for patients with treatment-resistant schizophrenia: Protocol for a multiple case-study. (Preprint)

Background

Approximately one-third of all patients with schizophrenia are treatment resistant. Worldwide, undertreatment with clozapine and other effective treatment options exist for people with treatment-resistant schizophrenia (TRS). In this respect, it appears that regular health care models do not optimally fit this patient group. The Collaborative Care (CC) model has proven to be effective for patients with severe mental illness, both in primary care and in specialized mental health care facilities. The key principles of the CC model are that both patients and informal caregivers are part of the treatment team, that a structured treatment plan is put in place with planned evaluations by the team, and that the treatment approach is multidisciplinary in nature and uses evidence-based interventions. We developed a tailored CC program for patients with TRS.

Objective

In this paper, we provide an overview of the research design for a potential study that seeks to gain insight into both the process of implementation and the preliminary effects of the CC program for patients with TRS. Moreover, we aim to gain insight into the experiences of professionals, patients, and informal caregivers with the program.

Methods

This study will be underpinned by a multiple case study design (N=20) that uses a mixed methods approach. These case studies will focus on an Early Psychosis Intervention Team and 2 Flexible Assertive Community treatment teams in the Netherlands. Data will be collected from patient records as well as through questionnaires, individual interviews, and focus groups. Patient recruitment commenced from October 2020.

Results

Recruitment of participants commenced from October 2020, with the aim of enrolling 20 patients over 2 years. Data collection will be completed by the end of 2023, and the results will be published once all data are available for reporting.

Conclusions

The research design, framed within the process of developing and testing innovative interventions, is discussed in line with the aims of the study. The limitations in clinical practice and specific consequences of this study are explained.

International Registered Report Identifier (IRRID)

DERR1-10.2196/35336

Cross-sectional study comparing cognitive function in treatment responsive versus treatment non-responsive schizophrenia: evidence from the STRATA study

BACKGROUND

70%-84% of individuals with antipsychotic treatment resistance show non-response from the first episode. Emerging cross-sectional evidence comparing cognitive profiles in treatment resistant schizophrenia to treatment-responsive schizophrenia has indicated that verbal memory and language functions may be more impaired in treatment resistance. We sought to confirm this finding by comparing cognitive performance between antipsychotic non-responders (NR) and responders (R) using a brief cognitive battery for schizophrenia, with a primary focus on verbal tasks compared against other measures of cognition.

DESIGN

Cross-sectional.

SETTING

This cross-sectional study recruited antipsychotic treatment R and antipsychotic NR across four UK sites. Cognitive performance was assessed using the Brief Assessment of Cognition in Schizophrenia (BACS).

PARTICIPANTS

One hundred and six participants aged 18-65 years with a diagnosis of schizophrenia or schizophreniform disorder were recruited according to their treatment response, with 52 NR and 54 R cases.

OUTCOMES

Composite and subscale scores of cognitive performance on the BACS. Group (R vs NR) differences in cognitive scores were investigated using univariable and multivariable linear regressions adjusted for age, gender and illness duration.

RESULTS

Univariable regression models observed no significant differences between R and NR groups on any measure of the BACS, including verbal memory (ß=-1.99, 95% CI -6.63 to 2.66, p=0.398) and verbal fluency (ß=1.23, 95% CI -2.46 to 4.91, p=0.510). This pattern of findings was consistent in multivariable models.

CONCLUSIONS

The lack of group difference in cognition in our sample is likely due to a lack of clinical distinction between our groups. Future investigations should aim to use machine learning methods using longitudinal first episode samples to identify responder subtypes within schizophrenia, and how cognitive factors may interact within this.

TRAIL REGISTRATION NUMBER

REC: 15/LO/0038.

Structure and stability of symptoms in first episode psychosis: a longitudinal network approach

Early psychosis is characterised by heterogeneity in illness trajectories, where outcomes remain poor for many. Understanding psychosis symptoms and their relation to illness outcomes, from a novel network perspective, may help to delineate psychopathology within early psychosis and identify pivotal targets for intervention. Using network modelling in first episode psychosis (FEP), this study aimed to identify: (a) key central and bridge symptoms most influential in symptom networks, and (b) examine the structure and stability of the networks at baseline and 12-month follow-up. Data on 1027 participants with FEP were taken from the National EDEN longitudinal study and used to create regularised partial correlation networks using the 'EBICglasso' algorithm for positive, negative, and depressive symptoms at baseline and at 12-months. Centrality and bridge estimations were computed using a permutation-based network comparison test. Depression featured as a central symptom in both the baseline and 12-month networks. Conceptual disorganisation, stereotyped thinking, along with hallucinations and suspiciousness featured as key bridge symptoms across the networks. The network comparison test revealed that the strength and bridge centralities did not differ significantly between the two networks (C = 0.096153; p = 0.22297). However, the network structure and connectedness differed significantly from baseline to follow-up (M = 0.16405, p = <0.0001; S = 0.74536, p = 0.02), with several associations between psychosis and depressive items differing significantly by 12 months. Depressive symptoms, in addition to symptoms of thought disturbance (e.g. conceptual disorganisation and stereotyped thinking), may be examples of important, under-recognized treatment targets in early psychosis, which may have the potential to lead to global symptom improvements and better recovery.

What Are the Barriers and Enablers to the Implementation of Pharmacogenetic Testing in Mental Health Care Settings?

In psychiatry, the selection of antipsychotics and antidepressants is generally led by a trial-and-error approach. The prescribing of these medications is complicated by sub-optimal efficacy and high rates of adverse drug reactions (ADRs). These both contribute to poor levels of adherence. Pharmacogenetics (PGx) considers how genetic variation can influence an individual’s response to a drug. Pharmacogenetic testing is a tool that could aid clinicians when selecting psychotropic medications, as part of a more personalized approach to prescribing. This may improve the use of and adherence to these medications. Yet to date, the implementation of PGx in mental health environments in the United Kingdom has been slow. This review aims to identify the current barriers and enablers to the implementation of PGx in psychiatry and determine how this can be applied to the uptake of PGx by NHS mental health providers. A systematic searching strategy was developed, and searches were carried out on the PsychInfo, EmBase, and PubMed databases, yielding 11 appropriate papers. Common barriers to the implementation of PGx included cost, concerns over incorporation into current workflow and a lack of knowledge about PGx; whilst frequent enablers included optimism that PGx could lead to precision medicine, reduce ADRs and become a more routine part of psychiatric clinical care. The uptake of PGx in psychiatric care settings in the NHS should consider and overcome these barriers, while looking to capitalize on the enablers identified in this review.

