Treatment-resistant schizophrenia--the role of clozapine

Association between treatment resistance and cognitive function in schizophrenia

INTRODUCTION

Treatment-resistant schizophrenia (TRS) affects around 30% of individuals with schizophrenia. About half of the patients with TRS who are treated with clozapine do not show a meaningful clinical response, that is, clozapine resistance. To date, the relationship between cognitive function and treatment response categories is not entirely clear. This study evaluated the cognitive performance across subgroups stratified by treatment response, and we hypothesised that cognitive impairment increases with increased treatment resistance.

METHODS

This study was conducted at the Institute of Mental Health, Singapore, and included healthy controls and people with schizophrenia categorised into these groups: antipsychotic-responsive schizophrenia (ARS), clozapine-responsive TRS (TRS-CR) and clozapine-resistant TRS (ultra-treatment-resistant schizophrenia [UTRS]). Cognitive function was assessed using the Brief Assessment of Cognition-Short Form. Symptoms were measured with the Positive and Negative Syndrome Scale (PANSS). The planned statistical analyses included adjustments for covariates such as age, sex, PANSS scores and antipsychotic dose, which might affect cognitive function.

RESULTS

There were significant differences in overall cognitive performance between the groups: ARS had the least impairment, followed by TRS-CR and UTRS. Antipsychotic dose, and PANSS negative and disorganisation/cognitive factors were significant predictors of overall cognitive function in all patient groups.

CONCLUSIONS

Our study found differences in cognitive function that aligned with levels of treatment resistance: the greater the degree of treatment resistance, the poorer the cognitive function. Interventions to improve negative and disorganisation symptoms might be effective to enhance the cognitive function and treatment outcomes in schizophrenia.

Investigating Cannabidiol's potential as a supplementary treatment for schizophrenia: A narrative review

Schizophrenia presents a complex mental health challenge, often inadequately addressed by existing antipsychotic treatments, leading to persistent symptoms and adverse effects. Hence, developing alternative therapeutic approaches is crucial. Cannabidiol (CBD), a nonpsychoactive compound in Cannabis sativa, has been extensively explored for its therapeutic potential in treating psychiatric disorders, including schizophrenia. CBD exhibits antipsychotic, anxiolytic, and neuroprotective effects. However, distinguishing the individual effects of CBD and THC remains challenging. Therefore, this review aims to critically analyze the potential role of CBD as an adjunctive therapy in schizophrenia treatment. The therapeutic action of CBD may involve activating the 5-hydroxytryptamine 1A receptors and suppressing the G-protein-coupled receptor 55, thereby affecting various neurotransmitter systems. Additionally, the anti-inflammatory and antioxidative effects of CBD may contribute to alleviating neuroinflammation linked to schizophrenia. Compared to typical antipsychotics, CBD demonstrates a lower incidence of side effects and it exhibited favorable tolerability in clinical trials. A 2012 clinical trial demonstrated the efficacy of CBD in reducing both positive and negative symptoms of schizophrenia, presenting a safer profile than that of traditional antipsychotics. However, further research is needed to fully establish the safety and efficacy of CBD as an adjunctive treatment. Future research directions encompass exploring detailed antipsychotic mechanisms, long-term safety profiles, interactions with current antipsychotics, optimal dosing, and patient-specific factors such as genetic predispositions. Despite these research needs, the potential of CBD to enhance the quality of life and symptom management positions it as a promising candidate for innovative schizophrenia treatment approaches.

The role of control groups in non-pharmacological randomised controlled trials of treatment-resistant schizophrenia: A systematic review and meta-analysis

Control groups used in randomised controlled trials investigating psychological interventions for depression and anxiety disorders have effects of their own. This has never been investigated for schizophrenia, in particular treatment-resistant schizophrenia. This systematic review and meta-analysis aimed to examine how control groups in randomised controlled trials on psychological interventions for treatment-resistant schizophrenia behave in their effects on general symptomatology. In a search of various databases until July 2023, 31 eligible studies with 3125 participants were found whose control groups were assigned to four categories: active, inactive, treatment as usual and waitlist. The analyses showed that psychological interventions had a greater effect on symptom reduction to all control groups combined. When separating the control groups, only compared to TAU and waitlist controls the psychological interventions were superior. The difference was larger when less active control groups (e.g. waitlist - or treatment as usual control groups) were used. All control groups were associated with an improvement in symptoms from pre- to post-measurement point, with the greatest improvement observed in the inactive control group. The results are preliminary, but they suggest that the choice of the control group has a considerable impact on study effects as it has been shown in other psychiatric diagnoses.

Effective and safe use of intramuscular clozapine in a patient presenting with catatonia and thrombocytopenia

Clozapine is the most effective medication for the management of treatment-resistant schizophrenia and schizoaffective disorder, and its discontinuation can pose significant challenges in treatment. We present a patient with a diagnosis of schizoaffective disorder who was stable on clozapine for a decade until discontinuation due to thrombocytopenia. She experienced a relapse of her illness, presenting with psychotic and catatonic features with poor oral intake and physical health complications requiring a lengthy admission to the hospital. There was a poor response to alternative antipsychotics and a full course of electroconvulsive therapy. Intramuscular (IM) clozapine was initiated due to catatonia and refusal to accept oral medications. After receiving 10 doses of IM clozapine, she started accepting oral clozapine and made a full recovery within a few weeks. The low platelet count was persistent, and a bone marrow biopsy showed results consistent with immune thrombocytopenia being the cause of that low platelet count.

Evaluation of the pharmacodynamic interaction effect of augmentation agents with clozapine in patients with treatment-resistant schizophrenia: A simulation study of clinical data

INTRODUCTION

The aim of the study was to evaluate interaction effect of various augmentation strategies with clozapine in patients with Treatment-resistant schizophrenia.

METHODS

Data was extracted for change in positive and negative syndrome scale (PANSS) or brief psychiatric rating scale (BPRS) scores for monotherapy with various antipsychotic agents alone and their combination with clozapine. Individual patient data was generated using simulation of data (factorial trial framework) from published clinical trials for sample sizes from eight to 400 to evaluate interaction effect through linear modeling. Dose equivalents were calculated, and best fit models were determined for simulated data.

RESULTS

The polynomial model was found to be the best fit for the simulated data to determine interaction effect of combination. The clozapine augmentation with risperidone and ziprasidone was found to be antagonistic, whereas it was additive for haloperidol, aripiprazole, and quetiapine. A synergistic effect was observed for ECT combined with clozapine (Interaction effect: -7.62; p <0.001). A sample size of 250-300 may be sufficient to demonstrate a clinically significant interaction in future trials.

CONCLUSION

Clozapine may be augmented with electroconvulsive therapy, leading to the enhancement of antipsychotic effect. Though some antipsychotics like aripiprazole demonstrate additive effects, they may also add to the adverse effects.

Transformative Outcomes With Paliperidone Long-Acting Injection in Severe Treatment-Resistant Schizophrenia: A Case Report and Literature Review

Treatment-resistant schizophrenia (TRS) presents considerable challenges in contemporary psychiatric practice due to inadequate response to conventional antipsychotic treatments. Paliperidone, the primary active metabolite of risperidone, particularly in its long-acting injectable (LAI) form, has emerged as a promising option for TRS due to its consistent medication delivery, reducing symptom exacerbation and relapse associated with oral dosing fluctuations. This case report presents the clinical journey of a 42-year-old female diagnosed with schizophrenia at age 15. Despite numerous hospital admissions and trials of various oral and injectable antipsychotics, including clozapine and electroconvulsive therapy (ECT), her symptoms persisted. During her last admission, her condition showed minimal improvement despite extensive pharmacological interventions. Introducing paliperidone LAI while tapering off other antipsychotics led to significant improvements within four weeks. The patient exhibited reduced hallucinatory behaviour, delusions, and disorganized behaviour. Follow-up assessments confirmed sustained progress, with the patient showing increased engagement in daily activities and reduced irritability and suspiciousness. This case underscores the potential efficacy of paliperidone LAI in managing TRS. The patient's notable improvement highlights the importance of personalized treatment plans and continuous monitoring in complex psychiatric conditions. Its favourable safety and tolerability profile further supports its use as a long-term treatment option for TRS, potentially leading to enhanced patient compliance and overall quality of life. The significant symptomatic relief and functional improvement observed advocate for the consideration of paliperidone LAI as a promising therapeutic option for TRS, with the potential to be considered in the future among the first-line treatments for TRS.

Polypharmacy to Clozapine Monotherapy in Treatment-Resistant Schizophrenia: A Case Report and Review of the Literature

This case report discusses a 25-year-old Middle Eastern female with a 14-year history of schizophrenia, managed as an inpatient for nearly eight years. Initially referred to a psychiatrist at age 12, with one-year-long concerns about preoccupation with the idea of having a serious illness, depressed mood, decreased appetite, social withdrawal, and aggression, she underwent multiple admissions, various medication combinations, and electroconvulsive therapy but remained resistant to treatment until clozapine monotherapy was initiated in 2023. After starting clozapine, improvements were noted in speech, communication, and eye contact, though negative symptoms and bouts of aggression persisted. This case highlights the efficacy of clozapine monotherapy in managing treatment-resistant schizophrenia after years of ineffective polypharmacy treatment. The importance of clozapine in treating treatment-resistant schizophrenia cannot be understated. Despite its efficacy, clozapine is often underutilised globally due to concerns about adverse effects and the need for blood monitoring, leading to the overuse of antipsychotic polypharmacy. This polypharmacy is associated with higher adverse event rates, increased costs, and uncertain long-term safety. This case report demonstrates the successful management of treatment-resistant schizophrenia with clozapine monotherapy. The patient's significant improvement supports the need to prioritise clozapine, highlighting its benefits over polypharmacy and advocating for its broader use to enhance patient outcomes.

