Search

We report a case of a 61‐year‐old female with 22q11.2 deletion syndrome (22q11.2DS) and a novel heterozygous nonsense variant in MAP1A, identified through whole‐genome sequencing (WGS). The patient presented with intellectual developmental disorder, treatment‐resistant schizophrenia (SCZ), and multiple congenital anomalies. Despite aggressive pharmacotherapy, she experienced persistent auditory hallucinations and negative symptoms. WGS revealed a 3 Mb deletion at 22q11.2 and a nonsense variant in MAP1A (c.4652T>G, p.Leu1551*). MAP1A, encoding microtubule‐associated protein 1A, is crucial for axon and dendrite development and has been implicated in autism spectrum disorder and SCZ. The MAP1A variant may contribute to the severe psychiatric phenotype, as it is thought to influence synaptic plasticity, a process also affected by 22q11.2 deletion. This case highlights the importance of WGS in identifying additional pathogenic variants that may explain phenotypic variability in 22q11.2DS. Thus, WGS can lead to a better understanding of the genetic architecture of 22q11.2DS. However, further studies are needed to elucidate the role of secondary genetic contributors in the diverse clinical presentations of 22q11.2DS. [ABSTRACT FROM AUTHOR]

Objective: The prevalence of treatment-resistant schizophrenia (TRS) among people with first-episode schizophrenia (FES) has been sub-optimally researched in Australia and internationally. We evaluated the prevalence of TRS among a cohort of FES patients and compared their sociodemographic and clinical characteristics to those with FES who were treatment responsive. Methods: Over 2 years, we collated demographic, clinical and treatment-related data of all patients with ICD-10 (International Classification of Diseases, Tenth revision) diagnosis of schizophrenia who were active in October 2020 at four early psychosis intervention services (EPIS) in Western Australia. We used a modified version of Suzuki et al. criteria to diagnose TRS. The data were analysed utilising descriptive statistics, the Mann–Whitney U test, Student's t -test and the False-Discovery Rate method. Results: The prevalence of TRS among the 167 patients diagnosed with FES was 41.3%, and the rates did not differ significantly between the services (p = 0.955). Those in the TRS group were less independent (p = 0.011), had more prolonged unemployment (p = 0.014) and were more likely to be on disability pension (p = 0.011) compared to the treatment responsive group. Furthermore, they had greater severity of symptoms (p = 0.002), longer duration of psychiatric symptoms (p = 0.019), more hospitalisations (p = 0.002) and longer cumulative admission durations (p = 0.002). Conclusions: Our study revealed that treatment resistance to antipsychotics is prevalent among people with FES managed at EPIS. Notably, it establishes an association between TRS and heightened clinical severity and psychosocial and treatment burden. These findings highlight the imperative for early detection of treatment resistance and timely and specialised interventions for this condition in mental health services. [ABSTRACT FROM AUTHOR]

Background: Although the number of studies on treatment-resistant schizophrenia (TRS) has been increasing, the global research hotspots and future research trends have not yet been established. Objective: This study identify the hotspots of TRS research and predict future research trends using a bibliometric analysis. Methods: The Web of Science Core Collection was searched using the keyword "TRS", econometric and co-occurrence analyses were conducted using CiteSpace and VOSviewer software, and the results were visualised. PRISMA reporting guidelines were used for this study. Results: In total, 912 publications were included in the analysis. The number of publications on TRS has shown an increasing trend over the past 20 years. The United States and University of London were the countries and institutions with the highest total number of publications, respectively. Schizophrenia Research was the journal with the highest number of articles. American Journal of Psychiatry was the most cited journal. Based on the results of this analysis, cognitive impairment, clozapine-resistant schizophrenia, early-onset schizophrenia, and early recognition of TRS will be hotspots for future research in this field. Conclusion: There has been an upward trend in the number of publications on TRS each year. However, issues such as how to use antipsychotics more efficiently to treat TRS and how to predict the emergence of TRS as early as possible are still in urgent need of research and are current challenges for clinicians. The results of this study not only predict and analyse future research hotspots but also help researchers identify appropriate research directions and partners. [ABSTRACT FROM AUTHOR]