Structure-Based Design and Optimization of FPPQ, a Dual-Acting 5-HT3 and 5-HT6 Receptor Antagonist with Antipsychotic and Procognitive Properties

In line with recent clinical trials demonstrating that ondansetron, a 5-HT₃ receptor (5-HT₃R) antagonist, ameliorates cognitive deficits of schizophrenia and the known procognitive effects of 5-HT₆ receptor (5-HT₆R) antagonists, we applied the hybridization strategy to design dual-acting 5-HT₃/5-HT₆R antagonists. We identified the first-in-class compound FPPQ, which behaves as a 5-HT₃R antagonist and a neutral antagonist 5-HT₆R of the Gs pathway. FPPQ shows selectivity over 87 targets and decent brain penetration. Likewise, FPPQ inhibits phencyclidine (PCP)-induced hyperactivity and displays procognitive properties in the novel object recognition task. In contrast to FPPQ, neither 5-HT₆R inverse agonist SB399885 nor neutral 5-HT₆R antagonist CPPQ reversed (PCP)-induced hyperactivity. Thus, combination of 5-HT₃R antagonism and 5-HT₆R antagonism, exemplified by FPPQ, contributes to alleviating the positive-like symptoms. Present findings reveal critical structural features useful in a rational polypharmacological approach to target 5-HT₃/5-HT₆ receptors and encourage further studies on dual-acting 5-HT₃/5-HT₆R antagonists for the treatment of psychiatric disorders.

Progress in mechanistically novel treatments for schizophrenia

Currently available pharmacological treatments for schizophrenia derive their activity mainly by directly modulating the D2 receptor. This mode of action can alleviate the positive symptoms of schizophrenia but do not address the negative or cognitive symptoms of the disease and carry a heavy side effect burden that leads to high levels of patient non-compliance. Novel mechanisms to treat the positive symptoms of schizophrenia with improved tolerability, as well as medicines to treat negative and cognitive symptoms are urgently required. Recent efforts to identify small molecules for schizophrenia with non-D2 mechanisms will be highlighted, with a focus on those that have reached clinical development. Finally, the potential for disease modifying treatments for schizophrenia will also be discussed.

Therapeutic drug monitoring of clozapine in adults with schizophrenia: a review of challenges and strategies

INTRODUCTION

Clozapine (CLZ) is the superior drug in treatment of schizophrenia. Serum concentration of CLZ is associated with clinical response and dose-dependents side effects, where generalized tonic-clonic seizures are most critical. Thus, therapeutic drug monitoring (TDM) of CLZ may guide individual dosing to reach target exposure and prevent dose-dependent side effects. However, current TDM methods are not capable of predicting the risk of agranulocytosis, which is a dose-independent side effect restricting use of CLZ to treatment-resistant schizophrenia (TRS).

AREAS COVERED

The article provides an overview of clinical, pharmacological, and toxicological aspects of CLZ, and the role of TDM as a tool for dose titration and follow-up in patients with TRS. Main focus is on current challenges and strategies in CLZ TDM, including future perspectives on potential identification/analysis of CLZ metabolite biomarkers reflecting the risk of granulocyte toxicity.

EXPERT OPINION

The association between CLZ serum concentration, clinical response and risk of seizures is indisputable. TDM should therefore always guide CLZ dose titration. Development of advanced TDM methods, including biomarkers predicting the risk of granulocyte toxicity might extend TDM to be a tool for deciding which patients that can be treated safely with CLZ, potentially increasing its utility beyond TRS.

Impact cérébral structurel et fonctionnel de la Clozapine chez les patients souffrant de schizophrénie : revue systématique des études longitudinales en neuroimagerie

OBJECTIF

L'objectif de cette revue est d'identifier les corrélats anatomo-fonctionnels cérébraux lors d'un traitement par clozapine (CLZ) ainsi que les marqueurs anatomo-fonctionnels prédictifs de la réponse à la CLZ.

MÉTHODES

Nous avons réalisé une revue systématique de la littérature avec les bases de données MEDLINE et Web of Science afin d'identifier et d'examiner toutes les études longitudinales en neuroimagerie investiguant l'impact cérébral de la CLZ.

RÉSULTATS

30 études ont été incluses et analysées. La CLZ induit une diminution du volume et de la perfusion dans les noyaux gris centraux chez les patients répondeurs. Un plus grand volume de substance grise et perfusion dans ces structures avant l'instauration de la CLZ étaient associés à une meilleure réponse au traitement. La diminution de volume et de perfusion au niveau du cortex préfrontal (CPF) est observée malgré l'instauration de CLZ mais de façon moins importante chez les patients sous CLZ que chez les patients sous antipsychotiques typiques. Un plus grand volume au niveau du CPF avant l'instauration de la CLZ est associé à une meilleure réponse clinique dans la majorité des études. Enfin, la CLZ semble induire une réduction des altérations au niveau de la substance blanche.

CONCLUSION

Les corrélats anatomo-fonctionnels de la CLZ différent de ceux des autres antipsychotiques avec une action spécifique de la CLZ au niveau des ganglions de la base et du CPF pouvant participer à sa supériorité en termes de réponse clinique. Plusieurs données cliniques et d'imagerie conduisent à l'hypothèse d'un meilleur pronostic associé à une instauration plus rapide de la CLZ.

Clozapine Management in Schizophrenia Inpatients: A 5-Year Prospective Observational Study of Its Safety and Tolerability Profile

BACKGROUND

Clozapine is well known for its efficacy and clinical superiority compared to other antipsychotics in treatment-resistant schizophrenia (TRS). However, it is frequently underutilized worldwide because of its acute adverse events, as well as for its long-term cardiometabolic and hematological consequences.