Elevated intrinsic cortical curvature in treatment-resistant schizophrenia: Evidence of structural deformation in functional connectivity areas and comparison with alternate indices of structure

BACKGROUND

Research suggests structural and connectivity abnormalities in patients with treatment-resistant schizophrenia (TRS) compared to first-line responders and healthy-controls. However, measures of these abnormalities are often influenced by external factors like nicotine and antipsychotics, limiting their clinical utility. Intrinsic-cortical-curvature (ICC) presents a millimetre-scale measure of brain gyrification, highly sensitive to schizophrenia differences, and associated with TRS-like traits in early stages of the disorder. Despite this evidence, ICC in TRS remains unexplored. This study investigates ICC as a marker for treatment resistance in TRS, alongside structural indices for comparison.

METHODS

We assessed ICC in anterior cingulate, dorsolateral prefrontal, temporal, and parietal cortices of 38 first-line responders, 30 clozapine-resistant TRS, 37 clozapine-responsive TRS, and 52 healthy-controls. For comparative purposes, Fold and Curvature indices were also analyzed.

RESULTS

Adjusting for age, sex, nicotine-use, and chlorpromazine equivalence, principal findings indicate ICC elevations in the left hemisphere dorsolateral prefrontal (p < 0.001, η2partial = 0.142) and temporal cortices (LH p = 0.007, η2partial = 0.060; RH p = 0.011, η2partial = 0.076) of both TRS groups, and left anterior cingulate cortex of clozapine-resistant TRS (p = 0.026, η2partial = 0.065), compared to healthy-controls. Elevations that correlated with reduced cognition (p = 0.001) and negative symptomology (p < 0.034) in clozapine-resistant TRS. Fold and Curvature indices only detected group differences in the right parietal cortex, showing interactions with age, sex, and nicotine use. ICC showed interactions with age.

CONCLUSION

ICC elevations were found among patients with TRS, and correlated with symptom severity. ICCs relative independence from sex, nicotine-use, and antipsychotics, may support ICC's potential as a viable marker for TRS, though age interactions should be considered.

Variation of Clozapine Use for Treatment of Schizophrenia: Evidence from Pennsylvania Medicaid and Dually Eligible Enrollees

While clozapine is the most effective antipsychotic treatment for treatment-resistant schizophrenia, it remains underutilized across the United States, warranting a more comprehensive understanding of variation in use at the county level, as well as characterization of existing prescribing patterns. Here, we examined both Medicaid and Medicare databases to (1) characterize temporal and geographic variation in clozapine prescribing and, (2) identify patient-level characteristics associated with clozapine use. We included Medicaid and Fee for Service Medicare data in the state of Pennsylvania from January 1, 2013, through December 31, 2019. We focused on individuals with continuous enrollment, schizophrenia diagnosis, and multiple antipsychotic trials. Geographic variation was examined across counties of Pennsylvania. Regression models were constructed to determine demographic and clinical characteristics associated with clozapine use. Out of 8,255 individuals who may benefit from clozapine, 642 received treatment. We observed high medication burden, overall, including multiple antipsychotic trials. We also identified variation in clozapine use across regions in Pennsylvania with a disproportionate number of prescribers in urban areas and several counties with no identified clozapine prescribers. Finally, demographic, and clinical determinants of clozapine use were observed including less use in people identified as non-Hispanic Black, Hispanic, or with a substance use disorder. In addition, greater medical comorbidity was associated with increased clozapine use. Our work leveraged both Medicaid and Medicare data to characterize and surveil clozapine prescribing. Our findings support efforts monitor disparities and opportunities for the optimization of clozapine within municipalities to enhance clinical outcomes.

Pharmacokinetic/pharmacodynamic modeling of cortical dopamine concentrations after quetiapine lipid core nanocapsules administration to schizophrenia phenotyped rats

Schizophrenia (SCZ) response to pharmacological treatment is highly variable. Quetiapine (QTP) administered as QTP lipid core nanocapsules (QLNC) has been shown to modulate drug delivery to the brain of SCZ phenotyped rats (SPR). In the present study, we describe the brain concentration-effect relationship after administrations of QTP as a solution or QLNC to SPR and naïve animals. A semimechanistic pharmacokinetic (PK) model describing free QTP concentrations in the brain was linked to a pharmacodynamic (PD) model to correlate the drug kinetics to changes in dopamine (DA) medial prefrontal cortex extracellular concentrations determined by intracerebral microdialysis. Different structural models were investigated to fit DA concentrations after QTP dosing, and the final model describes the synthesis, release, and elimination of DA using a pool compartment. The results show that nanoparticles increase QTP brain concentrations and DA peak after drug dosing to SPR. To the best of our knowledge, this is the first study that combines microdialysis and PK/PD modeling in a neurodevelopmental model of SCZ to investigate how a nanocarrier can modulate drug PK and PD, contributing to the development of new treatment strategies for SCZ.

Alteration of DNA Methylation and Epigenetic Scores Associated With Features of Schizophrenia and Common Variant Genetic Risk

BACKGROUND

Unpacking molecular perturbations associated with features of schizophrenia is a critical step toward understanding phenotypic heterogeneity in this disorder. Recent epigenome-wide association studies have uncovered pervasive dysregulation of DNA methylation in schizophrenia; however, clinical features of the disorder that account for a large proportion of phenotypic variability are relatively underexplored.

METHODS

We comprehensively analyzed patterns of DNA methylation in a cohort of 381 individuals with schizophrenia from the deeply phenotyped Australian Schizophrenia Research Bank. Epigenetic changes were investigated in association with cognitive status, age of onset, treatment resistance, Global Assessment of Functioning scores, and common variant polygenic risk scores for schizophrenia. We subsequently explored alterations within genes previously associated with psychiatric illness, phenome-wide epigenetic covariance, and epigenetic scores.

RESULTS

Epigenome-wide association studies of the 5 primary traits identified 662 suggestively significant (p < 6.72 × 10-5) differentially methylated probes, with a further 432 revealed after controlling for schizophrenia polygenic risk on the remaining 4 traits. Interestingly, we uncovered many probes within genes associated with a variety of psychiatric conditions as well as significant epigenetic covariance with phenotypes and exposures including acute myocardial infarction, C-reactive protein, and lung cancer. Epigenetic scores for treatment-resistant schizophrenia strikingly exhibited association with clozapine administration, while epigenetic proxies of plasma protein expression, such as CCL17, MMP10, and PRG2, were associated with several features of schizophrenia.

CONCLUSIONS

Our findings collectively provide novel evidence suggesting that several features of schizophrenia are associated with alteration of DNA methylation, which may contribute to interindividual phenotypic variation in affected individuals.

Comparative Study of the Efficacy and Side Effects of Brand-Name and Generic Clozapine for Long-Term Maintenance Treatment Among Korean Patients With Schizophrenia: A Retrospective Naturalistic Mirror-Image Study

OBJECTIVE

Clozapine is considered the most reliable drug for treatment-resistant schizophrenia. In 2014, a generic formulation of clozapine (Clzapine) was introduced in Korea. This study was performed to provide clinical information regarding the use of clozapine and to compare efficacy and tolerability when converting from the brand-name formulation (Clozaril) to the generic formulation during longterm maintenance treatment among Korean patients with schizophrenia.

METHODS

This mirror-image study retrospectively investigated the electronic medical records of patients who had switched from Clozaril to Clzapine with a ≥1-year duration for each formulation. Clinical data were collected, including information regarding clozapine use, psychiatric hospitalization, co-medications, and blood test findings. Data before and after the switch were compared using paired t-tests.

RESULTS

Among 332 patients, the mean 1-year dosages were 233.32±149.35 mg/day for Clozaril and 217.36±136.66 mg/day for Clzapine. The mean clozapine concentration-to-dose ratios were similar before and after the switch (Clozaril, 1.33±0.68; Clzapine, 1.26±0.80). Switching from Clozaril to Clzapine resulted in no significant differences in the hospitalization rate, hospitalization duration, or laboratory findings (liver function parameters, serum cholesterol level, and serum glucose level). Equivalent doses of co-prescribed antidepressants were decreased, but concomitant medications otherwise showed no significant differences.

CONCLUSION

Clinical efficacy and tolerability appear comparable when switching to Clzapine during clozapine maintenance treatment. This study offers descriptive real-world clinical insights into clozapine maintenance treatment in Korea, thereby providing patients with more treatment options and contributing to the development of maintenance guidelines tailored to the Korean population.