Une proportion importante de personnes avec une schizophrénie résistante ne bénéficient pas d'un traitement par clozapine malgré son efficacité clairement démontrée dans cette indication. Les contraintes liées à la surveillance hématologique constituent un frein notoire à l'usage de clozapine, entraînant une vraie perte de chance pour les personnes concernées. Cet article d'opinion a pour objectif de questionner la pertinence du maintien des règles de surveillance hématologique actuellement en vigueur. Les études récentes sur l'évolution temporelle du risque d'agranulocytose imputable à la clozapine confirment que celui-ci devient négligeable au bout d'un un à deux ans de traitement. La surveillance hématologique entraîne des arrêts non justifiés de clozapine, car des épisodes neutropéniques transitoires pouvant être liés à d'autres causes sont fréquents en population générale. La surveillance hématologique mobilise du temps soignant et nécessite des adaptations organisationnelles parfois complexes dans les structures ambulatoires pour garantir la continuité des soins, notamment en cette période de sous-effectif médical et paramédical. La surveillance hématologique a déjà été allégée ou suspendue dans plusieurs pays après la période à risque d'agranulocytose. Le rapport bénéfice/risque du maintien de règles strictes de surveillance hématologiques de la clozapine paraît défavorable, suggérant que les temps pourraient donc être venus d'assouplir ces règles. A significant proportion of people with resistant schizophrenia do not receive treatment with clozapine, despite its clearly established efficacy in this indication. The constraints associated with haematological monitoring are a major obstacle to clozapine use, resulting in a real loss of opportunity for the people concerned. The aim of this opinion article is to question the relevance of maintaining the existing haematological monitoring rules for clozapine treatment. Recent studies on the temporal evolution of agranulocytosis risk attributable to clozapine confirm that this risk becomes negligible after one to two years of treatment. Stringent haematological monitoring leads to unjustified discontinuation of clozapine, as transient neutropenic episodes, which may be linked to other causes are common in the general population. Haematological monitoring requires nursing time and sometimes complex organisational adaptations in outpatient facilities to ensure continuity of care, particularly at a time when medical and paramedical staffing levels are low. Haematological monitoring has already been reduced or suspended in several countries after the period of risk of agranulocytosis. The benefit/risk ratio of maintaining strict haematological monitoring rules for clozapine appears unfavourable, suggesting that the time may have come to reduce the risk of agranulocytosis. [ABSTRACT FROM AUTHOR]

Introdution. Clozapine is a life-saving drug in treatmentresistant schizophrenia (TRS). Clozapine-induced sialorrhea (CIS) is a common adverse effect that frequently leads to reduced treatment adherence and additional complications, thus affecting its efficacy in treatment-resistant schizophrenia. Objective. The aim of this article was to report two cases of CIS in two TRS patients who were treated using an extemporaneously compounded trospium oromucosal suspension. Methodology. The severity and frequency of CIS were evaluated using two different scales, the Toronto Nocturnal Hypersalivation Rating Scale (TNHR) and the Drooling Severity and Frequency Scale (DSF), before and during trospium treatment. Conclusions. We considered this trospium-based extemporaneously compounded oromucosal formulation as a promising solution for CIS and for maintaining clozapine adherence in patients with treatment-resistant schizophrenia. [ABSTRACT FROM AUTHOR]