OBJECTIVE

The aim of the study was to evaluate 5-year safety in chronic TRS inpatients with continuous clozapine use.

METHODS

Patients with TRS and clozapine treatment were evaluated for 5 years. All participants were assessed using the Brief Psychiatric Rating Scale (BPRS), Glasgow Antipsychotic Side-effect Scale for Clozapine (GASS-C), Social Performance Scale (PSP) and Short Portable Mental Status Questionnaire (SPMSQ). Clinical, cardiometabolic and hematological data were collected periodically. General linear models (GLM) repeated measures controlling for CLZ dose were utilized to determine differences in variables across the time.

RESULTS

Overall, 189 inpatients were screened for study participation. The final sample included twenty-one TRS patients (16 males, 76%) with an average age of 57.6 years, all with 5-year continuous use of clozapine (mean dose 266 mg/day). There was not a significant effect of time on BPRS (p=0.774), PSP (p=0.855) and SPMSQ (p=0.066); differences remained not significant after controlling for CLZ dose (p=0.585, p=0.467 and p=0.105, respectively). No changes were found in blood and clinical parameters except for red blood cell count, which decreased over time (p=0.024; η2= 0.952). Patients reported a significant BMI decrease (-8.98 kg, p=0.008) between baseline and 5 years last observation.

CONCLUSION

The findings show how the application of a structured dietary, clinical and therapeutic monitoring program in psychiatric care facilities could allow the safe and effective long-term cardiometabolic and hematological management of clozapine. The unique role that clozapine plays in the current treatment of patients with TRS requires greater clinical awareness. Although its acute and chronic side effects are notorious, its safety management is feasible and broadens its potential practical application.

Antipsychotic Polypharmacy for the Management of Schizophrenia: Evidence and Recommendations

Schizophrenia is a debilitating illness with a lifetime prevalence estimate of 0.6% and consists of symptoms from the positive, negative, and cognitive domains. Social support, therapy, psychoeducation, and overall case management are very important aspects of the treatment of schizophrenia. However, as abnormalities in neurotransmission are one of the key findings of schizophrenia pathology, pharmacotherapies are cornerstones of the management of schizophrenia. Antipsychotics have been used as the primary pharmacological treatment of schizophrenia. These agents often have a good effect on reducing positive symptoms, but may not markedly improve negative symptoms or cognitive defects. However, at least 20% of individuals with schizophrenia do not experience a substantial response from monotherapy with antipsychotics. Further, despite evolving treatment protocols and advances in early recognition of the disorder, 70% of patients with schizophrenia require long-term, even lifetime, medication to control their symptoms and do not achieve complete recovery. To address these shortcomings, clinicians and research scientists have explored different combinations of treatments, polypharmacy, to improve the treatment of patients. Antipsychotic polypharmacy has been shown to cause more side effects than monotherapy, which is the main reason why most treatment guidelines caution against it. Antipsychotic monotherapy should be strived for and clozapine should be tried at the latest if two monotherapy trials with other antipsychotics have failed and no absolute contraindications exist. If residual symptoms exist despite trials of adequate dose and duration, other reasons that may reduce treatment effect should be ruled out. Long-acting injectables or blood concentration measurements should be considered to affirm compliance and proper serum levels. Antipsychotic polypharmacy should be considered and discussed with patients from whom the aforementioned procedures do not produce a satisfactory treatment result. In some cases, antipsychotic polypharmacy may produce better results than other forms of treatment augmentation, such as benzodiazepines. In particular, combining aripiprazole with clozapine may be effective in reducing treatment side effects or residual symptoms, and this is likely to hold true for combining other partial dopamine D₂ agonists with clozapine as well, although currently scant data exist. More research is needed, both in controlled but also real-world settings, to define optimal antipsychotic polypharmacy and/or other psychotropic treatment augmentation strategies for specific patient groups and situations.

Targeting muscarinic receptors to treat schizophrenia

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

Brain stimulation effects on serum BDNF, VEGF, and TNFα in treatment-resistant psychiatric disorders

Resistance to pharmacological treatment poses a notable challenge for psychiatry. Such cases are usually treated with brain stimulation techniques, including repetitive transcranial magnetic stimulation (rTMS) and electroconvulsive therapy (ECT). Empirical evidence links treatment resistance to insufficient brain plasticity and chronic inflammation. Therefore, this study encompasses analysis of neurotrophic and inflammatory factors in psychiatric patients undergoing rTMS and ECT in order to refine the selection of patients and predict clinical outcomes. This study enrolled 25 drug-resistant depressive patients undergoing rTMS and 31 drug-resistant schizophrenia patients undergoing ECT. Clinical efficacy of brain stimulation therapies was gauged using MADRS and HAM-D scales in the depression group and PANSS scale in the schizophrenia group. Blood-derived BDNF, VEGF, and TNFα were analysed during the treatment course. For reference, 19 healthy control subjects were also enrolled. After statistical analysis, no significant differences were detected in BDNF, VEGF, and TNFα concentrations among healthy, depressive, and schizophrenic subject groups before the treatment. However, depressive patient treatment with rTMS has increased BDNF concentration, while schizophrenic patient treatment with ECT has lowered the concentration of TNFα. Our findings suggest that a lower initial TNFα concentration could be a marker for treatment success in depressed patients undergoing rTMS, whereas in schizophrenic patient group treated with ECT, a higher concentration of VEGF correlates to milder symptoms post-treatment, especially in the negative scale.

Neonatal phencyclidine and social isolation in the rat: effects of clozapine on locomotor activity, social recognition, prepulse inhibition, and executive functions deficits

RATIONALE

There is a need to develop animal models of schizophrenia-like behaviors that have both construct and predictive validity. Recently, a neonatal phencyclidine (PCP) and post-weaning social isolation dual-hit model was developed; however, its face and predictive validities need to be further investigated.

