An international research agenda for clozapine-resistant schizophrenia

Sex differences in clozapine prescription: Results from an Italian 30-year health records registry

BACKGROUND

Clozapine is the only approved medication for treatment-resistant schizophrenia which is equally prevalent on male and female patients. However, studies showed that clozapine is less frequently prescribed to women compared to men.

AIMS

This study aims to investigate the role of sex in clozapine prescription, taking into account potential sociodemographic and clinical confounding factors.

METHODS

Patients aged 18-65, with a diagnosis of schizophrenia spectrum disorders were selected from the 46,222 individuals who had access to outpatient psychiatric services of Ferrara, Italy, from 1991 to 2021. Sociodemographic and clinical information including clozapine prescription timing and dosage were analyzed.

RESULTS

Among 3901 patients with a schizophrenia spectrum disorders, those who had been prescribed clozapine (189, 4.8%) were significantly more likely to be male (57%), younger at admission to care (30 vs 39.7 years old) and with a schizophrenia diagnosis (77% vs. 49%) compared to those without clozapine prescription. Within patients with a diagnosis of schizophrenia (n = 145), women (n = 60, 41%), compared to men, experienced twice the delay to be prescribed clozapine, both from the prescription of the first antipsychotic to clozapine (mean 1265.7 vs 746.6 days in men, p = 0.03) and from the prescription of the third antipsychotic to clozapine (mean 1214.5 vs 725.8 days in men, p = 0.03). Also, within those diagnosed with schizophrenia, women with a diagnosis of schizophrenia were less likely than men to be prescribed clozapine after the first and third antipsychotic considering both crude (HR = 0.66, p = 0.07; HR = 0.53, p = 0.025) and adjusted hazard ratios (HR = 0.65, p = 0.07; HR = 0.51, p = 0.021).

CONCLUSIONS

This study showed disparities based on sex in both the use and timing of clozapine, which disadvantages women diagnosed with schizophrenia. Further interventions are needed to increase awareness of possible sex-based barriers to clozapine use in clinical practice, measurement of sources of gender specific bias, and quality improvement initiatives to continuously address challenges in providing adequate treatment to this vulnerable population.

Frequency, correlates and outcomes of Benzodiazepine use during Cariprazine treatment: A pooled post-hoc analysis from four 6-week, placebo-controlled trials in patients with an acute exacerbation of schizophrenia

Given the frequent prescription of benzodiazepines (BZDs) as adjunctive treatment to antipsychotics, this study aimed to uncover how BZD use affects treatment outcomes with cariprazine (CAR). This post-hoc analysis used pooled data from four placebo-controlled trials in patients with acute schizophrenia. Efficacy evaluations involved changes from baseline to Week 6 on PANSS Total Score, Marder Positive Factor Score, Excitement Component Subscale Score, and Marder Anxiety Single Item Score. Safety evaluations focused on extrapyramidal symptoms and akathisia. Comparisons were made between CAR alone vs. placebo (PLB) alone; CAR+BZD vs. PLB+BZD; CAR alone vs. CAR+BZD; and PLB alone vs. PLB+BZD. Data from 1643 patients were analysed (CAR only=943; CAR+BZD=132; PLB only=475; PLB+BZD=93). CAR alone yielded significantly greater improvement on all measures than PLB alone. CAR+BZD yielded significantly greater improvements in overall schizophrenia symptoms than PLB+BZD. CAR alone showed greater improvements in overall, positive, and anxiety symptoms compared to CAR+BZD. PLB alone yielded significantly greater improvements in positive and anxiety symptoms than PLB+BZD. Anxiety and agitation were the leading reasons for BZD administration. CAR was associated with more akathisia and EPS in both the non-BZD and BZD-user groups than PLB. The results support the superior efficacy of CAR with or without BZD co-treatment for total and positive symptoms of schizophrenia compared to PLB with or without BZD use. These findings suggest BZDs should be used for emergent symptoms like anxiety or agitation, rather than core schizophrenia symptoms.

Clozapine Induces Agranulocytosis via Inflammatory and Hematopoietic Cytokine Induction of the JAK-STAT Signaling Pathway: Evidence From Network Pharmacology and Molecular Docking

BACKGROUND

Clozapine exhibits significant therapeutic efficacy in schizophrenia, especially treatment-resistant schizophrenia. However, clozapine can cause agranulocytosis, a fatal adverse effect, and the aim of this study is to explore this mechanism based on network pharmacology and molecular docking.

METHOD

Six and two databases were used to identify targets associated with clozapine and agranulocytosis, respectively. The bioinformatics online platform was used to identify overlaps between the drug and disease targets. The protein-protein interaction (PPI) network was characterized using Cystoscope 3.10.1 and STRING. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) were analyzed using the DAVID online platform. A drug-target-pathway-disease network was constructed utilizing Cystoscope 3.10.1. The Auto Dock Vina and PyMOL software were used to verify the molecular docking of clozapine and core targets.