Concern about clozapine-associated neutropenia contributes to clozapine's underutilization and racial disparities in access. People with African ancestry are more likely to have lower normative absolute neutrophil counts (ANC), associated with the Duffy null genetic polymorphism. Recent data on clozapine-associated neutropenia in the US are lacking. Patients prescribed clozapine in the Johns Hopkins Medicine electronic medical record (EMR) between 2013 and 2023 were identified. Duffy null Associated Neutrophil Count (DANC) was assigned if there were two ANC's < 2000 cells/μL, >30 days apart, before starting clozapine. Rates of neutropenia, timing of first neutropenia, and demographic differences were explored. 974 received clozapine and had ANC's available, with 63.9 % male, 51.1 % White, and 39 % Black. 287 were presumed to start clozapine during the study period, and were 62.4 % male, 46 % White, and 44.9 % Black. No patients developed severe neutropenia. 59 (6.1 %) developed mild or moderate neutropenia. 19 (6.6 %) new starts had presumed DANC, and none developed neutropenia. 11 of 16 presumed new starts who developed neutropenia did so within eight months. No demographic differences were found between groups for presumed new starts. For non-new starts, where DANC assignment was not possible, Black patients were more likely than White patients to develop neutropenia (OR 3.48, 95 % CI [1.65, 7.73]). To our knowledge, this is the first observational study of clozapine-associated neutropenia in the US in the past decade, and it includes a substantial proportion of Black patients. ANC monitoring requirements may be too strict, contributing to clozapine underutilization. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: The impact of obtaining second-opinion consultations on diagnoses of schizophrenia spectrum disorders was evaluated. Methods: A retrospective chart review was conducted for 177 patients referred to a psychosis consultation service at an academic medical center from January 1, 2017, to October 1, 2023; these consultations aimed to clarify a diagnosis of psychosis. Diagnoses made before and after consultations were compared, and treatment recommendations resulting from the consultation visit were summarized. Results: Among patients without a preconsultation diagnosis of schizophrenia, 28% (N=28 of 100) received a postconsultation diagnosis of schizophrenia. Among 62 patients with a postconsultation diagnosis of treatment-resistant schizophrenia (TRS), 56% (N=35) received this diagnosis only after consultation. Nearly all of these patients were advised to begin taking clozapine, and electroconvulsive therapy was less commonly recommended. Conclusions: Expert consultation facilitates timely identification and optimal treatment of schizophrenia and its more severe subtype, TRS. [ABSTRACT FROM AUTHOR]

Abstract We report a case of a 61‐year‐old female with 22q11.2 deletion syndrome (22q11.2DS) and a novel heterozygous nonsense variant in MAP1A, identified through whole‐genome sequencing (WGS). The patient presented with intellectual developmental disorder, treatment‐resistant schizophrenia (SCZ), and multiple congenital anomalies. Despite aggressive pharmacotherapy, she experienced persistent auditory hallucinations and negative symptoms. WGS revealed a 3 Mb deletion at 22q11.2 and a nonsense variant in MAP1A (c.4652T>G, p.Leu1551*). MAP1A, encoding microtubule‐associated protein 1A, is crucial for axon and dendrite development and has been implicated in autism spectrum disorder and SCZ. The MAP1A variant may contribute to the severe psychiatric phenotype, as it is thought to influence synaptic plasticity, a process also affected by 22q11.2 deletion. This case highlights the importance of WGS in identifying additional pathogenic variants that may explain phenotypic variability in 22q11.2DS. Thus, WGS can lead to a better understanding of the genetic architecture of 22q11.2DS. However, further studies are needed to elucidate the role of secondary genetic contributors in the diverse clinical presentations of 22q11.2DS.

AIM: The aim of the study was to study the efficacy of modified electroconvulsive therapy (MECT) as an augmentation agent in schizophrenia, with particular emphasis in treatment-resistant schizophrenia. MATERIAL AND METHODS: A prospective open-label, raters blinded within a group interventional study done over 1 year with 40 consenting adults with a diagnosis of treatment-resistant schizophrenia as per Conley and Kelly’s criteria. With preanesthetic clearance, they were put on a supervised regular MECT regimen after baseline clinical global impression (CGI), PANSS, and Brief Psychiatric Rating Scale (BPRS) application with improvement recorded by repeat application of psychopathology measurement scales. RESULTS: after a mean of 11.10 ± 1.6 MECT sessions ranging from 8 to 14, we observed an improvement of 30.6% ± 3.5% in total PANSS score with significant improvement in CGI and BPRS. CONCLUSION: The study endorses the efficacy of MECT augmentation in treatment-resistant schizophrenia.