Development of an individualized risk calculator of treatment resistance in patients with first-episode psychosis (TRipCal) using automated machine learning: a 12-year follow-up study with clozapine prescription as a proxy indicator

About 15-40% of patients with schizophrenia are treatment resistance (TR) and require clozapine. Identifying individuals who have higher risk of development of TR early in the course of illness is important to provide personalized intervention. A total of 1400 patients with FEP enrolled in the early intervention for psychosis service or receiving the standard psychiatric service between July 1, 1998, and June 30, 2003, for the first time were included. Clozapine prescriptions until June 2015, as a proxy of TR, were obtained. Premorbid information, baseline characteristics, and monthly clinical information were retrieved systematically from the electronic clinical management system (CMS). Training and testing samples were established with random subsampling. An automated machine learning (autoML) approach was used to optimize the ML algorithm and hyperparameters selection to establish four probabilistic classification models (baseline, 12-month, 24-month, and 36-month information) of TR development. This study found 191 FEP patients (13.7%) who had ever been prescribed clozapine over the follow-up periods. The ML pipelines identified with autoML had an area under the receiver operating characteristic curve ranging from 0.676 (baseline information) to 0.774 (36-month information) in predicting future TR. Features of baseline information, including schizophrenia diagnosis and age of onset, and longitudinal clinical information including symptoms variability, relapse, and use of antipsychotics and anticholinergic medications were important predictors and were included in the risk calculator. The risk calculator for future TR development in FEP patients (TRipCal) developed in this study could support the continuous development of data-driven clinical tools to assist personalized interventions to prevent or postpone TR development in the early course of illness and reduce delay in clozapine initiation.

Vaccination and clozapine use: a systematic review and an analysis of the VAERS database

In the context of COVID-19 concerns related to the potential interactions between clozapine and vaccination arose. With the ultimate goal of deriving recommendations for clinical practice, we systematically reviewed the current evidence regarding altered vaccine effectiveness in clozapine-treated patients and safety aspects of vaccination, such as haematological changes and the impact of vaccines on clozapine blood levels, in clozapine-treated patients. A systematic PRISMA-conform literature search of four databases (PubMed, PsycINFO, EMBASE and Cochrane Library) complemented by a case-by-case analysis of the Vaccine Adverse Event Reporting System (VAERS) database was performed. We then systematically appraised the joint evidence and tried to derive recommendations for clinical practice. 14 records were included in this analysis. These records consisted of 5 original articles and 9 case reports. Among the original articles, two studies provided data on the association between clozapine use and antibody responses to vaccination, both indicating that clozapine use in schizophrenia may be associated with reduced levels of immunoglobulins. Additionally, three studies examined vaccine safety in clozapine-treated patients, with no clinically significant adverse effects directly attributable to the interplay between vaccinations and clozapine. VAERS Analysis encompassed 137 reports and showed no consistent evidence of an increased risk for clozapine blood level increases or adverse events. We found no evidence indicating that clozapine impairs the effectiveness of vaccines. Moreover, no serious safety concerns seem to apply when patients on clozapine are receiving vaccines. However, it is crucial to acknowledge that data on the interaction between clozapine and vaccines remain limited.

Negative symptoms and cognitive impairment are associated with distinct motivational deficits in treatment resistant schizophrenia

BACKGROUND

Motivational deficits are a central feature of the negative syndrome in schizophrenia. They have consistently been associated with reduced willingness to expend physical effort in return for monetary rewards on effort based decision making (EBDM) paradigms. Nevertheless, the mechanisms underlying such altered performance are not well characterised, and it remains unclear if they are driven purely by negative symptoms, or also in part by cognitive impairment, antipsychotic treatment or even positive symptoms. Here we investigated the impact of all these factors using a paradigm that has not previously been used to measure EBDM in schizophrenia.

METHODS

Forty treatment resistant schizophrenia (TRS) patients on clozapine and matched controls (N = 80) completed a well validated EBDM task which offers monetary rewards in return for physical effort. Choice and reaction time data was analysed using logistic regressions, as well as Bayesian hierarchical drift diffusion modelling (HDDM). Behavioural parameters were compared between groups and their association with negative symptoms, cognitive function and serum clozapine levels were assessed.

RESULTS

Overall, TRS patients accepted significantly less offers than controls during effort-based decision making, suggesting they were less motivated. They demonstrated reduced sensitivity to increasing rewards, but surprisingly were also less averse to increasing effort. Despite a positive correlation between negative symptoms and cognitive function in TRS, reward sensitivity was associated only with cognitive performance. In contrast, reduced effort aversion correlated with negative symptom severity. Clozapine levels and positive symptoms were not associated with either behavioural parameter.

CONCLUSION

Motivational deficits in TRS are characterised by both diminished reward sensitivity and reduced effort aversion during EBDM. Cognitive dysfunction and negative symptom severity account for distinct aspects of these behavioural changes, despite positive associations between themselves. Overall, these findings demonstrate that negative symptoms and cognitive impairment have significant independent contributions to EBDM in TRS, thereby opening the possibility of individualised treatment targeting these mechanisms to improve motivation.

A systematic review of the role of clozapine for severe borderline personality disorder

RATIONALE

Clozapine is a unique medication with a potential role in the treatment of severe borderline personality disorder (BPD).

OBJECTIVES

The review examines the effectiveness of clozapine as a medication for management for severe BPD with high risk of suicide, violence or imprisonment, and aims to help guide clinical practice in managing severe BPD.

METHODS

A database search of the terms "Clozapine" AND "BPD"; "Antipsychotics" AND "BPD"; "Clozapine" AND "Borderline Personality Disorder"; and "Antipsychotics" AND "Borderline Personality Disorder" were performed in CINAHL, Cochrane Library, Embase, Medline, PsychINFO, PubMed, and Web of Science. Full-text articles of clinical clozapine use for BPD were included for review.

RESULTS

A total of 24 articles consisting of 1 randomised control trial, 10 non-controlled trials, and 13 case reports were identified. Most of the studies reported benefits from clozapine when used for severe BPD. Many of the studies focused on clozapine use in BPD patients at high risk of suicide. Results from these non-controlled and case reports support the use of clozapine in patients with severe BPD at high risk of suicide.

CONCLUSION

There may be a role for clozapine in treating severe treatment refractory BPD, especially for those patients at high risk of suicide and frequent hospitalisations.

Early neutrophil trajectory following clozapine may predict clozapine response - Results from an observational study using electronic health records

BACKGROUND

Clozapine has unique effectiveness in treatment-resistant schizophrenia and is known to cause immunological side-effects. A transient spike in neutrophils commonly occurs in the first weeks of clozapine therapy. There is contradictory evidence in the literature as to whether neutrophil changes with clozapine are linked to treatment response.

AIMS

The current study aims to further examine the neutrophil changes in response to clozapine and explore any association between neutrophil trajectory and treatment response.

METHODS

A retrospective cohort study of patients undergoing their first treatment with clozapine and continuing for at least 2 years identified 425 patients (69% male/31% female). Neutrophil counts at baseline, 3 weeks and 1 month were obtained predominantly by linkage with data from the clozapine monitoring service. Clinical Global Impression- Severity (CGI-S) was rated from case notes at the time of clozapine initiation and at 2 years. Latent class growth analysis (LCGA) was performed to define distinct trajectories of neutrophil changes during the first month of treatment. Logistic regression was then conducted to investigate for association between the trajectory of neutrophil count changes in month 1 and clinical response at 2 years as well as between baseline neutrophil count and response.

RESULTS

Of the original cohort, 397 (93%) patients had useable neutrophil data during the first 6 weeks of clozapine treatment. LCGA revealed significant differences in neutrophil trajectories with a three-class model being the most parsimonious. The classes had similar trajectory profiles but differed primarily on overall neutrophil count: with low, high-normal and high neutrophil classes, comprising 52%, 40% and 8% of the sample respectively. Membership of the high-normal group was associated with significantly increased odds of a positive response to clozapine, as compared to the low neutrophil group [Odds ratio (OR) = 2.10, p-value = 0.002; 95% confidence interval (95% CI) = 1.31-3.36]. Baseline neutrophil count was a predictor of response to clozapine at 2 years, with counts of ≥5 × 109/l significantly associated with positive response (OR = 1.60, p-value = 0.03; 95% CI = 1.03-2.49).

CONCLUSIONS

Our data are consistent with the hypothesis that patients with low-level inflammation, reflected in a high-normal neutrophil count, are more likely to respond to clozapine, raising the possibility that clozapine exerts its superior efficacy via immune mechanisms.

Toxicity and Adverse Effects in Clozapine-Related Presentations to a Medical Toxicology Service in Western Sydney

BACKGROUND

Clozapine is an anti-psychotic agent, reserved for treatment-resistant schizophrenia, with demonstrated efficacy in an otherwise therapeutically challenging patient population. We aimed to review the full spectrum casemix of clozapine presentations to our tertiary toxicology service.

METHODS

In this retrospective study, we reviewed consecutive clozapine related toxicity presentations to a tertiary medical toxicology inpatient and consultation service-including deliberate self-poisoning (DSP), adverse drug reaction (ADR), recreational use, and therapeutic misadventure over a 10-year period from 2011 to 2021. Data were extracted for demographics, ingested dose, exposure characteristics, and patient outcome.