RESULTS

The analysis revealed 188 overlapping targets. The PPI and KEGG enrichment pathway analyses demonstrated that clozapine induces agranulocytosis by modulating the hematopoietic cell lineage and JAK-STAT signaling pathways via interleukin-3 (IL3), IL6, IL2 receptor subunit alpha (IL2RA), and granulocyte colony-stimulating factor. Binding energies between clozapine and core targets were favorable (< -7.0 kcal/mol).

CONCLUSION

Clozapine-induced agranulocytosis may be linked to the JAK-STAT inflammatory signaling pathway through inflammatory and hematopoietic-related cytokines. Our findings enhance our comprehension of the potential mechanisms underlying clozapine-induced agranulocytosis.

Generation of patient-derived induced pluripotent stem cell line UJSi004-A from ultra-treatment-resistant schizophrenia

Schizophrenia is a severe mental illness with disabling effects. Induced pluripotent stem cells (iPSCs) are generated by reprogramming peripheral blood mononuclear cells (PBMCs) from patients with ultra-treatment-resistant schizophrenia (UTRS). iPSCs have normal karyotype, express pluripotency markers and differentiate into three germ layers in vivo. This iPSC cell line carries the genetic information of the patient and is a good model for studying disease mechanisms and developing new therapies.

Multidimensional Epigenetic Clocks Demonstrate Accelerated Aging Across Physiological Systems in Schizophrenia: A Meta-Analysis

IMPORTANCE

Schizophrenia is associated with increased age-related morbidity, mortality, and frailty, which are not entirely explained by behavioral factors. Prior studies using epigenetic clocks have suggested that schizophrenia is associated with accelerated aging, however these studies have primarily used unidimensional clocks that summarize aging as a single "biological age" score.

OBJECTIVE

This meta-analysis uses multidimensional epigenetic clocks that split aging into multiple scores to analyze biological aging in schizophrenia. These novel clocks may provide more granular insights into the mechanistic relationships between schizophrenia, epigenetic aging, and premature morbidity and mortality.

STUDY SELECTION

Selected studies included patients with schizophrenia-spectrum disorders and non- psychiatric controls with available DNA methylation data. Seven cross-sectional datasets were available for this study, with a total sample size of 1,891 patients with schizophrenia and 1,881 controls.

DATA EXTRACTION AND SYNTHESIS

Studies were selected by consensus Meta-analyses were performed using fixed-effect models.

MAIN OUTCOMES AND MEASURES

We analyzed multidimensional epigenetic clocks, including causality- enriched CausAge clocks, physiological system-specific SystemsAge clocks, RetroelementAge, DNAmEMRAge, and multi omics-informed OMICmAge. Meta-analyses examined clock associations with schizophrenia disease status and clozapine use, after accounting for age and sex.

RESULTS

Overall SystemsAge, CausAge, DNAmEMRAge, and OMICmAge scores demonstrated increased epigenetic aging in patients with schizophrenia after strict multiple-comparison testing. Ten of the eleven SystemsAge sub-clocks corresponding to different physiological systems demonstrated increased aging, with strongest effects for Heart and Lung followed by Metabolic and Brain systems. The causality- enriched clocks indicated increases in both damaging and adaptive aging, though these effects were weaker compared to SystemsAge scores. OMICmAge indicated changes in multiple clinical biomarkers, including hematologic and hepatic markers that support system-specific aging, as well as novel proteins and metabolites not previously linked to schizophrenia. Most clocks demonstrated age acceleration at the first psychotic episode. Notably, clozapine use was associated with increased Heart and Inflammation aging, which may partially be driven by smoking. Most results survived strict Bonferroni multiple testing correction.

CONCLUSIONS AND RELEVANCE

These are the first analyses of novel multidimensional clocks in patients with schizophrenia and provide a nuanced view of aging that identifies multiple organ systems at high risk for disease in schizophrenia-related disorders.

The relational institution: an ethnographic study of recovery orientation and relational engagement on a psychiatric rehabilitation ward in London

BACKGROUND

In the UK, inpatient psychiatric rehabilitation services for complex psychosis aim to provide recovery-orientated treatment to patients, with the goal of supporting sustained stepdown into community living. The extent to which rehabilitation services uphold this recovery orientation is associated with better outcomes. However, few studies have been able to ascertain what promotes or prevents recovery orientation in inpatient settings.

METHODS

We conducted an ethnographic study of treatment on a National Health Service (NHS) psychiatric rehabilitation ward in London over six months during August 2022-February 2023. Data were collected through participant observation and semi-structured interviews with 9 patients and 14 staff members. Fieldnotes and interview transcripts were analysed using situational analysis.