Introduction: Predictors of functioning are well-studied in schizophrenia, but much less so in treatment-resistant schizophrenia (TRS). In this study, we aim to investigate contributions of schizophrenia symptom domains and neurocognition to predict functioning in a TRS population (n = 146). Methods: Participants were assessed on the Positive and Negative Syndrome Scale (PANSS), to calculate scores for five symptomfactors (Positive, Negative, Cognitive, Depressive and Hostility) and two negative symptom constructs (Diminished Expressivity (DE), and Social Anhedonia (SA) as part of the Motivation and Pleasure-related dimension), based on a previously validated model, modified in accordance with EPA guidelines on negative symptoms assessment. Neurocognition was assessed with symbol coding and digit sequencing tasks from the Brief Assessment of Cognition in Schizophrenia (BACS). Functioning was assessed with the Social and Occupational Functioning Assessment Scale (SOFAS), employment status andWorld Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). Multiple regression analyses were performed on psychopathology scores and BACS scores against all three measures of functioning, controlling for age and sex. For WHODAS, regression with PANSS scores of significant symptom factors were also performed. Results: A lower severity of negative symptoms in the SA dimension was the strongest predictor of higher functioning across all three functioning measures. Neurocognition, in particular processing speed and attention assessed on the symbol coding task, predicted employment. A lower severity of somatic concerns and depressive symptoms was associated with lesser self-reported disability on WHODAS. Discussion: This study represents a first attempt at elucidating significant predictors of functioning in TRS. We highlight negative symptoms and neurocognition as important treatment targets to improve functioning in TRS, consistent with previous studies in general schizophrenia. [ABSTRACT FROM AUTHOR]

Recent operational criteria for treatment-resistant schizophrenia (TRS) recognized positive and negative symptoms. TRS patients may have heterogeneity in negative symptoms, but empirical data were lacking. We aimed to characterize TRS patients based on negative symptoms using cluster analysis, and to examine between-cluster differences in social functioning. We administered the Clinical Assessment Interview of Negative symptoms (CAINS), Brief Negative Symptom Scale (BNSS), the Positive and Negative Syndrome Scale (PANSS) and the Social and Occupational Functional Assessment (SOFAS to 126 TRS outpatients. All patients also completed the Temporal Experience of Pleasure Scale (TEPS), the Emotion Expressivity Scale (EES), and the Social Functional Scale (SFS). A two-stage hierarchical cluster analysis was performed with the CAINS, TEPS and EES as clustering variables. We validated the clusters using ANOVAs to compare group differences in the BNSS, PANSS, SOFAS and SFS. Clustering indices supported a 3-cluster solution. Clusters 1 (n = 46) and 3 (n = 16) exhibited higher CAINS scores than Cluster 2 (n = 64), and were negative-symptom TRS subtypes. Cluster 1 reported lower TEPS than Cluster 3; but Cluster 3 reported lower EES than Cluster 1. Upon validation, Clusters 1 and 3 exhibited higher BNSS scores than Cluster 2, but only Cluster 1 exhibited lower SOFAS and higher PANSS general symptoms than Cluster 2. Both Clusters 1 and 3 had higher self-report functioning than Cluster 2. We provided evidence for heterogeneity of negative symptoms in TRS. Negative symptoms can characterize TRS patients and predict functional outcome. • This empirical study characterized TRS patients using the CAINS, self-rated experiential pleasure and emotion expressivity. • Hierarchical cluster analysis categorized 126 TRS patients into three clusters. • The cluster with the highest CAINS-negative symptoms and lowest experiential pleasure exhibited poor social functioning. • Our findings encouraged operational criteria for TRS to incorporate BNSS and CAINS-measured negative symptoms. [ABSTRACT FROM AUTHOR]