RESULTS

We identified 83 patients with clozapine-related presentations over the 10-year period. Twenty-two patients were excluded. Of the remaining 61 patients, 28 patients presented with DSP, 20 patients with accidental overdose, and 13 patients with an ADR; no patients presented with recreational use. It was noted that ADRs were largely idiosyncratic reactions and not always related to dose adjustments. In the context of therapeutic misadventure and DSP, we noted that a lower mean dose achieved a higher poison severity score (PSS) in clozapine-naive patients when compared to those patients on regular clozapine.

CONCLUSIONS

The presentation of clozapine-related toxicity differs depending on the modality of ingestion, whether DSP, accidental, or as a result of ADR. Patients naive to clozapine therapy tend to experience higher PSS with lower doses ingested either in a deliberate self-poisoning or accidental ingestion context. This is likely due to tolerance to the sedative properties of clozapine. No patients manifested clinical toxicity greater than 8 hours after ingestion, with an observation period of 6 hours accurately identifying toxicity in most patients.

fMRI connectivity as a biomarker of antipsychotic treatment response: A systematic review

BACKGROUND

Antipsychotic drugs are the first-choice therapy for psychotic episodes, but antipsychotic treatment response (AP-R) is unpredictable and only becomes clear after weeks of therapy. A biomarker for AP-R is currently unavailable. We reviewed the evidence for the hypothesis that functional magnetic resonance imaging functional connectivity (fMRI-FC) is a predictor of AP-R or could serve as a biomarker for AP-R in psychosis.

METHOD

A systematic review of longitudinal fMRI studies examining the predictive performance and relationship between FC and AP-R was performed following PRISMA guidelines. Technical and clinical aspects were critically assessed for the retrieved studies. We addressed three questions: Q1) is baseline fMRI-FC related to subsequent AP-R; Q2) is AP-R related to a change in fMRI-FC; and Q3) can baseline fMRI-FC predict subsequent AP-R?

RESULTS

In total, 28 articles were included. Most studies were of good quality. fMRI-FC analysis pipelines included seed-based-, independent component- / canonical correlation analysis, network-based statistics, and graph-theoretical approaches. We found high heterogeneity in methodological approaches and results. For Q1 (N = 17) and Q2 (N = 18), the most consistent evidence was found for FC between the striatum and ventral attention network as a potential biomarker of AP-R. For Q3 (N = 9) accuracy's varied form 50 till 93%, and prediction models were based on FC between various brain regions.

CONCLUSION

The current fMRI-FC literature on AP-R is hampered by heterogeneity of methodological approaches. Methodological uniformity and further improvement of the reliability and validity of fMRI connectivity analysis is needed before fMRI-FC analysis can have a place in clinical applications of antipsychotic treatment.

Schizophrenia-associated somatic copy-number variants from 12,834 cases reveal recurrent NRXN1 and ABCB11 disruptions

While germline copy-number variants (CNVs) contribute to schizophrenia (SCZ) risk, the contribution of somatic CNVs (sCNVs)-present in some but not all cells-remains unknown. We identified sCNVs using blood-derived genotype arrays from 12,834 SCZ cases and 11,648 controls, filtering sCNVs at loci recurrently mutated in clonal blood disorders. Likely early-developmental sCNVs were more common in cases (0.91%) than controls (0.51%, p = 2.68e-4), with recurrent somatic deletions of exons 1-5 of the NRXN1 gene in five SCZ cases. Hi-C maps revealed ectopic, allele-specific loops forming between a potential cryptic promoter and non-coding cis-regulatory elements upon 5' deletions in NRXN1. We also observed recurrent intragenic deletions of ABCB11, encoding a transporter implicated in anti-psychotic response, in five treatment-resistant SCZ cases and showed that ABCB11 is specifically enriched in neurons forming mesocortical and mesolimbic dopaminergic projections. Our results indicate potential roles of sCNVs in SCZ risk.

The Neurobiological Underpinnings of Obsessive-Compulsive Symptoms in Psychosis, Translational Issues for Treatment-Resistant Schizophrenia

Almost 25% of schizophrenia patients suffer from obsessive-compulsive symptoms (OCS) considered a transdiagnostic clinical continuum. The presence of symptoms pertaining to both schizophrenia and obsessive-compulsive disorder (OCD) may complicate pharmacological treatment and could contribute to lack or poor response to the therapy. Despite the clinical relevance, no reviews have been recently published on the possible neurobiological underpinnings of this comorbidity, which is still unclear. An integrative view exploring this topic should take into account the following aspects: (i) the implication for glutamate, dopamine, and serotonin neurotransmission as demonstrated by genetic findings; (ii) the growing neuroimaging evidence of the common brain regions and dysfunctional circuits involved in both diseases; (iii) the pharmacological modulation of dopaminergic, serotoninergic, and glutamatergic systems as current therapeutic strategies in schizophrenia OCS; (iv) the recent discovery of midbrain dopamine neurons and dopamine D1- and D2-like receptors as orchestrating hubs in repetitive and psychotic behaviors; (v) the contribution of N-methyl-D-aspartate receptor subunits to both psychosis and OCD neurobiology. Finally, we discuss the potential role of the postsynaptic density as a structural and functional hub for multiple molecular signaling both in schizophrenia and OCD pathophysiology.

Polygenic overlap with body-mass index improves prediction of treatment-resistant schizophrenia

Treatment resistant schizophrenia (TRS) is characterized by repeated treatment failure with antipsychotics. A recent genome-wide association study (GWAS) of TRS showed a polygenic architecture, but no significant loci were identified. Clozapine is shown to be the superior drug in terms of clinical effect in TRS; at the same time it has a serious side effect profile, including weight gain. Here, we sought to increase power for genetic discovery and improve polygenic prediction of TRS, by leveraging genetic overlap with Body Mass Index (BMI). We analysed GWAS summary statistics for TRS and BMI applying the conditional false discovery rate (cFDR) framework. We observed cross-trait polygenic enrichment for TRS conditioned on associations with BMI. Leveraging this cross-trait enrichment, we identified 2 novel loci for TRS at cFDR <0.01, suggesting a role of MAP2K1 and ZDBF2. Further, polygenic prediction based on the cFDR analysis explained more variance in TRS when compared to the standard TRS GWAS. These findings highlight putative molecular pathways which may distinguish TRS patients from treatment responsive patients. Moreover, these findings confirm that shared genetic mechanisms influence both TRS and BMI and provide new insights into the biological underpinnings of metabolic dysfunction and antipsychotic treatment.

A new synthetic ultrasound-assisted method for dibenzoepines

In this study, we have developed a new ultrasonic synthesis method of dibenzoepines using olanzapine and quetiapine, which are well-known drugs for the treatment of schizophrenia and bipolar disorder. The method is based on the N-alkylation reaction of the piperazine fragment in tricyclic compounds with methyl iodide or 2-(2-chloroethoxy)ethanol as the alkylating agent, respectively. The synthesis reactions were carried out in an ultrasonic bath with solvents such as acetonitrile or dimethylformamide in the presence of potassium or sodium carbonate or sodium hydroxide and metal-free, ecological phase transfer catalyst at a temperature of 40-50 °C. This allowed us to obtain olanzapine in 1 h (Y = 67%), and quetiapine in 3 h (Y = 72%). An ultrasonic reactor (Qsonica Q700) was used in the synthesis of olanzapine and made it possible to shorten the reaction time to 10 min and obtain 90% yield with very high purity. The developed method allows obtaining compounds in mild conditions and in a short time, thanks to which the process is more ecological than others described in the literature.

Second to none: rationale, timing, and clinical management of clozapine use in schizophrenia

Despite its enduring relevance as the single most effective and important evidence-based treatment for schizophrenia, underutilization of clozapine remains considerable. To a substantial degree, this is attributable to a reluctance of psychiatrists to offer clozapine due to its relatively large side-effect burden and the complexity of its use. This underscores the necessity for continued education regarding both the vital nature and the intricacies of clozapine treatment. This narrative review summarizes all clinically relevant areas of evidence, which support clozapine's wide-ranging superior efficacy - for treatment-resistant schizophrenia (TRS) and beyond - and make its safe use eminently feasible. Converging evidence indicates that TRS constitutes a distinct albeit heterogeneous subgroup of schizophrenias primarily responsive to clozapine. Most importantly, the predominantly early onset of treatment resistance and the considerable decline in response rates associated with its delayed initiation make clozapine an essential treatment option throughout the course of illness, beginning with the first psychotic episode. To maximize patients' benefits, systematic early recognition efforts based on stringent use of TRS criteria, a timely offer of clozapine, thorough side-effect screening and management as well as consistent use of therapeutic drug monitoring and established augmentation strategies for suboptimal responders are crucial. To minimize permanent all-cause discontinuation, re-challenges after neutropenia or myocarditis should be considered. Owing to clozapine's unique efficacy, comorbid conditions including substance use and most somatic disorders should not dissuade but rather encourage clinicians to consider clozapine. Moreover, treatment decisions need to be informed by the late onset of clozapine's full effects, which for reduced suicidality and mortality rates may not even be readily apparent. Overall, the singular extent of its efficacy combined with the high level of patient satisfaction continues to distinguish clozapine from all other available antipsychotics.

Lurasidone Augmentation of Clozapine in Refractory Schizophrenia: A Case Series

PURPOSE

Clozapine represents the criterion standard therapy for patients with treatment-resistant schizophrenia. Unfortunately, a significant percentage of such patients are also partial responders to clozapine. Consequently, several augmentation strategies have been proposed with various and sometimes controversial efficacy. Among these add-on treatments, lurasidone has been recently introduced and could represent a potential option, especially for the additional positive effect on cognitive symptoms.