OBJECTIVE

The aims of this study were to extend the characterization of the behavioral changes occurring in the neonatal PCP and post-weaning social isolation dual-hit rat model and to evaluate the effects of chronic treatment with clozapine on signs related to schizophrenia.

METHODS

Male Wistar rat pups were treated with PCP (10 mg/kg s.c.) on postnatal days (PND) 7, 9, and 11. Starting from weaning, neonatal PCP-treated rat pups were socially isolated, while control saline-treated rats were group housed. At adulthood, rats were assessed using behavioral tasks evaluating locomotor activity, social recognition, prepulse inhibition, and reversal learning. Clozapine (3 mg/kg i.p.) was administered daily starting from a week before behavioral tests and until the end of the study.

RESULTS

Neonatal PCP-treated and post-weaning social isolated (PCP-SI) rats displayed persistent and robust locomotor hyperactivity as well as social recognition impairment. The latter could not be explained by variations in the motivation to interact with a juvenile rat. Weak-to-moderate deficits in prepulse inhibition and reversal learning were also observed. Chronic treatment with clozapine attenuated the observed locomotor hyperactivity and social recognition deficits.

CONCLUSION

The PCP-SI model presents enduring and robust deficits (hyperactivity and social recognition impairment) associated with positive symptoms and cognitive/social deficits of schizophrenia, respectively. These deficits are normalized by chronic treatment with clozapine, thereby confirming the predictive validity of this animal model.

Absolute and Dose-Adjusted Serum Concentrations of Clozapine in Patients Switching vs. Maintaining Treatment: An Observational Study of 1979 Patients

BACKGROUND

Clozapine is an effective drug for the management of schizophrenia that has not responded to other agents, but some patients experience insufficient or adverse effects and discontinue treatment.

OBJECTIVE

We investigated a potential association between clozapine serum concentrations and switching to other antipsychotics in a large real-world patient population from a therapeutic drug monitoring service.

METHODS

Absolute and dose-adjusted serum concentrations (concentration-to-dose ratios [C/D ratios]) of clozapine during dosing between 100 and 1000 mg/day were measured in 1979 Norwegian patients during the period 2005-2019. These variables were compared in patients switching to other antipsychotic drugs versus maintaining clozapine treatment using linear mixed models. Smoking habits were known for 49% of the patients. To prevent potential nonadherence affecting clozapine switching, only patients with serum concentrations above 50% of the lower reference range were included.

RESULTS

In total, 190 patients (9.6%) switched from clozapine to another antipsychotic drug during the study period, whereas the remaining patients were not detected as switchers and were interpreted as maintaining treatment. Patients switching treatment had 23.5% lower absolute concentrations (954 vs. 1245 nmol/L; p < 0.001) and 15.7% lower daily doses (305 vs. 362 mg/day; p < 0.001) of clozapine than did nonswitchers, making the clozapine C/D ratio 9.7% lower in switchers than in nonswitchers after correcting for smoking habits (2.80 vs. 3.10 nmol/L/mg/day; p = 0.032).

CONCLUSIONS

The present study suggests that decreased absolute and dose-adjusted serum concentrations of clozapine were associated with clozapine discontinuation. The significantly reduced clozapine concentrations regardless of prescribed dose in switchers versus nonswitchers may indicate a pharmacokinetic mechanism underlying the risk of clozapine discontinuation.

A Synthetic Literature Review on the Management of Emerging Treatment Resistance in First Episode Psychosis: Can We Move towards Precision Intervention and Individualised Care?

Treatment resistance is prevalent in early intervention in psychosis services, and causes a significant burden for the individual. A wide range of variables are shown to contribute to treatment resistance in first episode psychosis (FEP). Heterogeneity in illness course and the complex, multidimensional nature of the concept of recovery calls for an evidence base to better inform practice at an individual level. Current gold standard treatments, adopting a ‘one-size fits all’ approach, may not be addressing the needs of many individuals. This following review will provide an update and critical appraisal of current clinical practices and methodological approaches for understanding, identifying, and managing early treatment resistance in early psychosis. Potential new treatments along with new avenues for research will be discussed. Finally, we will discuss and critique the application and translation of machine learning approaches to aid progression in this area. The move towards ‘big data’ and machine learning holds some prospect for stratifying intervention-based subgroups of individuals. Moving forward, better recognition of early treatment resistance is needed, along with greater sophistication and precision in predicting outcomes, so that effective evidence-based treatments can be appropriately tailored to the individual. Understanding the antecedents and the early trajectory of one’s illness may also be key to understanding the factors that drive illness course.

Effectiveness of antipsychotic drugs in schizophrenia: a 10-year retrospective study in a Korean tertiary hospital

Extensive research has been carried out on the comparative effectiveness of antipsychotic medications. Most studies, however, have been performed in Western countries. The purpose of this study was to compare the effectiveness, indicated by time to any-cause discontinuation, of antipsychotic drugs in a large number of patients with schizophrenia in South Korea. We identified 1458 patients with schizophrenia or schizophreniform disorder who were treated with antipsychotic medications using a clinical data warehouse at the Seoul National University Hospital between March 2005 and February 2014. Kaplan–Meier survival analyses were used to estimate the time to discontinuation of antipsychotic drugs. We compared the survival curves of different antipsychotics using log-rank tests. Overall, the median time to discontinuation for any cause was 133 days (95% CI, 126–147). The longest time to discontinuation was observed for clozapine, followed by aripiprazole, paliperidone, olanzapine, amisulpride, risperidone, quetiapine, ziprasidone, and haloperidol. Specifically, clozapine was significantly different from all other antipsychotic drugs (all p < 0.001). Aripiprazole also had a significantly longer time to discontinuation than amisulpride (p = 0.001), risperidone (p < 0.001), quetiapine (p < 0.001), ziprasidone (p < 0.001), and haloperidol (p < 0.001). In Asian patients with schizophrenia, clozapine was the most effective antipsychotic in terms of time to discontinuation, followed by aripiprazole. This study extends the findings of previous effectiveness studies from Western populations and suggests the need to develop guidelines for the pharmacotherapy of schizophrenia tailored to Asian individuals.