Objective: Previous research has suggested that demographic factors affect the likelihood of a patient with schizophrenia receiving a clozapine prescription. The authors aimed to determine the impact of race, social determinants of health, gender, rurality, and care patterns on clozapine prescription rates. Methods: This cross-sectional observational study used structured electronic health records data from 3,160 adult patients diagnosed as having schizophrenia between October 1, 2015, and November 30, 2021, in a multifacility health system. The social vulnerability index (SVI) was used to quantify social determinants of health. Descriptive data analysis, logistic regression, and sensitivity analysis were conducted to identify differences between patients with schizophrenia who received a clozapine prescription and those who received antipsychotic medications other than clozapine. Results: Overall, 401 patients with schizophrenia were given a clozapine prescription during the study period, and 2,456 received antipsychotics other than clozapine. Results of the logistic regression indicated that White race (OR=1.71, compared with Black race), community minority status and language SVI score (OR=2.97), and increased treatment duration (OR=1.36) were significantly associated with a higher likelihood of clozapine prescription; gender, rurality, age at first diagnosis, and ethnicity did not influence the likelihood of receiving clozapine. Conclusions: Black patients with schizophrenia had a lower likelihood of receiving a clozapine prescription compared with White patients, even after analyses accounted for demographic variables, social determinants of health, and care access patterns. Given the effectiveness of clozapine in managing treatment-resistant schizophrenia, it is crucial for future research to better understand the factors contributing to this treatment disparity. [ABSTRACT FROM AUTHOR]

Clozapine is the only approved antipsychotic for treatment-resistant schizophrenia (TRS). Although a large body of evidence supports its efficacy and favorable risk-benefit ratio in individuals who have failed two or more antipsychotics, clozapine remains underused. However, variations in clozapine utilization across geographic and clinical settings suggest that it could be possible to improve its use. In this narrative review and expert opinion, we summarized information available in the literature on the mechanisms of action, effectiveness, and potential adverse events of clozapine. We identified barriers leading to discouragement in clozapine prescription internationally, and we proposed practical solutions to overcome each barrier. One of the main obstacles identified to the use of clozapine is the lack of appropriate training for physicians: we highlighted the need to develop specific professional programs to train clinicians, both practicing and in residency, on the relevance and efficacy of clozapine in TRS treatment, initiation, maintenance, and management of potential adverse events. This approach would facilitate physicians to identify eligible patients and offer clozapine as a treatment option in the early stage of the disease. We also noted that increasing awareness of the benefits of clozapine among healthcare professionals, people with TRS, and their caregivers can help promote the use of clozapine. Educational material, such as leaflets or videos, could be developed and distributed to achieve this goal. The information provided in this article may be useful to improve disease burden and support healthcare professionals, patients, and caregivers navigating the complex pathways to TRS management. [ABSTRACT FROM AUTHOR]

Background Clozapine is the recommended treatment for managing treatment-resistant schizophrenia (TRS), and immunological mechanisms may be involved in its unique antipsychotic efficacy. This study investigated whether baseline immune abnormalities measured with blood cell count ratios can predict the clinical response after initiating treatment with clozapine in patients with clozapine naïve TRS. Methods A longitudinal design was developed, involving 32 patients diagnosed with treatment-resistant, clozapine-naïve schizophrenia-spectrum disorder. Patients were evaluated at baseline before clozapine starting and 8 weeks of follow-up. Psychopathological status and immune abnormalities (blood cell count ratios: neutrophil-lymphocyte ratio [NLR], monocyte-lymphocyte ratio [MLR], platelet-lymphocyte ratio [PLR] and basophil-lymphocyte ratio [BLR]) were evaluated in each visit. Results Baseline NLR (b=− 0.364; p=0.041) and MLR (b =− 0.400; p=0.023) predicted the change in positive symptoms over the 8-week period. Patients who exhibited a clinical response showed higher baseline NLR (2.38±0.96 vs. 1.75±0.83; p=0.040) and MLR (0.21±0.06 vs. 0.17±0.02; p=0.044) compared to non-responders. In the ROC analysis, the threshold points to distinguish between responders and non-responders were approximately 1.62 for NLR and 0.144 for MLR, yielding AUC values of 0.714 and 0.712, respectively. No statistically significant differences were observed in the blood cell count ratios from baseline to the 8-week follow-up. Conclusion Our study emphasizes the potential clinical significance of baseline NLR and MLR levels as predictors of initial clozapine treatment response in patients with TRS. Future studies with larger sample sizes and longer follow-up periods should replicate our findings. [ABSTRACT FROM AUTHOR]