METHODS

This case series aims to determine possible advantages of lurasidone augmentation in four patients treated with clozapine, who were diagnosed with treatment-resistant schizophrenia. Positive and Negative Syndrome Scales were used to evaluate psychopathology, the Udvalg for Kliniske Undersøgelser scale for tolerability and safety.

FINDING

All patients achieved a significant reduction of both positive and negative symptoms, with no significant adverse effects to be reported.

IMPLICATIONS

Our observation suggests that lurasidone can lead to clinically significant improvements in psychopathology with a good tolerability profile when added to clozapine.

Clozapine rechallenge or continuation despite neutropenia or agranulocytosis using colony-stimulating factor: A systematic review

OBJECTIVES

Rechallenge/continuation of clozapine in association with colony-stimulating factors (CSFs) following neutropenia/agranulocytosis has been reported, but many questions remain unanswered about efficacy and safety. This systematic review aims to assess the efficacy and safety of rechallenging/continuing clozapine in patients following neutropenia/agranulocytosis using CSFs.

METHODS

MEDLINE, Embase, PsycInfo, and Web of Science databases were searched from inception date to July 31, 2022. Articles screening and data extraction were realized independently by two reviewers, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 systematic review guidance. Included articles had to report on at least one case where clozapine was rechallenged/continued using CSFs despite previous neutropenia/agranulocytosis.

RESULTS

Eight hundred forty articles were retrieved; 34 articles met the inclusion criteria, totaling 59 individual cases. Clozapine was successfully rechallenged/continued in 76% of patients for an average follow-up period of 1.9 years. There was a trend toward better efficacy reported in case reports/series, compared with consecutive case series (overall success rates of 84% and 60%, respectively, p-value = 0.065). Two administration strategies were identified, "as-needed" and prophylactic, both yielding similar success rates (81% and 80%, respectively). Only mild and transient adverse events were documented.

CONCLUSIONS

Although limited by the relatively small number of published cases, factors such as time of onset to first neutropenia and severity of the episode did not seem to impact the outcome of a subsequent clozapine rechallenge using CSFs. While the efficacy of this strategy remains to be further adequately evaluated in more rigorous study designs, its long-term innocuity warrants considering its use more proactively in the management of clozapine hematological adverse events as to maintain this treatment for as many individuals as possible.

Predicting treatment resistance from first-episode psychosis using routinely collected clinical information

Around a quarter of people who experience a first episode of psychosis (FEP) will develop treatment-resistant schizophrenia (TRS), but there are currently no established clinically useful methods to predict this from baseline. We aimed to explore the predictive potential for clozapine use as a proxy for TRS of routinely collected, objective biomedical predictors at FEP onset, and to externally validate the model in a separate clinical sample of people with FEP. We developed and externally validated a forced-entry logistic regression risk prediction Model fOr cloZApine tReaTment, or MOZART, to predict up to 8-year risk of clozapine use from FEP using routinely recorded information including age, sex, ethnicity, triglycerides, alkaline phosphatase levels, and lymphocyte counts. We also produced a least-absolute shrinkage and selection operator (LASSO) based model, additionally including neutrophil count, smoking status, body mass index, and random glucose levels. The models were developed using data from two UK psychosis early intervention services (EIS) and externally validated in another UK EIS. Model performance was assessed via discrimination and calibration. We developed the models in 785 patients, and validated externally in 1,110 patients. Both models predicted clozapine use well at internal validation (MOZART: C 0.70; 95%CI 0.63,0.76; LASSO: 0.69; 95%CI 0.63,0.77). At external validation, discrimination performance reduced (MOZART: 0.63; 0.58,0.69; LASSO: 0.64; 0.58,0.69) but recovered after re-estimation of the lymphocyte predictor (C: 0.67; 0.62,0.73). Calibration plots showed good agreement between observed and predicted risk in the forced-entry model. We also present a decision-curve analysis and an online data visualisation tool. The use of routinely collected clinical information including blood-based biomarkers taken at FEP onset can help to predict the individual risk of clozapine use, and should be considered equally alongside other potentially useful information such as symptom scores in large-scale efforts to predict psychiatric outcomes.

Antipsychotic prescribing practices for outpatients with schizophrenia and reasons for non-clozapine treatment - Data from a Danish quality assessment audit

BACKGROUND

Clozapine is the gold standard for treating treatment-resistant schizophrenia (TRS) although widely underutilised. Both organisational, patient- and clinician related reasons for the underutilisation have been reported, however, the clinical impact of either in real-world settings is not fully elucidated.

AIM

This audit aimed to evaluate the local antipsychotic (AP) prescribing practices for outpatients with schizophrenia and to assess the spectrum and prevalence of journalised reasons for non-clozapine treatment amongst eligible outpatients.

METHODS

Data on demographics, current and former AP treatments, as well as documented reasons for non-clozapine treatment, was extracted through chart audit.

RESULTS

Of the 668 affiliated outpatients with schizophrenia, 43% were treated with AP polytherapy (APP) and 19.6% with clozapine. The most prevalent reason for clozapine discontinuation was related to side effects whereas the most prevalent reason for refusal or omission of clozapine treatment was related to the associated monitoring regimen.

CONCLUSIONS

This audit showed that APP prescribing is a highly prevalent practice in our services when treating outpatients with schizophrenia and that clozapine is underutilised in a 'last resort' manner. The blood-monitoring regimen associated with clozapine treatment was found to be an important factor in the underutilisation. It seemed, however, that the monitoring constituted a barrier for different reasons, requiring different approaches to remedy. Future studies, directly involving both patients and clinicians in the identification and management of the most clinically relevant barriers and their corresponding facilitators, are warranted.

De Novo Seizures, Obsessive Compulsive Symptoms and Neutropenias in Patients on Clozapine: A Retrospective Cohort Study

BACKGROUND

Clozapine has well-documented inter-ethnic variations in pharmacokinetics. There is a paucity of data about clozapine use and associated adverse events such as seizures, obsessive compulsive symptoms, neutropenia, and agranulocytosis, from India.

METHODS

This retrospective cohort study followed up 228 patients initiated on clozapine in a tertiary care referral center in India for an average of 10 years. We calculated incidence rates of new-onset seizures, new-onset obsessive compulsive symptoms, agranulocytosis, and neutropenia. We collected data on doses of clozapine used and serum assays and calculated concentration-to-dose (C/D) ratios. We also collected relevant clinical details about clozapine-induced seizures.

RESULTS

In the sample, 16.8% had new-onset seizures, 12.3% had new-onset OC symptoms, 2.7% had neutropenia, and 0.9% had agranulocytosis. The mean C/D ratio was 2.09 (SD = 1.8). Almost half (46.3%) of available serum assays were in the supra-therapeutic range. Seizures were associated with a higher clozapine dose at one year (OR = 1.003; 95%CI = 1.000-1.006; P value = 0.045) and the presence of positive psychotic symptoms at one year (OR = 4.214; 95%CI = 1.894-9.373; P < 0.001).

CONCLUSION

Compared to existing literature, Indians have a higher rate of clozapine- related seizures and need lower doses to reach therapeutic serum levels.

The Strategy of Targeting Peroxisome Proliferator-Activated Receptor (PPAR) in the Treatment of Neuropsychiatric Disorders

Peroxisome proliferator-activated receptors (PPARs) are nonsteroid nuclear receptors and transcription factors that regulate several neuroinflammatory and metabolic processes, recently involved in several neuropsychiatric conditions, including Alzheimer's disease, Parkinson's disease, major depressive disorder, post-traumatic stress disorder (PTSD), schizophrenia spectrum disorders, and autism spectrum disorders. PPARs are ligand-activated receptors that, following stimulation, induce neuroprotective effects by decreasing neuroinflammatory processes through inhibition of the nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) expression and consequent suppression of pro-inflammatory cytokine production. PPARs heterodimerize with the retinoid X-receptor (RXR) and bind to PPAR-responsive regulatory elements (PPRE) in the promoter region of target genes involved in lipid metabolism, synthesis of cholesterol, catabolism of amino acids, and inflammation. Interestingly, PPARs are considered functionally part of the extended endocannabinoid (eCB) system that includes the classic eCB, anandamide, which act at cannabinoid receptor types 1 (CB1) and 2 (CB2) and are implicated in the pathophysiology of stress-related neuropsychiatric disorders. In preclinical studies, PPAR stimulation improves anxiety and depression-like behaviors by enhancing neurosteroid biosynthesis. The peculiar functional role of PPARs by exerting anti-inflammatory and neuroprotective effects and their expression localization in neurons and glial cells of corticolimbic circuits make them particularly interesting as novel therapeutic targets for several neuropsychiatric disorders characterized by underlying neuroinflammatory/neurodegenerative mechanisms. Herein, we discuss the pathological hallmarks of neuropsychiatric conditions associated with neuroinflammation, as well as the pivotal role of PPARs with a special emphasis on the subtype alpha (PPAR-α) as a suitable molecular target for therapeutic interventions.