RESULTS

Our analysis highlights the importance of what we term 'relational engagement' between staff and patients to nurture and sustain recovery-orientated treatment. This relational engagement was embodied through small acts of genuine human connection grounded in mutual acceptance and affective bonding; close attention to detail that communicated curiosity and respect; and recognition, appreciation, and encouragement of the slow and gradual progress that characterises recovery in complex psychosis. Yet, this relational engagement was often limited or foreclosed by the social environment of the ward and the wider institutional context. Limiting elements included the dominance of hospital logics geared towards high-throughput acute treatment and risk management; the presence of audit culture that led to a level of standardisation curtailing more genuine human connection; and staff demoralisation driven by events on and off the ward, including system-wide crises and more localised conflicts and disturbances. Some of these conflicts involved discrimination, most prominently anti-Black racism and homophobia, reflecting wider structural inequalities that characterise inpatient psychiatric populations and the healthcare workforce.

CONCLUSION

Relationships, often under-prioritised in mental health services, were a key cornerstone of recovery-orientated treatment on a psychiatric rehabilitation ward. The shaping of therapeutic relationships amounted to an active process of relational engagement, which may be afforded or constrained by complex social elements requiring careful consideration in inpatient psychiatry. These social elements go beyond more surface-level factors such as staff training, knowledge, or attitudes and may require structural and system-level interventions.

Longitudinal changes in DNA methylation associated with clozapine use in treatment-resistant schizophrenia from two international cohorts

The second-generation antipsychotic clozapine is used as a medication for treatment-resistant schizophrenia. It has previously been associated with epigenetic changes in pre-clinical rodent models and cross-sectional studies of treatment-resistant schizophrenia. Cross-sectional studies are susceptible to confounding, however, and cannot disentangle the effects of diagnosis and medication. We therefore profiled DNA methylation in sequential blood samples (n = 126) from two independent cohorts of patients (n = 38) with treatment-resistant schizophrenia spectrum disorders who commenced clozapine after study enrolment and were followed up for up to six months. We identified significant non-linear changes in cell-type proportion estimates derived from DNA methylation data - specifically B-cells - associated with time on clozapine. Mixed effects regression models were used to identify changes in DNA methylation at specific sites associated with time on clozapine, identifying 37 differentially methylated positions (DMPs) (p < 5 × 10-5) in a linear model and 90 DMPs in a non-linear quadratic model. We compared these results to data from our previous epigenome-wide association study (EWAS) meta-analysis of psychosis, finding evidence that many previously identified DMPs associated with schizophrenia and treatment-resistant schizophrenia might reflect exposure to clozapine. In conclusion, our results indicate that clozapine exposure is associated with changes in DNA methylation and cellular composition. Our study shows that medication effects might confound many case-control studies of neuropsychiatric disorders performed in blood.

Dysfunction of the NMDA Receptor in the Pathophysiology of Schizophrenia and/or the Pathomechanisms of Treatment-Resistant Schizophrenia

For several decades, the dopamine hypothesis contributed to the discovery of numerous typical and atypical antipsychotics and was the sole hypothesis for the pathophysiology of schizophrenia. However, neither typical nor atypical antipsychotics, other than clozapine, have been effective in addressing negative symptoms and cognitive impairments, which are indices for the prognostic and disability outcomes of schizophrenia. Following the development of atypical antipsychotics, the therapeutic targets for antipsychotics expanded beyond the blockade of dopamine D2 and serotonin 5-HT2A receptors to explore the partial agonism of the D2 receptor and the modulation of new targets, such as D3, 5-HT1A, 5-HT7, and metabotropic glutamate receptors. Despite these efforts, to date, psychiatry has not successfully developed antipsychotics with antipsychotic properties proven to be superior to those of clozapine. The glutamate hypothesis, another hypothesis regarding the pathophysiology/pathomechanism of schizophrenia, was proposed based on clinical findings that N-methyl-D-aspartate glutamate receptor (NMDAR) antagonists, such as phencyclidine and ketamine, induce schizophrenia-like psychotic episodes. Large-scale genome-wide association studies (GWASs) revealed that approximately 30% of the risk genes for schizophrenia (the total number was over one hundred) encode proteins associated with glutamatergic transmission. These findings supported the validation of the glutamate hypothesis, which was inspired by the clinical findings regarding NMDAR antagonists. Additionally, these clinical and genetic findings suggest that schizophrenia is possibly a syndrome with complicated pathomechanisms that are affected by multiple biological and genetic vulnerabilities. The glutamate hypothesis has been the most extensively investigated pathophysiology/pathomechanism hypothesis, other than the dopamine hypothesis. Studies have revealed the possibility that functional abnormalities of the NMDAR play important roles in the pathophysiology/pathomechanism of schizophrenia. However, no antipsychotics derived from the glutamatergic hypothesis have yet been approved for the treatment of schizophrenia or treatment-resistant schizophrenia. Considering the increasing evidence supporting the potential pro-cognitive effects of glutamatergic agents and the lack of sufficient medications to treat the cognitive impairments associated with schizophrenia, these previous setbacks cannot preclude research into potential novel glutamate modulators. Given this background, to emphasize the importance of the dysfunction of the NMDAR in the pathomechanism and/or pathophysiology of schizophrenia, this review introduces the increasing findings on the functional abnormalities in glutamatergic transmission associated with the NMDAR.