BackgroundAlthough the number of studies on treatment-resistant schizophrenia (TRS) has been increasing, the global research hotspots and future research trends have not yet been established.ObjectiveThis study identify the hotspots of TRS research and predict future research trends using a bibliometric analysis.MethodsThe Web of Science Core Collection was searched using the keyword “TRS”, econometric and co-occurrence analyses were conducted using CiteSpace and VOSviewer software, and the results were visualised. PRISMA reporting guidelines were used for this study.ResultsIn total, 912 publications were included in the analysis. The number of publications on TRS has shown an increasing trend over the past 20 years. The United States and University of London were the countries and institutions with the highest total number of publications, respectively. Schizophrenia Research was the journal with the highest number of articles. American Journal of Psychiatry was the most cited journal. Based on the results of this analysis, cognitive impairment, clozapine-resistant schizophrenia, early-onset schizophrenia, and early recognition of TRS will be hotspots for future research in this field.ConclusionThere has been an upward trend in the number of publications on TRS each year. However, issues such as how to use antipsychotics more efficiently to treat TRS and how to predict the emergence of TRS as early as possible are still in urgent need of research and are current challenges for clinicians. The results of this study not only predict and analyse future research hotspots but also help researchers identify appropriate research directions and partners.

Abstract Background Glutamatergic function abnormalities have been implicated in the etiology of treatment-resistant schizophrenia (TRS), and the efficacy of clozapine may be attributed to its impact on the glutamate system. Recently, evidence has emerged suggesting the involvement of immune processes and increased prevalence of antineuronal antibodies in TRS. This current study aimed to investigate the levels of multiple anti-glutamate receptor antibodies in TRS and explore the effects of clozapine on these antibody levels. Methods Enzyme linked immunosorbent assay (ELISA) was used to measure and compare the levels of anti-glutamate receptor antibodies (NMDAR, AMPAR, mGlur3, mGluR5) in clozapine-treated TRS patients (TRS-C, n = 37), clozapine-naïve TRS patients (TRS-NC, n = 39), and non-TRS patients (nTRS, n = 35). Clinical symptom severity was assessed using the Positive and Negative Symptom Scale (PANSS), while cognitive function was evaluated using the MATRICS Consensus Cognitive Battery (MCCB). Result The levels of all four glutamate receptor antibodies in TRS-NC were significantly higher than those in nTRS (p

Objective: Markers for treatment resistance in schizophrenia are needed to reduce delays in effective treatment. Nigrostriatal hyperdopaminergic function plays a critical role in the pathology of schizophrenia, yet antipsychotic nonresponders do not show increased dopamine function. Neuromelanin-sensitive MRI (NM-MRI), which indirectly measures dopamine function in the substantia nigra, has potential as a noninvasive marker for nonresponders. Increased NM-MRI signal has been shown in psychosis, but has not yet been assessed in nonresponders. In this study, the authors investigated whether nonresponders show lower NM-MRI signal than responders. Methods: NM-MRI scans were acquired in 79 patients with first-episode psychosis and 20 matched healthy control subjects. Treatment response was assessed at a 6-month follow-up. An a priori voxel-wise analysis within the substantia nigra tested the relation between NM-MRI signal and treatment response in patients. Results: Fifteen patients were classified as nonresponders and 47 patients as responders. Seventeen patients were excluded, primarily because of medication nonadherence or change in diagnosis. Voxel-wise analysis revealed 297 significant voxels in the ventral tier of the substantia nigra that were negatively associated with treatment response. Nonresponders and healthy control subjects had significantly lower NM-MRI signal than responders. Receiver operating characteristic curve analysis showed that NM-MRI signal separated nonresponders with areas under the curve between 0.62 and 0.85. In addition, NM-MRI signal in patients did not change over 6 months. Conclusions: These findings provide further evidence for dopaminergic differences between medication responders and nonresponders and support the potential of NM-MRI as a clinically applicable marker for treatment resistance in schizophrenia. [ABSTRACT FROM AUTHOR]