A growing understanding of the role of muscarinic receptors in the molecular pathology and treatment of schizophrenia

Pre-clinical models, postmortem and neuroimaging studies all support a role for muscarinic receptors in the molecular pathology of schizophrenia. From these data it was proposed that activation of the muscarinic M1 and/or M4 receptor would reduce the severity of the symptoms of schizophrenia. This hypothesis is now supported by results from two clinical trials which indicate that activating central muscarinic M1 and M4 receptors can reduce the severity of positive, negative and cognitive symptoms of the disorder. This review will provide an update on a growing body of evidence that argues the muscarinic M1 and M4 receptors have critical roles in CNS functions that are dysregulated by the pathophysiology of schizophrenia. This realization has been made possible, in part, by the growing ability to visualize and quantify muscarinic M1 and M4 receptors in the human CNS using molecular neuroimaging. We will discuss how these advances have provided evidence to support the notion that there is a sub-group of patients within the syndrome of schizophrenia that have a unique molecular pathology driven by a marked loss of muscarinic M1 receptors. This review is timely, as drugs targeting muscarinic receptors approach clinical use for the treatment of schizophrenia and here we outline the background biology that supported development of such drugs to treat the disorder.

Decreased cortical gyrification and surface area in the left medial parietal cortex in patients with treatment-resistant and ultratreatment-resistant schizophrenia

AIM

Validating the vulnerabilities and pathologies underlying treatment-resistant schizophrenia (TRS) is an important challenge in optimizing treatment. Gyrification and surface area (SA), reflecting neurodevelopmental features, have been linked to genetic vulnerability to schizophrenia. The aim of this study was to identify gyrification and SA abnormalities specific to TRS.

METHODS

We analyzed 3T magnetic resonance imaging findings of 24 healthy controls (HCs), 20 responders to first-line antipsychotics (FL-Resp), and 41 patients with TRS, including 19 clozapine responders (CLZ-Resp) and 22 FL- and clozapine-resistant patients (patients with ultratreatment-resistant schizophrenia [URS]). The local gyrification index (LGI) and associated SA were analyzed across groups. Diagnostic accuracy was verified by receiver operating characteristic curve analysis.

RESULTS

Both CLZ-Resp and URS had lower LGI values than HCs (P = 0.041, Hedges g [g_H ] = 0.75; P = 0.013, g_H  = 0.96) and FL-Resp (P = 0.007, g_H  = 1.00; P = 0.002, g_H  = 1.31) in the left medial parietal cortex (Lt-MPC). In addition, both CLZ-Resp and URS had lower SA in the Lt-MPC than FL-Resp (P < 0.001, g_H  = 1.22; P < 0.001, g_H  = 1.75). LGI and SA were positively correlated in non-TRS (FL-Resp) (ρ = 0.64, P = 0.008) and TRS (CLZ-Resp + URS) (ρ = 0.60, P < 0.001). The areas under the receiver operating characteristic curve for non-TRS versus TRS with LGI and SA in the Lt-MPC were 0.79 and 0.85, respectively. SA in the Lt-MPC was inversely correlated with negative symptoms (ρ = -0.40, P = 0.018) and clozapine plasma levels (ρ = -0.35, P = 0.042) in TRS.

CONCLUSION

LGI and SA in the Lt-MPC, a functional hub in the default-mode network, were abnormally reduced in TRS compared with non-TRS. Thus, altered LGI and SA in the Lt-MPC might be structural features associated with genetic vulnerability to TRS.

Postsurgical morbidity and mortality favorably informs deep brain stimulation for new indications including schizophrenia and schizoaffective disorder

Background

Deep brain stimulation (DBS) shows promise for new indications like treatment-refractory schizophrenia in early clinical trials. In the first DBS clinical trial for treatment refractory schizophrenia, despite promising results in treating psychosis, one of the eight subjects experienced both a symptomatic hemorrhage and an infection requiring device removal. Now, ethical concerns about higher surgical risk in schizophrenia/schizoaffective disorder (SZ/SAD) are impacting clinical trial progress. However, insufficient cases preclude conclusions regarding DBS risk in SZ/SAD. Therefore, we directly compare adverse surgical outcomes for all surgical procedures between SZ/SAD and Parkinson's disease (PD) cases to infer relative surgical risk relevant to gauging DBS risks in subjects with SZ/SAD.

Design

In the primary analysis, we used browser-based statistical analysis software, TriNetX Live (trinetx.com TriNetX LLC, Cambridge, MA), for Measures of Association using the Z-test. Postsurgical morbidity and mortality after matching for ethnicity, over 39 risk factors, and 19 CPT 1003143 coded surgical procedures from over 35,000 electronic medical records, over 19 years, from 48 United States health care organizations (HCOs) through the TriNetX Research Network™. TriNetXis a global, federated, web-based health research network providing access and statistical analysis of aggregate counts of deidentified EMR data. Diagnoses were based on ICD-10 codes. In the final analysis, logistic regression was used to determine relative frequencies of outcomes among 21 diagnostic groups/cohorts being treated with or considered for DBS and 3 control cohorts.

Results

Postsurgical mortality was 1.01-4.11% lower in SZ/SAD compared to the matched PD cohort at 1 month and 1 year after any surgery, while morbidity was 1.91-2.73% higher and associated with postsurgical noncompliance with medical treatment. Hemorrhages and infections were not increased. Across the 21 cohorts compared, PD and SZ/SAD were among eight cohorts with fewer surgeries, nine cohorts with higher postsurgical morbidity, and fifteen cohorts within the control-group range for 1-month postsurgical mortality.

Conclusions

Given that the subjects with SZ or SAD, along with most other diagnostic groups examined, had lower postsurgical mortality than PD subjects, it is reasonable to apply existing ethical and clinical guidelines to identify appropriate surgical candidates for inclusion of these patient populations in DBS clinical trials.

Association of cortical thickness and cognition with schizophrenia treatment resistance

AIM

Approximately a third of patients with schizophrenia fail to adequately respond to antipsychotic medications, a condition known as treatment resistance (TR). We aimed to assess cognitive and cortical thickness deficits and their relationship to TR in schizophrenia.

METHOD

We recruited patients with schizophrenia (n = 127), including patients at treatment initiation (n = 45), treatment-responsive patients (n = 40) and TR patients (n = 42), and healthy controls (n = 83). Clinical symptoms, neurocognitive function, and structural images were assessed. We performed group comparisons, and explored association of cortical thickness and cognition with TR.

RESULTS

The TR patients showed significantly more severe clinical symptoms and cognitive impairment relative to the treatment-responsive group. Compared to healthy controls, 56 of 68 brain regions showed significantly reduced cortical thickness in patients with schizophrenia. Reductions in five regions were significantly associated with TR (reduction in TR relative to treatment-responsive patients), i.e. in the right caudal middle frontal gyrus, superior frontal cortex, fusiform gyrus, pars opercularis of the inferior frontal cortex, and supramarginal cortex. Cognition deficits were also significantly correlated with cortical thickness in these five regions in patients with schizophrenia. Cortical thickness of the right caudal middle frontal gyrus, superior frontal cortex and pars opercularis of the inferior frontal cortex also significantly mediated effects of cognitive deficits on TR.

CONCLUSION

Treatment resistance in schizophrenia was associated with reduced thickness in the right caudal middle frontal gyrus, superior frontal cortex, fusiform gyrus, pars opercularis of the inferior frontal cortex, and supramarginal cortex. Cortical abnormalities further mediate cognitive deficits known to be associated with TR.

Efficacy and safety of Lu AF35700 in treatment-resistant schizophrenia: A randomized, active-controlled trial with open-label extension

INTRODUCTION

Treatment resistance constitutes the highest burden of disease within schizophrenia. We hypothesized that the synergistic activity of Lu AF35700 at dopamine D1 and D2 receptors might provide superior antipsychotic effects versus first-line antipsychotic therapy in patients with treatment resistant schizophrenia (TRS), with a benign tolerability profile.

METHODS

This was a randomized, double-blind, active-controlled clinical trial (NCT02717195) followed by a one year open-label safety extension (NCT02892422). Following prospective confirmation of treatment resistance, patients were randomized (1:1:1) to 10 weeks double-blind treatment with Lu AF35700 10 mg or 20 mg, or active comparator (risperidone or olanzapine).

RESULTS

1628 patients were screened for TRS, of which 1092 entered the prospective confirmation period. Of these, 697 were randomized (Lu AF35700 10 mg n = 235, 20 mg n = 232, comparator n = 230) and 395 discontinued before randomization, including 264 (24 %) who responded to treatment. 586 patients completed the double-blind phase, of which 524 entered the open-label extension and 318 completed 1-year of open-label treatment. At the end of the double-blind phase, the mean ± SE change in positive and negative syndrome scale (PANSS) total score was -10.1 ± 0.96 for Lu AF35700 10 mg, -8.22 ± 0.98 for Lu AF35700 20 mg, and - 9.90 ± 0.97 for the comparator group. Treatment differences [95 % CI] versus comparator treatment were non-significant (-0.12 [-2.37; 2.13] and 1.67 [-0.59; 3.94], respectively). The most common adverse events with Lu AF35700 were increased weight and headache. Prolactin values decreased by ≥50 % in both sexes treated with Lu AF35700.

CONCLUSIONS

Despite evidence of antipsychotic efficacy, treatment with Lu AF35700 failed to differentiate from conventional antipsychotic treatment for patients with TRS.

