Long-Term Outcome of Clozapine in Treatment-Resistant Schizophrenia

Prevalence, demographics, and clinical characteristics of suicide attempts in first episode drug-naïve schizophrenia patients with comorbid severe depression

BACKGROUND

Suicide attempts have been intensively examined in chronic schizophrenia (SCZ) patients with comorbid depression. This study aimed to investigate the prevalence and clinical correlates of suicide attempts in Chinese first episode drug-naïve (FEDN) SCZ patients with comorbid severe depression.

METHODS

Totally 317 FEDN SCZ patients were recruited into the study. Patients were assessed for symptoms using the 24-item Hamilton Depression Scale (HAMD24), the Hamilton Anxiety Scale (HAMA), and the Positive and Negative Syndrome Scale (PANSS). Plasma glucose and lipids were measured. A score of more than 35 on the HAMD24 was defined as severe depression.

RESULTS

Suicide attempts occurred at a higher rate in patients with severe depression than in those without (33.4% vs 16.7%). Among patients with severe depression, HAMD and PANSS total score were higher in suicide attempters compared to non-attempters (all p < 0.05). PANSS total score was independently related to suicide attempts in FEDN SCZ patients who had severe depression (OR = 1.02, p < 0.05).

CONCLUSION

Suicide attempts are more prevalent in FEDN SCZ patients with comorbid severe depression than in those without. Psychotic symptoms might be involved in suicide attempts in FEDN SCZ patients with severe depression, while depressive symptoms might not.

Association of new-onset diabetes mellitus in adults with schizophrenia treated with clozapine versus patients treated with olanzapine, risperidone, or quetiapine: A systematic review and meta-analysis

INTRODUCTION

Many articles suggest that clozapine was strongly associated with a higher incidence of new-onset diabetes mellitus, and the issue has remained unsettled. Many articles have compared clozapine with FGAs, but few have compared clozapine with SGAs. We aimed to compare the risk of new-onset diabetes mellitus in adults with schizophrenia treated with clozapine and other SGAs.

METHODS

We conducted a comprehensive search of databases from their inception up until August 26, 2023. The specific databases include PubMed, Embase and others. We included non-randomized controlled trials involving the use of SGAs such as clozapine, olanzapine, risperidone, quetiapine, amisulpride, and zotepine, with a focus on new-onset diabetes mellitus as an outcome. We utilized odds ratio with 95 % credible intervals (95 % CI) as our effect size measures. The study protocol is registered with PROSPERO, number CRD42024511280.

RESULTS

We included 7 studies with sufficient data to include in the meta-analysis. A total of eight studies with 641,48 participants met the eligibility criteria. The OR of the incidence rates of new-onset diabetes between clozapine and olanzapine was 0.95 (95 % CI:[0.82-1.09]), between clozapine and risperidone was 1.25 (95 % CI: [1.09-1.44]), between clozapine and quetiapine was 1.44 (95 % CI: [0.92-2.25]).

CONCLUSION

In patients with schizophrenia, clozapine has been found to have a higher rate of new-onset diabetes mellitus compared to risperidone. However, there was no significant difference in incidence rate between clozapine versus olanzapine and quetiapine. These findings can assist clinicians in balancing the risks and benefits of those drugs.

Real-World Evidence of Antipsychotic Monotherapy Versus Polypharmacy in the Treatment of Schizophrenia Spectrum Disorders

PURPOSE/BACKGROUND

It is still not well known whether antipsychotic monotherapy versus polypharmacy differs in terms of efficacy in the emergency department (ED) utilization, presentation with agitation/aggression, and rehospitalization in schizophrenia spectrum disorders (SSD) patients. This study aimed to determine the effectiveness of antipsychotic monotherapy and polypharmacy for these outcomes in the real world.

METHODS/PROCEDURES

The study was conducted with electronic health records of 669 SSD patients admitted to the ED. Patients were evaluated in 4 groups according to antipsychotic use at the first admission to ED: antipsychotic noncompliance for more than 90 days, antipsychotic noncompliance for 15 to 90 days, antipsychotic monotherapy, and polypharmacy. All patients followed up for at least 1 year after index admission. The primary outcomes determined an association between antipsychotic monotherapy versus polypharmacy and all-cause psychiatric hospitalization between the groups after index admission in the SSD.

FINDINGS/RESULTS

The groups, including patients with antipsychotic noncompliance, had higher ED visits, more hospitalizations, and more admissions with agitation/aggression compared with antipsychotic monotherapy or polypharmacy. However, no differences were found between monotherapy and polypharmacy groups regarding these outcomes. In addition, there was no difference in the risk of hospitalization in monotherapy antipsychotic users compared with polypharmacy users. Patients discharged with monotherapy or polypharmacy also had similar rehospitalization rates at follow-up.

IMPLICATIONS/CONCLUSIONS

There is no positive evidence that recommending polypharmacy over antipsychotic monotherapy is superior with regard to the resulting frequency of ED visits, ED admissions with agitation/aggression, hospitalization, and rehospitalization. In this context, antipsychotic monotherapy may be preferred over polypharmacy in patients who are not resistant to treatment.

Evaluating Monitoring Guidelines of Clozapine-Induced Adverse Effects: a Systematic Review

BACKGROUND AND OBJECTIVES

Despite the evidence that no other antipsychotic is effective as clozapine for the treatment of resistant schizophrenia, it is associated with various metabolic, neuroendocrine, cardiovascular, and gastrointestinal adverse effects. Guidelines aiming to address the monitoring of clozapine's (serious) adverse effects can be helpful to prevent and treat these effects. However, many of these guidelines seem to lack one or more important monitoring recommendations. We aimed to systematically review the content and quality of existing monitoring guidelines/recommendations for clozapine-induced adverse effects.

METHODS

A comprehensive and systematic literature search, using the MEDLINE, Embase, Web of Science, and Cochrane databases, was conducted for guidelines/recommendations on the monitoring of clozapine-induced adverse events, published between January 2004 and April 2023 (last search 16 April 2023). Only peer-reviewed published guidelines reporting on the comprehensive monitoring of all major clozapine-induced adverse effects and including evidence-based recommendations, developed after the year 2004, were included. Studies reporting on the monitoring of adverse effects of clozapine without being a formal guideline, guidelines reporting on the monitoring of one or a limited number of adverse effects of clozapine, guidelines that were not peer reviewed or published, expert opinion papers without formal consensus guideline development, or guidelines developed before the year 2004, were excluded. The Appraisal of Guidelines for Research and Evaluation II (AGREE-II) tool was used to evaluate the guidelines/recommendations' quality.

RESULTS

Only one guideline met the inclusion criteria. This consensus statement made recommendations for hematological monitoring, and the monitoring of metabolic, cardiac, and three other adverse effects. Highest scores for the qualitative assessment were found for the domains "scope and purpose" (66.7%), "clarity of presentation" (44.4%), and "editorial independence" (66.7%). Lowest scores were found for "rigor of development" (14.6%) and "applicability" (0%).

CONCLUSIONS

Future guidelines should develop more comprehensive recommendations about specific clozapine-induced adverse effects, including constipation, myocarditis, tachycardia, and seizures, as well as include a rechallenge policy. There is an urgent need for well-developed, methodologically stringent, guidelines.

REGISTRATION

PROSPERO registration number, CRD42023402480.

Rho kinase inhibitors ameliorate cognitive impairment in a male mouse model of methamphetamine-induced schizophrenia

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