As access to an essential part of clozapine research from the former Union of Soviet Socialist Republics (USSR) states is very limited, quality aspects have not gained attention so far, and harmonization with modern research standards remains unclear. We performed a systematic search in PubMed, Embase and scientific indexes from former USSR states for articles published in Russian language till January 2023 (PROSPERO Reg. Number CRD42023386737) and assessed their quality using the modified Strengthening the reporting of observational studies in epidemiology (STROBE)-Checklist. We compared quality aspects for papers published before and after 2000. A total of 60 papers were considered. Conflicts of interests and funding sources were reported in 5 and 3 (8 % and 5 %) studies respectively; ethical approval was warranted in two studies (3 %). Statistical analysis was performed in 57 (95 %) studies, but statistical methods were described in 21 (35 %) studies. When comparing studies before and after 2000, there was a trend towards improvement for several aspects, with the only significant differences being the objectives' specification (43 vs 83 %, p < 0.003) and the reporting of statistical methodology (0.0 vs 46 %, p < 0.001), which were more frequently available in papers after 2000. Clozapine papers in Russian language suffered from severe methodological drawbacks limiting generalizability. Changes regarding standardization, transparency, ethics, and good scientific practice are urgently required. Using reporting checklists and predefining protocols are the first steps towards quality upgrade and accelerate the integration of science from the former USSR states into the world scientific system. [Display omitted] [ABSTRACT FROM AUTHOR]

Clozapine is recognized as the gold standard medication for treatment-resistant schizophrenia. Despite the general recommendation of administering in a divided dosing regimen, clozapine is often prescribed once daily at night in clinical practice. This study aims to compare patient characteristics, psychiatric symptoms, side effects, and plasma concentration of clozapine between once-daily dosing and divided dosing regimens. This cross-sectional study included 159 participants with treatment-resistant schizophrenia or schizoaffective disorder. Participant's demographic information, anthropometric data, and medical history were collected. Their psychiatric symptoms, cognition, functioning, and side effects were evaluated. Once-daily dosing regimen was associated with younger age and competitive employment. Lower clinical symptom severity, better functioning and cognitive performance were observed in the once-daily dosing group. Lower daily dose of clozapine, trough plasma concentrations of clozapine and norclozapine were also significantly associated with once-daily dosing regimen. The study results support once-daily dosing of clozapine as a viable option to selected patients in clinical practice, as no association of severe symptoms or side effects were associated with once-daily dosing regimen. More studies are needed to examine the relationship between clinical outcomes and clozapine dosing regimen. [ABSTRACT FROM AUTHOR]

This study investigates whether early clozapine use is associated with improved responses in different clinical domains, including positive and negative symptoms, functioning, and well-being. Data from 254 clozapine-treated patients at Cambridgeshire and Peterborough NHS Foundation Trust (CPFT) were analysed. Among them, 231 (90.9 %) had a diagnosis of schizophrenia, 21 (8.3 %) schizoaffective disorder, and 2 (0.8 %) had other diagnoses. The International Classification of Diseases-Mortality and Morbidity Statistics criteria (ICD-10) were employed (World Health Organization, 1992). The cohort was assessed using the positive and negative syndrome scale (PANSS), the Brief Negative Symptom Scale (BNSS), Global Assessment of Functioning Scale (GAF), and the short version of Warwick-Edinburgh Mental Well-being Scale (SWEMWBS). Logistic regression models (for positive and negative symptom remission) and linear regression (for functioning and well-being) were utilized to assess the influence of time to clozapine initiation (TCI), age at the first episode of psychosis (AFE), duration of clozapine treatment (DCT), and gender. Early clozapine treatment (within the first three years after the first episode of psychosis) was associated with increased negative symptom remission (exp (B) = 0.38; p = 0.02) and higher functioning scores (β = −0.12, p = 0.046). However, no effect of time to clozapine initiation was found on positive symptom remission rates or well-being scores. Initiating clozapine treatment within the first 3 years of the first episode of psychosis may lead to reduced severity of negative symptoms and improved functioning in clozapine-treated patients. The time to clozapine initiation did not influence its effect on positive symptom remission rates. [ABSTRACT FROM AUTHOR]