Treatment-resistant schizophrenia: How far have we traveled?

Treatment-resistant schizophrenia is a lack of adequate response to antipsychotic medications resulting in incomplete functional and social recovery from the illness. Different definitions have been proposed for clinical practice and research work. Antipsychotics that are used in the management of schizophrenia mainly act on multiple dopaminergic pathways which are implicated in the development of symptoms of schizophrenia. Newer antipsychotics also are implicated to affect the serotonergic pathways. Clozapine is the only evidence-based treatment available for the management of treatment-resistant cases. Neurobiologically, there is a considerable overlap between treatment-resistant and treatment-responsive cases. The factors that are implicated in the evolution of treatment resistance are still not conclusive. These make the management of such patients a challenge. However, certain peculiarities of treatment-resistant schizophrenia have been identified which can guide us in the early identification and precise treatment of the treatment-resistant cases.

A systematic review of relational-based therapies for the treatment of auditory hallucinations in patients with psychotic disorders

BACKGROUND

Auditory hallucinations in patients with psychotic disorders may be very distressing. Unfortunately, a large proportion of individuals are resistant to pharmacological interventions and the gold-standard cognitive-behavioral therapy for psychosis offers at best modest effects. To improve therapeutic outcomes, several therapies have been created to establish a relationship between voice-hearers and their voices. With increasing literature, we conducted a systematic review of dialogical therapies and examined the evidence behind their efficacy.

METHODS

A systematic search was performed in PubMed, PsycINFO, Web of Science, and Google Scholar. Articles were included if they discussed the effects of dialogical interventions for patients with psychotic disorders.

RESULTS

A total of 17 studies were included within this systematic review. Cumulative evidence from various therapies has shown that entering in a dialog with voices is beneficial to patients, even those who are resistant to current pharmacological treatments. Heightened benefits have been mainly observed with Relating Therapy and Avatar Therapy/Virtual Reality assisted Therapy, with evidence generally of moderate quality. Both these interventions have shown large to very large effects on voices and voice-related distress as well as moderate to large magnitude improvements on affective symptoms. Though, cognitive-behavioral therapy for command hallucinations and making sense of voices noted no improvements on voices.

CONCLUSIONS

Literature on relational-based interventions with a strong emphasis on the relational aspects of voice hearing has shown positive effects. Results suggest that these dialogical therapies might surpass the efficacy of current gold-standard approaches.

Changes in corticostriatal connectivity and striatal tissue iron associated with efficacy of clozapine for treatment‑resistant schizophrenia

RATIONALE

Though numerous studies demonstrate the superiority of clozapine (CLZ) for treatment of persistent psychotic symptoms that are characteristic of treatment-refractory schizophrenia (TRS), what remains unknown are the neural and molecular mechanisms underlying CLZ's efficacy. Recent work implicates increased corticostriatal functional connectivity as a marker of response to non-CLZ, dopamine (DA) D2-receptor blocking antipsychotic drugs. However, it is undetermined whether this connectivity finding also relates to CLZ's unique efficacy, or if response to CLZ is associated with changes in striatal DA functioning.

OBJECTIVE

In a cohort of 22 individuals with TRS, we examined response to CLZ in relation to the following: (1) change in corticostriatal functional connectivity; and (2) change in a magnetic resonance-based measure of striatal tissue iron (R2'), which demonstrates utility as a proxy measure for elements of DA functioning.

METHODS

Participants underwent scanning while starting CLZ and after 12 weeks of CLZ treatment. We used both cortical and striatal regions of interest to examine changes in corticostriatal interactions and striatal R2' in relation to CLZ response (% reduction of psychotic symptoms).

RESULTS

We first found that response to CLZ was associated with an increase in corticostriatal connectivity between the dorsal caudate and regions of the frontoparietal network (P < 0.05, corrected). Secondly, we observed no significant changes in striatal R2' across CLZ treatment.

CONCLUSION

Overall, these results indicate that changes in corticostriatal networks without gross shifts in striatal DA functioning underlies CLZ response. Our results provide novel mechanistic insight into response to CLZ treatment.

Impact of clozapine on the expression of miR-675-3p in plasma exosomes derived from patients with schizophrenia

OBJECTIVES

Recently, the expression changes of microRNAs (miRNAs) in the serum exosomes (EXO) of schizophrenia (SCZ) have been reported. The aim of this study was to investigate the global expression changes of miRNA derived from the plasma EXO of patients with treatment-resistant schizophrenia (TRS) and the effects of clozapine on miRNA expression.

METHODS

Global miRNA expression changes in plasma EXO between TRS and controls were studied using microarray analysis. Then, miRNA expressions among TRS, non-TRS, and controls were confirmed with quantitative qPCR experiments. We also studied changes in EXO miRNA expression with in-vitro SH-SY5Y cells.

RESULTS

A microarray for miRNA expression analysis (nine controls vs. nine patients with TRS) revealed 13 up- and 18 downregulated miRNAs that were relevant to neuronal and brain development based on gene ontology analysis. Of those, upregulated miR-675-3p expression was successfully validated in the same cohort by qPCR experiments. Conversely, miR-675-3p expression levels were significantly decreased in the non-TRS cohort (50 controls vs. 50 patients without TRS without clozapine treatment).

CONCLUSIONS

We identified global miRNA changes in plasma EXO derived from patients with SCZ that were relevant to neuronal functions, among which, hsa-miR-675-3p expression was upregulated by clozapine treatment.

Efficacy and safety of maintenance electroconvulsive therapy (M-ECT) in treatment-resistant schizophrenia: A case series

BACKGROUND

Treatment-resistant schizophrenia (TRS) is a substantial burden to patients, caregivers, and the treating team. There is a lack of robust evidence to support the efficacy of various pharmacological and non-pharmacological measures to augment clozapine in this population. When used in conjunction with clozapine or other combination antipsychotic regimens, maintenance electroconvulsive therapy (M-ECT) can be a potential therapeutic option in preventing symptom exacerbation in TRS. However, there is limited evidence supporting the role of M-ECT in TRS.

AIM

To evaluate the efficacy and safety of maintenance electroconvulsive therapy in patients with TRS.

METHODOLOGY

Sociodemographic details, illness characteristics, details of M-ECT procedure, adverse events, and course of the illness were evaluated using a retrospective chart review at a tertiary care psychiatry centre in south India. Scores on Clinical Global Impression-Severity (CGI-S), Social and Occupational Functioning Assessment Scale (SOFAS), and Hindi Mental Status Examination were compared before and after the course of M-ECT.

RESULTS

Seven male and three female patients received M-ECT in the last eight years (range of 22-172 sessions). There was a reduction in hospitalizations for acute exacerbation and significant improvement in the patient's overall functioning without significant adverse effects.

CONCLUSION

Maintenance ECT can be a safe and effective treatment option for achieving symptom control in the long-term management of refractory schizophrenia. Controlled trials are needed in this area for further evidence.

Psychiatric Futility and Palliative Care for a Patient With Clozapine-resistant Schizophrenia

Recognizing futility is a challenging aspect of clinical medicine, particularly in psychiatry. We present a case of a man who suffered from clozapine-resistant schizophrenia. His illness was characterized by prominent religious delusions and severe self-starvation. Neither the intensity of his symptoms nor his quality of life improved with available psychiatric interventions, and he experienced significant iatrogenic harms from enforced treatments. Recognizing clinical futility, in collaboration with a diverse multidisciplinary team, and making a clear shift to a patient-centered palliative approach allowed the patient's treatment team to prioritize his autonomy and subjective meaning in his final months. Such approaches are understudied in psychiatry and warrant greater attention.

Neutropenia in Patients With Clozapine-Treated Schizophrenia: An Effect of Clozapine or a Consequence of SARS-CoV-2 Infection? A Systematic Review

BACKGROUND

Clozapine is the only approved antipsychotic for treatment-resistant schizophrenia. Despite its therapeutic benefits, it is still widely underused, mainly because of its potential to cause agranulocytosis and neutropenia. Prescribing clozapine in COVID-19-positive patients became more challenging because of this potential side effect. This article is a review of literature on the risk of neutropenia associated with clozapine treatment in patients with COVID-19.

AREAS OF UNCERTAINTY

In clozapine-treated COVID-19-positive patients, neutropenia was reported in some cases; is it a consequence of clozapine treatment or of SARS-Co2 infection?

DATA SOURCES

Data were extracted from 2 databases: PubMed/MEDLINE and Google Scholar. We selected all original reports, from March 2020 until May 2022, on neutropenia associated with clozapine treatment in positive COVID-19 patients. Eleven studies were selected for the final analysis.

THERAPEUTIC ADVANCES

Before the COVID-19 pandemic, neutropenia in clozapine-treated patients was reported in 3.8% of cases. During the pandemic, neutropenia rates seemed to be higher. As per the cause of neutropenia, studies reported contradictory results. We aim to clarify rates and causes of neutropenia in clozapine-treated COVID-19-positive patients.

RESULTS

Three hundred eighty-eight articles were initially selected from the 2 databases. After excluding duplicates, unrelated articles, reviews, and guidelines, 11 studies were analyzed, all centered on clozapine treatment, COVID-19 infection, and associated neutropenia.