Four Actionable Bottlenecks and Potential Solutions to Translating Psychiatric Genetics Research: An Expert Review

BACKGROUND

Psychiatric genetics has had limited success in translational efforts. A thorough understanding of the present state of translation in this field will be useful in the facilitation and assessment of future translational progress.

PURPOSE

A narrative literature review was conducted. Combinations of 3 groups of terms were searched in EBSCOhost, Google Scholar, and PubMed. The review occurred in multiple steps, including abstract collection, inclusion/exclusion criteria review, coding, and analysis of included papers.

RESULTS

One hundred and fourteen articles were analyzed for the narrative review. Across those, 4 bottlenecks were noted that, if addressed, may provide insights and help improve and increase translation in the field of psychiatric genetics. These 4 bottlenecks are emphasizing linear translational frameworks, relying on molecular genomic findings, prioritizing certain psychiatric disorders, and publishing more reviews than experiments.

CONCLUSIONS

These entwined bottlenecks are examined with one another. Awareness of these bottlenecks can inform stakeholders who work to translate and/or utilize psychiatric genetic information. Potential solutions include utilizing nonlinear translational frameworks as well as a wider array of psychiatric genetic information (e.g., family history and gene-environment interplay) in this area of research, expanding which psychiatric disorders are considered for translation, and when possible, conducting original research. Researchers are urged to consider how their research is translational in the context of the frameworks, genetic information, and psychiatric disorders discussed in this review. At a broader level, these efforts should be supported with translational efforts in funding and policy shifts.

Persistence of Antipsychotic Use After Clozapine Discontinuation: A Real-World Study Across Antipsychotics

Although clozapine treatment is often discontinued due to limited efficacy or low tolerability, there is a lack of guidelines and evidence on treatment options after discontinuation of clozapine in patients with schizophrenia. Persistence has proven to be an adequate indicator for treatment effectiveness in patients with schizophrenia. The aim of this study was, therefore, to compare persistence of antipsychotic use between antipsychotic treatment options in patients after stopping clozapine treatment. Registry data from a prescription database representative of the Dutch population (1996-2017) was collected to investigate persistence in patients with schizophrenia who had been using clozapine for ≥ 90 days. Persistence with antipsychotics after clozapine discontinuation was analyzed using Cox-proportional hazard regression models. Our study population consisted of 321 participants, of whom 138 re-initiated clozapine and 183 started some other antipsychotic in the year after clozapine discontinuation (N = 518 antipsychotic use periods, N = 9,178 months). Second-generation antipsychotics (SGAs) as a group were associated with better persistence compared to first-generation antipsychotics (adjusted hazard ratio (aHR), 0.73; 95% confidence interval (CI) 0.57-0.93; P = 0.011). Compared with other antipsychotics, the following oral monotherapy antipsychotics were associated with significantly better persistence: restarting clozapine (aHR 0.48; 95% CI 0.32-0.71; P < 0.001) and switching to risperidone (aHR 0.52; 95% CI 0.32-0.84; P = 0.008) or olanzapine (aHR 0.55; 95% CI 0.35-0.87; P = 0.010). Sensitivity analyses confirmed the results. In conclusion, oral SGAs are associated with better persistence than alternative antipsychotic treatment options in patients discontinuing clozapine for undefined reasons. Especially clozapine (except in those with previous serious adverse reactions to clozapine), olanzapine and risperidone should be considered as oral monotherapy for these patients.

Anti-Stress Properties of Atypical Antipsychotics

Stress exposure represents a major environmental risk factor for schizophrenia and other psychiatric disorders, as it plays a pivotal role in the etiology as well as in the manifestation of disease symptomatology. It may be inferred that pharmacological treatments must be able to modulate the behavioral, functional, and molecular alterations produced by stress exposure to achieve significant clinical outcomes. This review aims at examining existing clinical and preclinical evidence that supports the ability of atypical antipsychotic drugs (AAPDs) to modulate stress-related alterations. Indeed, while the pharmacodynamic differences between AAPDs have been extensively characterized, less is known on their ability to regulate downstream mechanisms that are critical for functional recovery and patient stabilization. We will discuss stress-related mechanisms, spanning from neuroendocrine function to inflammation and neuronal plasticity, which are relevant for the manifestation of schizophrenic symptomatology, and we will discuss if and how AAPDs may interfere with such mechanisms. Considering the impact of stress in everyday life, we believe that a better understanding of the potential effects of AAPDs on stress-related mechanisms may provide novel and important insights for improving therapeutic strategies aimed at promoting coping mechanisms and enhancing the quality of life of patients affected by psychiatric disorders.

New Tools for Implementing Evidence-Based Care for Serious Mental Illness

More than 11 million adults in the United States have a serious mental illness. Outcomes for these illnesses are good when appropriate treatments are received; however, rates of delivery and utilization of evidence-based care for this population are moderate to low. This article introduces SMI Adviser, a national initiative, supported by the Substance Abuse and Mental Health Services Administration, to advance the use of evidence-based practices and delivery of patient-centered care for the population with serious mental illness. SMI Adviser offers free technical assistance to clinicians caring for this population through accredited educational opportunities, vetted resources, and on-demand consultations.

Efficacy of Intensive Cerebellar Intermittent Theta Burst Stimulation (iCiTBS) in Treatment-Resistant Schizophrenia: a Randomized Placebo-Controlled Study

Trans-cranial magnetic stimulation (TMS) can noninvasively modulate specific brain regions to dissipate symptoms in treatment-resistant schizophrenia (TRS). Citing impaired resting state connectivity between cerebellum and prefrontal cortex in schizophrenia, we aimed to study the effect of intermittent theta burst stimulation (iTBS) targeting midline cerebellum in TRS subjects on a randomized rater blinded placebo control study design. In this study, 36 patients were randomly allocated (using block randomization method) to active and sham iTBS groups. They were scheduled to receive ten iTBS sessions, two per day (total of 1200 pulses) for 5 days in a week. The Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), Schizophrenia Cognition Rating Scale (SCoRS), Simpson-Angus Extrapyramidal Side Effects Scale (SAS), and Clinical Global Impression (CGI) were assessed at baseline, after last session, and at 2 weeks post-rTMS. Thirty patients (16 and 14 in active and sham groups) completed the study. Intention to treat analysis (ITT) using mixed (growth curve) model analysis was conducted. No significant group (active vs sham) × time (pretreatment–end of 10th session–end of 2 weeks post iTBS) interaction was found for any of the variable. No major side effects were reported. Our study fails to show a significant effect of intensive cerebellar iTBS (iCiTBS) on schizophrenia psychopathology, cognitive functions, and global improvement, compared with sham stimulation, in treatment resistant cases. However, we conclude that it is safe and well tolerated. Trials using better localization technique with large sample, longer duration, and better dosing protocols are needed.