Efficacy and acceptability of interventions to reduce antipsychotic polypharmacy: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Antipsychotic polypharmacy (APP) is frequent but evidence-based guidelines on reducing APP to antipsychotic monotherapy (APM) are sparse. We aimed to systematically review clinical interventions randomizing patients to reducing APP to APM versus continuing APP.

METHODS

Systematic literature review searching Medline and Embase (latest search January 10, 2024) for randomized clinical trials (RCTs) studying interventions comparing individuals randomized to reduction of APP to APM with individuals continuing on APP. Two independent reviewers performed the literature screening, data extraction, and risk of bias assessment (RoB2). We performed random effects meta-analyses on the main outcome all-cause discontinuation/"acceptability" of the treatment strategy and secondary outcomes change in psychopathology, functional level, and side effects.

RESULTS

The search identified 4672 hits, whereof 8 trials (N = 1204, 6 patient-level RCTs and 2 cluster-RCTs) were included, primarily in patients with schizophrenia. All trials were associated with high risk of bias. Compared to APP continuation, reduction to APM was associated with no significant change in all-cause discontinuation (studies = 6, n = 455, RR = 1.48, 95%CI = 0.74-2.95, I2 = 78 %) or inefficacy-related discontinuation (studies = 5, n = 351, RR = 1.60, 95%CI = 0.46-5.55, I2 = 70 %). Patients randomized to APM showed a trend towards greater reduction in psychopathology (studies = 5, n = 244, SMD = -0.24, 95%CI = -0.49, 0.02, I2 = 0 %) but no difference in functional level nor side effects. The cluster-RCTs found that interventions at the departmental level can result in lower rates of APP.

CONCLUSION

Although switching patients from APP to APM can be a viable approach, too few RCTs exist on this important topic. Clinicians need to evaluate potential benefits and risks of APP and APM on an individual basis.

PROSPERO REGISTRATION

CRD42022329955.

Challenges, unmet needs and future directions - a critical evaluation of the clinical trial landscape in schizophrenia research

INTRODUCTION

Developing novel antipsychotic mechanisms of action and repurposing established compounds for the treatment of schizophrenia is of utmost importance to improve relevant symptom domains and to improve the risk/benefit ratio of antipsychotic compounds. Novel trial design concepts, pathophysiology-based targeted treatment approaches, or even the return to old values may improve schizophrenia outcomes in the future.

AREAS COVERED

In this review of the clinical trial landscape in schizophrenia, we present an overview of the challenges and gaps in current clinical trials and elaborate on potential solutions to improve the outcomes of people with schizophrenia.

EXPERT OPINION

The classic parallel group design may limit substantial advantages in drug approval or repurposing. Collaborative approaches between regulatory authorities, industry, academia, and funding agencies are needed to overcome barriers in clinical schizophrenia research to allow for meaningful outcome improvements for the patients.

Monitoring the Effectiveness of Treatment in Women with Schizophrenia: New Specialized Cooperative Approaches

Women with schizophrenia have specific health needs that differ from those of men and that change through successive life stages. We aimed to review the biopsychosocial literature on schizophrenia that addresses clinically important questions related to the treatment of women, including somatic morbi-mortality, hyperprolactinemia, comorbid substance use disorders, social risk factors, and medication effectiveness/safety. Data search terms were as follows: (Morbidity AND mortality) OR hyperprolactinemia OR ("substance use disorders" OR addictions) OR ("social risk factors") OR ("drug safety" OR prescription) AND women AND schizophrenia. A secondary aim was to describe a method of monitoring and interdisciplinary staff strategies. Schizophrenia patients show an increased risk of premature death from cardiovascular/respiratory disease and cancer compared to the general population. The literature suggests that close liaisons with primary care and the introduction of physical exercise groups reduce comorbidity. Various strategies for lowering prolactin levels diminish the negative long-term effects of hyperprolactinemia. Abstinence programs reduce the risk of victimization and trauma in women. Stigma associated with women who have serious psychiatric illness is often linked to reproductive functions. The safety and effectiveness of antipsychotic drug choice and dose differ between men and women and change over a woman's life cycle. Monitoring needs to be multidisciplinary, knowledgeable, and regular.