CONCLUSIONS

Clozapine treatment in COVID-19-positive patients may be associated with a transient reduction of absolute neutrophils count, in some cases reaching neutropenia levels. Neutropenia rates reported in SARS-CoV-2-infected patients are higher than the prepandemic reports; therefore, we assume that the cause might be a result of the immunological interference between clozapine and SARS-CoV-2. Clozapine treatment needs to be continued whenever possible, with dose adjustments in relation to blood test results.

Comparison of Acute Followed by Maintenance ECT vs Clozapine on Psychopathology and Regional Cerebral Blood Flow in Treatment-Resistant Schizophrenia: A Randomized Controlled Trial

BACKGROUND AND HYPOTHESIS

In treatment-resistant schizophrenia (TRS), Clozapine is only approved treatment with undesirable side-effects, warranting better alternatives. Our hypothesis is acute followed by maintenance Electroconvulsive Therapy (M-ECT) will be comparable in efficacy and safety to Clozapine in TRS.

STUDY DESIGN

In this open-label trial, 60 TRS patients were randomized equally to M-ECT (following an acute-course) or Clozapine. Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Schizophrenia Scale (CGI-SCH), Montreal Cognitive Assessment (MoCA), and Global assessment of functioning (GAF) were measured and compared within and between the groups at baseline, 6 weeks, 12 weeks, and 24 weeks. SPECT-CT brain was done at baseline and 24 weeks to compare the changes in regional cerebral perfusion between the groups and correlate with the changes in the outcome-measures.

STUDY RESULTS

The PANSS-T scores changes from baseline over the observation-points were significant in both M-ECT and clozapine groups (P < .001), with comparatively better reduction with M-ECT (P < .001). Similar trends were observed in PANSS subscales, CGI-SCH and GAF in both groups, with significantly better improvement with M-ECT over the study-period. After 24 weeks, there was significantly better perfusion with M-ECT in bilateral prefrontal and temporal cortices (P < .05). With M-ECT, a positive correlation was found between changes in PANSS-P scores and left-lateral Temporal cortical perfusion (r = .465, P = .017).

CONCLUSIONS

Acute followed by M-ECT was more effective than clozapine over 6 months in reducing the positive and negative symptoms, general psychopathology, illness-severity, and improving the global functionality in TRS [clinicaltrials.gov: NCT03807882].

AMPA receptors in schizophrenia: A systematic review of postmortem studies on receptor subunit expression and binding

BACKGROUND

While altered expression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) type receptor has been reported in postmortem studies of schizophrenia, these findings are inconsistent. Therefore, we aimed to systematically review postmortem studies that investigated AMPA receptor expressions in schizophrenia.

METHODS

A systematic literature search was conducted for postmortem studies that measured AMPA receptor subunit expressions or receptor bindings in schizophrenia compared to healthy individuals on February 3, 2021, using Medline and Embase.

RESULTS

A total of 39 relevant articles were identified from 1360 initial reports. The dorsolateral prefrontal cortex (DLPFC) was the most investigated region (15 studies), followed by the medial temporal lobe (8 studies). For the DLPFC, 4/15 studies (26.7%) showed increased AMPA receptor binding or subunit expression in patients with schizophrenia compared to that in controls, especially in GRIA1 and GRIA4, 2/15 studies (13.3%) reported a decrease, particularly in GRIA2, and 8/15 studies (56.7%) found no significant differences. A decreased expression or receptor binding was observed in 6/8 studies (75.0%) in the subregions of the hippocampus in patients with schizophrenia compared to that in controls, whereas the other two studies found no significant differences.

CONCLUSION

Published data have reported decreased subunit expression or receptor binding in the hippocampus in schizophrenia. These findings were inconsistent in other brain regions, which might be due to the heterogeneity of this population, various study design, physiological changes after death, and limited number of studies. Future in vivo studies are warranted to examine AMPA receptor expressions in human brains, together with their comprehensive clinical characterization.

Trajectories of response in schizophrenia-spectrum disorders: A one-year prospective cohort study of antipsychotic effectiveness

BACKGROUND

Antipsychotic drugs remain the mainstay of schizophrenia treatment; however, their effectiveness has been questioned, and it is not possible to predict the response to a specific antipsychotic drug in an individual patient. Thus, it is important to compare the effectiveness of the various antipsychotics and search for possible response predictors.

AIM

To investigate the effectiveness of antipsychotic drugs, we examined response trajectories and predictors for belonging to different trajectory groups.

METHODS

The Bergen-Stavanger-Innsbruck-Trondheim (BeSt InTro) trial compared the effectiveness of three atypical antipsychotics-amisulpride, aripiprazole, and olanzapine-in a prospective, semirandomized, rater-blind, head-to-head design. Adult participants with a schizophrenia spectrum disorder diagnosis, according to international classification of diseases, Tenth Revision (ICD-10) F20–29, were included. Participants were followed for a period of 12 mo, with assessments at baseline; after one, three and six weeks; and after three, six, nine and 12 mo. A latent class mixed model was fitted to our data. The three-trajectory model based on the Positive and Negative Syndrome Scale (PANSS) total score reduction was found to have adequate fit, and the study drugs, as well as various demographic and clinical parameters, were tested as predictors for belonging to the different trajectory groups.

RESULTS

Overall, 144 participants were included, and 41% completed the 12-mo study period. The largest trajectory group, consisting of 74% of participants, showed a PANSS total score reduction of 59% from baseline to 12 mo (Good response group). A trajectory group comprising 13% of participants had their PANSS total score reduced by 82.5% at 12 mo (Strong response group), while the last response trajectory group comprising 13% of the participants had a PANSS total score reduction of 13.6% (Slight response group). The largest part of the total reduction for the Good and Strong response groups occurred at six weeks of treatment, amounting to 45% and 48% reductions from baseline, respectively. The use of amisulpride predicted belonging to the Strong response group, while unemployment, depression, and negative psychotic symptoms at baseline increased the chance of belonging to the Slight response group, indicating a poor response to antipsychotic drug treatment.

CONCLUSION

Most of the participants (87%) had a good outcome after one year. Amisulpride users, more often than aripiprazole and olanzapine users, belonged to the response trajectory group with a strong response.

Schizophrenia risk loci from xMHC region were associated with antipsychotic response in chronic schizophrenic patients with persistent positive symptom

We examined whether common variants from the extended major histocompatibility complex (xMHC) region contribute to the response to antipsychotic drugs (APDs) in patients with schizophrenia with persistent psychosis. Subjects participated in a prospective longitudinal study of the effect of APDs on psychopathology were temporally split into discovery (n = 88) and replication (n = 42) cohorts. The primary endpoint was a change in Brief Psychiatric Rating Scale at 6-week or 6-month after treatment. rs204991 (β = 3.917, p = 3.72 × 10^-6), the strongest signal associated with response at 6-week was located near C4A/C4B after a linear regression adjusted for covariates. xMHC SNP imputation disclosed much stronger signals (rs9268469, β = 5.140, p = 1.57 × 10^-7) and other weaker signals (p < 1 × 10^-5) spanning the entire xMHC region. All the variants were previously identified schizophrenia risk loci. Conditional fine-mapping revealed three subgroups of SNPs which were the eQTLs (p < 1 × 10^-7) for C4A, HLA-C, and BTN3A2 in disease-relevant tissue. Epistasis between HLA-C and C4A was observed (p = 0.019). Minor allele (G) carriers of rs204991, eQTL for C4A, having decreased risk for schizophrenia and lower imputed expression of C4A, had a better response to APDs. Some imputed HLA alleles associated with a decreased risk for schizophrenia had a positive association with improvement in psychotic symptoms. An independent cohort validated the association of change in psychosis with C4A. We provide evidence that genetic risk factors for schizophrenia from the xMHC region are associated with response to APDs and those variants significantly alter the imputed expression of C4A, HLA-C, and BTN3A2. The minor alleles predicting higher C4A level are associated with diminished improvement in psychotic symptoms after APD treatment.

Functional reconfiguration of cerebellum-cerebral neural loop in schizophrenia following electroconvulsive therapy

Recent evidence highlights the role of the cerebellum-cerebral loop in the pathophysiology of schizophrenia (SZ). Electroconvulsive therapy (ECT) is clinically applied to augment the effect of antipsychotic drugs. The study aims to address whether the cerebellum-cerebral loop is involved in the mechanisms of ECT's augmentation effect. Forty-two SZ patients and 23 healthy controls (HC) were recruited and scanned using resting-state functional MRI (rs-fMRI). Twenty-one patients received modified ECT plus antipsychotics (MSZ group), and 21 patients took antipsychotics only (DSZ group). All patients were re-scanned four weeks later. Brain functional network was constructed according to the graph theory. The sub-network exhibited longitudinal changes after ECT or medications were constructed. For the MSZ group, a sub-network involving default-mode network and cerebellum showed significant longitudinal changes. For the DSZ group, a different sub-network involving the thalamus, frontal and occipital cortex was found to be altered in the follow-up scan. In addition, the changing FC of the left cerebellar crus2 region was correlated with the changing scores of the psychotic symptoms only in the MSZ group but not in the DSZ group. In conclusion, the cerebral-cerebellum loop is possibly involved in the antipsychotic mechanisms of ECT for schizophrenia.