Gamma transcranial alternating current stimulation in patients with negative symptoms in schizophrenia: A case series

Non-invasive transcranial brain stimulation therapies, such as transcranial direct current stimulation, have been found to improve negative symptoms in schizophrenia. Another new technique is transcranial alternating current stimulation (tACS). Here we report a series of three patient treated with twice-daily 10min prefrontal 40Hz tACS stimulation over ten days. Patients showed an improvement in the Positive and Negative Syndrome Scale, Scale for the Assessment of Negative Symptoms, and subjective well-being. Furthermore, there was an improvement in the Trail Making Test and word fluency. ytACS merits further investigation in the treatment of schizophrenia symptoms.

A modelling approach to estimate the prevalence of treatment-resistant schizophrenia in the United States

INTRODUCTION

Schizophrenia is a condition that places a significant burden on individuals with the condition, their family, and society. A large proportion of those treated for schizophrenia do not experience treatment response and are referred to as having "treatment-resistant schizophrenia" (TRS). Expert opinion has long held that the prevalence of TRS among individuals with schizophrenia is 30%, but the basis of this estimate is unclear. This article presents a model developed for estimating the prevalence of TRS in the United States 2014.

METHODS

An incidence-prevalence-mortality model was developed to estimate the prevalence of TRS in the United States. The model was populated with data from public health agencies and published literature. Prevalence in 2014 was modelled using a Markov cohort simulation for each birth cohort between 1930 to 2014.

RESULTS

Using different scenarios for baseline incidence, relative risks of mortality, it was estimated that approximately 22% of individuals with schizophrenia would be considered treatment-resistant in 2014.

DISCUSSION

The results suggests that prevalence of TRS may be somewhat lower than the 30% often reported, however this is highly dependent on the definition of treatment resistance. Methods such as this may help answer epidemiological and health policy questions as well as test the influence of key underlying assumptions.

Proniosomes as a Carrier System for Transdermal Delivery of Clozapine

The current study aimed to formulate the clozapine (CLZ) loaded proniosomal gel (PN) and evaluate it's in vitro release, ex vivo permeation and gel properties. CLZ is a BCS class II drug with low bioavailability of 27% and severe adverse drug reactions (ADRs) due to frequent dosing. Proniosomes offer a versatile pro-vesicular approach with potential in transdermal drug delivery. PN-CLZ gel was prepared by the coacervation phase separation method utilizing span-60, cholesterol and lecithin. Optimization of PN gel was done by hit & trial method and the formulations were characterized for particle size, entrapment efficiency (EE), polydispersity index (PDI) and zeta potential (ZP). The optimized formulation had the highest entrapment efficiency of 90% and the average particle size of approx. 325 nm. PDI reflected homogeneity in the formulation. ZP was -59.76 mV, high enough to indicate a stable formulation. The in vitro release studies manifested a sustained release behavior of clozapine from the proniosomal gel. The ex vivo permeation showed noteworthy permeation of the drug through stratum corneum with a steady state flux of 18.26 ug/cm2/hr. The optimized gel was analyzed for pH, spreadability, bioadhesion and rheology. The results suggested that clozapine could be effectively loaded into proniosomal gel for administration through skin.

Indicated association between polygenic risk score and treatment-resistance in a naturalistic sample of patients with schizophrenia spectrum disorders

BACKGROUND

One third of people diagnosed with schizophrenia fail to respond adequately to antipsychotic medication, resulting in persisting disabling symptoms, higher rates of hospitalization and higher costs for society. In an effort to better understand the mechanisms behind resistance to antipsychotic treatment in schizophrenia, we investigated its potential relationship to the genetic architecture of the disorder.

METHODS

Patients diagnosed with a schizophrenia spectrum disorder (N = 321) were classified as either being treatment-resistant (N = 108) or non-treatment-resistant (N = 213) to antipsychotic medication using defined consensus criteria. A schizophrenia polygenic risk score based on genome-wide association studies (GWAS) was calculated for each patient and binary logistic regression was performed to investigate the association between polygenetic risk and treatment resistance. We adjusted for principal components, batch number, age and sex. Additional analyses were performed to investigate associations with demographic and clinical variables.

RESULTS

High levels of polygenic risk score for schizophrenia significantly predicted treatment resistance (p = 0.003). The positive predictive value of the model was 61.5% and the negative predictive value was 71.7%. The association was significant for one (p = 0.01) out of five tested SNP significance thresholds. Season of birth was able to predict treatment-resistance in the regression model (p = 0.05).

CONCLUSIONS

The study indicates that treatment-resistance to antipsychotic medication is associated with higher polygenetic risk of schizophrenia, suggesting a link between antipsychotics mechanism of action and the genetic underpinnings of the disorder.

Clinical and Genetic Factors Associated with Resistance to Treatment in Patients with Schizophrenia: A Case-Control Study

Objectives: To assess clinical and genetic factors affecting response to treatment in a sample of patients with schizophrenia (treatment-resistant patients versus treatment responders). We also aimed at examining if these factors are different when we consider two different resistance classifications (the positive and negative syndrome scale, PANSS and the brief psychiatric rating scale, BPRS). Material and Methods: A case-control study included treatment-resistant patients and good responders. Patients were stratified in two groups based on the established criteria for treatment-resistant schizophrenia using BPRS and PANSS. The study was approved by the ethical committees (references: CEHDF1017; HPC-017-2017) and all patients/legal representatives gave their written consent. Clinical factors were assessed. DNA was obtained using a buccal swab and genotyping for OPRM1, COMT, DRD2 et MTHFR genes using the Lightcycler^® (Roche). Results: Some discrepancies between the BPRS and PANSS definitions were noted in our study when assessing the patients’ psychopathological symptoms and response to treatment. The multivariable analysis, taking the presence versus absence of treatment resistance as the dependent variable, showed that that family history of schizophrenia, university studies, time since the beginning of treatment and chlorpromazine equivalent dose as well as the COMT gene are associated with resistance to treatment. In addition, a gender-related difference was noted for COMT SNP; men with at least one Met allele were more prone to be resistant to treatment than Val/Val patients. Conclusion: Uncovering the clinical and genetic factors associated with resistance to treatment could help us better treat our schizophrenic patients in a concept of personalized medicine.

Remission from antipsychotic treatment in first episode psychosis related to longitudinal changes in brain glutamate

Neuroimaging studies in schizophrenia have linked elevated glutamate metabolite levels to non-remission following antipsychotic treatment, and also indicate that antipsychotics can reduce glutamate metabolite levels. However, the relationship between symptomatic reduction and change in glutamate during initial antipsychotic treatment is unclear. Here we report proton magnetic resonance spectroscopy (1H-MRS) measurements of Glx and glutamate in the anterior cingulate cortex (ACC) and thalamus in patients with first episode psychosis (n = 23) at clinical presentation, and after 6 weeks and 9 months of treatment with antipsychotic medication. At 9 months, patients were classified into Remission (n = 12) and Non-Remission (n = 11) subgroups. Healthy volunteers (n = 15) were scanned at the same three time-points. In the thalamus, Glx varied over time according to remission status (P = 0.020). This reflected an increase in Glx between 6 weeks and 9 months in the Non-Remission subgroup that was not evident in the Remission subgroup (P = 0.031). In addition, the change in Glx in the thalamus over the 9 months of treatment was positively correlated with the change in the severity of Positive and Negative Syndrome Scale (PANSS) positive, total and general symptoms (P<0.05). There were no significant effects of group or time on glutamate metabolites in the ACC, and no differences between either patient subgroup and healthy volunteers. These data suggest that the nature of the response to antipsychotic medication may be related to the pattern of changes in glutamatergic metabolite levels over the course of treatment. Specifically, longitudinal reductions in thalamic Glx levels following antipsychotic treatment are associated with symptomatic improvement.

Engineering brain activity patterns by neuromodulator polytherapy for treatment of disorders

Conventional drug screens and treatments often ignore the underlying complexity of brain network dysfunctions, resulting in suboptimal outcomes. Here we ask whether we can correct abnormal functional connectivity of the entire brain by identifying and combining multiple neuromodulators that perturb connectivity in complementary ways. Our approach avoids the combinatorial complexity of screening all drug combinations. We develop a high-speed platform capable of imaging more than 15000 neurons in 50ms to map the entire brain functional connectivity in large numbers of vertebrates under many conditions. Screening a panel of drugs in a zebrafish model of human Dravet syndrome, we show that even drugs with related mechanisms of action can modulate functional connectivity in significantly different ways. By clustering connectivity fingerprints, we algorithmically select small subsets of complementary drugs and rapidly identify combinations that are significantly more effective at correcting abnormal networks and reducing spontaneous seizures than monotherapies, while minimizing behavioral side effects. Even at low concentrations, our polytherapy performs superior to individual drugs even at highest tolerated concentrations.

Brain disorders are associated with network dysfunctions that are not addressed by conventional drug screens. Here, the authors use high-throughput functional imaging of brain activity in zebrafish larvae to study the effects of individual drugs on network connectivity and demonstrate an algorithm that predicts the most effective drug combinations to normalize both the activity patterns and the animal behavior.

Treatment-Resistant Schizophrenia: Genetic and Neuroimaging Correlates

Schizophrenia is a severe neuropsychiatric disorder that affects approximately 0.5–1% of the population. Response to antipsychotic therapy is highly variable, and it is not currently possible to predict those patients who will or will not respond to antipsychotic medication. Furthermore, a high percentage of patients, approximately 30%, are classified as treatment-resistant (treatment-resistant schizophrenia; TRS). TRS is defined as a non-response to at least two trials of antipsychotic medication of adequate dose and duration. These patients are usually treated with clozapine, the only evidence-based pharmacotherapy for TRS. However, clozapine is associated with severe adverse events. For these reasons, there is an increasing interest to identify better targets for drug development of new compounds and to establish better biomarkers for existing medications. The ability of antipsychotics to improve psychotic symptoms is dependent on their antagonist and reverse agonist activities at different neuroreceptors, and some genetic association studies of TRS have focused on different pharmacodynamic factors. Some genetic studies have shown an association between antipsychotic response or TRS and neurodevelopment candidate genes, antipsychotic mechanisms of action (such as dopaminergic, serotonergic, GABAergic, and glutamatergic) or pharmacokinetic factors (i.e., differences in the cytochrome families). Moreover, there is a growing body of literature on the structural and functional neuroimaging research into TRS. Neuroimaging studies can help to uncover the underlying neurobiological reasons for such resistance and identify resistant patients earlier. Studies examining the neuropharmacological mechanisms of antipsychotics, including clozapine, can help to improve our knowledge of their action on the central nervous system, with further implications for the discovery of biomarkers and the development of new treatments. The identification of the underlying mechanisms of TRS is a major challenge for developing personalized medicine in the psychiatric field for schizophrenia treatment. The main goal of precision medicine is to use genetic and brain-imaging information to improve the safety, effectiveness, and health outcomes of patients via more efficiently targeted risk stratification, prevention, and tailored medication and treatment management approaches. The aim of this review is to summarize the state of art of pharmacogenetic, pharmacogenomic and neuroimaging studies in TRS.

Acute onset clozapine-induced hyperglycaemia: A case report

Clozapine is an atypical antipsychotic which is described to have higher efficacy among all available antipsychotic medications. Clozapine is reserved especially for resistant schizophrenia due to its side effects. Clozapine-induced metabolic syndrome and hyperglycaemia are common long-term side effects and are responsible for increased mortality in patients with schizophrenia. In this case, a patient with resistant schizophrenia was presented with acute-onset hyperglycaemia and delirium with the use of clozapine within a week. Withdrawal of clozapine in the patient led to the improvement in delirium and hyperglycaemia without the use of any hypoglycaemic agent. This case supports the notion that in certain cases clozapine can induce hyperglycemia through possible direct pathophysiological mechanisms within a shorter time frame.

A Pilot Study on Daily Intensive ECT over 8 Days Improved Positive and Negative Symptoms and General Psychopathology of Patients with Treatment-Resistant Schizophrenia up to 4 Weeks after Treatment

OBJECTIVE

For patients with treatment-resistant schizophrenia (TRS) who do not respond to drug therapy, electroconvulsive therapy (ECT) is often employed as an additional treatment. The aims of the present study were to investigate to what extent an 8-day daily ECT treatment might reduce symptoms of schizophrenia among patients with TRS both in the short term (end of the treatment) and medium term, that is 4 and 12 weeks after the treatment.

METHODS

Fourteen patients with TRS based on DSM-5 criteria took part in the present study. ECT consisted of daily sessions for 8 consecutive days. At baseline, at the end of the intervention, and 4 and 12 weeks after study completion, trained psychiatrists assessed the patients' disease severity (positive and negative symptoms; psychopathology) and cognitive functions.

RESULTS

Disease symptoms (positive and negative symptoms; psychopathology) became reduced from baseline to the end of the intervention and to 4 weeks after treatment. Twelve weeks after the intervention symptoms again increased. Cognitive functions decreased from baseline to the end of the study and 4 weeks after treatment. However, by 12 weeks after the intervention, cognitive functions had returned to baseline levels.

CONCLUSION

The pattern of results suggests that an intensive 8-day daily course of ECT reduced psychiatric symptoms (positive and negative symptoms, psychopathology) in both the short and medium term among patients with TRS. The increase in symptoms between 4 and 12 weeks following intervention suggests that booster sessions of ECT could be beneficial.

Comparison of clozapine monitoring and adverse event management in a psychiatrist-only and a clinical pharmacist-psychiatrist collaborative clinic

Introduction

In an effort to establish clinical support for providers prescribing clozapine and to help reverse the national decline in clozapine utilization, a clinical pharmacist began seeing half the clozapine clinic patients, preceding the psychiatrist, at this facility in July 2017. The other half of the clozapine clinic patients continued being seen by the psychiatrist only. The purpose was to determine the impact of the pharmacist on clozapine management and identify barriers to clozapine use to potentially increase its utilization.

Methods

Baseline data (clozapine dose, number of antipsychotics and other psychotropics, A1c, lipids, pulse, body mass index, weight, blood pressure, and number of medications for adverse effects) were collected via chart review from the first clinic visit and each follow-up visit. A provider survey was used to identify barriers and solutions to prescribing clozapine.

Results

There were no statistically significant differences from baseline in patient outcomes between the collaborative and psychiatrist-only group. In the prepharmacist to postpharmacist analysis, there was a decrease in number of antipsychotics (−0.27 ± 0.65), number of other psychotropics (−0.18 ± 0.41), A1c (−0.04% ± 0.25%), clozapine dose (−7.96 mg ± 19.58 mg), and total cholesterol (−15.73 mg/dL ± 42.31 mg/dL). There were more pharmacologic (71 vs 19) and nonpharmacologic (154 vs 3) interventions documented in the collaborative group compared to the psychiatrist-only group. Eleven providers (69%) completed the survey. Providers' perception of patient refusal of monitoring was the barrier that received the most responses (54%). A pharmacist seeing every clozapine clinic patient was the solution that received the most responses (90%).

Discussion

Trends were seen for decreasing the number of antipsychotics, other psychotropics, A1c, and total cholesterol as well as an increased number of nonpharmacologic and pharmacologic interventions documented in the collaborative group. Providers identified that pharmacists seeing every clozapine clinic patient would be a solution to clozapine underutilization, which demonstrates the perceived value of pharmacist involvement.

The role of the gut microbiota in schizophrenia: Current and future perspectives

OBJECTIVES

Schizophrenia is a poorly understood chronic disease. Its pathophysiology is complex, dynamic, and linked to epigenetic mechanisms and microbiota involvement. Nowadays, correlating schizophrenia with the environment makes sense owing to its multidimensional implications: temporal and spatial variability. Microbiota involvement and epigenetic mechanisms are factors that are currently being considered to better understand another dimension of schizophrenia.

METHODS

This review summarises and discusses currently available information, focussing on the microbiota, epigenetic mechanisms, technological approaches aimed at performing exhaustive analyses of the microbiota, and psychotherapies, to establish future perspectives.

RESULTS

The connection between the microbiota, epigenetic mechanisms and technological developments allows for formulating new approaches objectively oriented towards the development of alternative psychotherapies that may help treat schizophrenia.

CONCLUSIONS

In this review, the gut microbiota and epigenetic mechanisms were considered as key regulators, revealing a potential new aetiology of schizophrenia. Likewise, continuous technological advances (e.g. culturomics), aimed at the microbiota-gut-brain axis generate new evidence on this concept.

Treatment resistant schizophrenia - review and a call to action

Recovery rates in schizophrenia remain suboptimal with up to one-third resistant to standard treatments, a population prevalence of 0.2%. Clozapine is the only evidenced-based treatment for treatment resistant schizophrenia (TRS), yet there are significant delays in its use or it may not be trialled, potentially impacting the chance of recovery. Better outcomes with earlier use of clozapine may be possible. There is emerging evidence that early treatment resistance is not uncommon from the earliest stages of psychosis. In this review, we provide an update on TRS, its epidemiology and its management, with a specific focus on the optimal use and timing of clozapine and augmentation strategies for the one-third of patients who do not respond to clozapine.