Access to literature on clozapine in Russian language remains strikingly limited. We aimed to identify and translate clinical evidence on clozapine-based treatment outcomes. We performed a systematic review in PubMed, Embase and scientific indexes from former USSR states searching for articles published in Russian from the database inception till January 2023 and summarized the data in a scoping review (PROSPERO Reg. Number CRD42023386737). A total of 60 papers were included comprising eight main topic categories: 1) clozapine-related intoxications (n = 20), 2) effectiveness/efficacy and safety of clozapine treatment (n = 14), 3) adverse drug-induced reactions (ADRs) related to clozapine treatment (n = 9), 4) therapeutic drug monitoring for clozapine (n = 5), 5) combination of clozapine and non-pharmacological treatments (n = 4), 6) pharmacoepidemiology of clozapine (n = 3), 7) effects of clozapine on the brain electrical activity (n = 3), and 8) novel clozapine formulations (n = 2). Among clozapine-related intoxications there were reports of criminal poisoning, which was associated with low lethality. Worse outcomes were accompanied by systemic reactions to intoxications. Clinical benefits of hemoadsorption were reported in the management of clozapine-related intoxications. Only half of studies reporting clozapine effectiveness used standardized scales to assess outcomes. Clozapine superiority in treatment-resistant schizophrenia (TRS) was replicated in one trial. No reports of clozapine-related agranulocytosis were identified. Clozapine ranked among most prescribed antipsychotics for TRS and non-TRS. As clinical research in former USSR states is advancing to adopt western clinical research standards, comparability and extrapolation of findings is expected to increase, with transfer of older findings to clinical practice being particularly challenging. [ABSTRACT FROM AUTHOR]

Objective: To determine the delay in Clozapine initiation in patients with treatment-resistance schizophrenia who presented to the Tertiary psychiatric facilities. Study Design: Cross-sectional study. Place and Duration of Study: Department of Psychiatry Combined Military Hospital, Peshawar and Department of Psychiatry Combined Military Hospital, Nowshera Pakistan, from Jan to Dec 2023. Methodology: We recruited 103 treatment-resistant schizophrenia and Clozapine naïve patients after obtaining their consent. Patients were included by reviewing their medical history and records. The diagnosis was made by clinical interview and use of Positive and Negative syndrome scale. The data were recorded using a semi-structured questionnaire. Results: Out of 103 patients, 78(75.7%) were male and 25(24.3%) were female. Regarding the initiation of Clozapine treatment, the mean duration from diagnosis to treatment initiation was 6.23±4.82 years. Patients were categorised based on the time to Clozapine initiation into early initiators (=4 years), intermediate initiators (>4 years to <15 years), and delayed initiators (>15 years). The distribution across these categories was 51(49.5%) for early initiators, 47(45.6%) for intermediate initiators, and 5(4.9%) for delayed initiators. Conclusion: There is a significant delay in Clozapine initiation despite adequate evidence to initiate it early. Clinicians should start Clozapine whenever there is a need. [ABSTRACT FROM AUTHOR]

Background: Clozapine is the most effective antipsychotic with respect to the incidence of discontinuation and is indicated for treatment-resistant schizophrenia. Although the recommendation for clozapine administration is divided dosing, once-daily dosing of clozapine is commonly prescribed in many countries. However, there is currently no clinical data comparing all-cause discontinuation between the 2 methods of administration of clozapine. Objectives: To compare the all-cause discontinuation and safety of clozapine administration between once-daily and divided dosing regimens. Methods: This was a retrospective cohort study. Participants were patients with treatment-resistant schizophrenia who had received 300 to 600 mg/day of clozapine for at least 3 months. Data were collected from outpatient medical records at Somdet Chaopraya Institute of Psychiatry. Eligible patients were classified into 2 groups: once-daily dosing and divided dosing. The primary outcome was the all-cause discontinuation rate between groups. The duration of the study was 2 years. Results: One hundred eighteen patients were included and analyzed in this study (once-daily dosing group: n = 58; divided dosing group: n = 60). There was no significant difference in all-cause discontinuation between the 2 groups (odds ratio 1.03; 95% confidence interval: [0.28, 3.79]: P = 1.00), or adverse events between groups. Conclusion and Relevance: In patients with treatment-resistant schizophrenia, there were no significant differences in effectiveness or safety between once-daily and divided dosing of clozapine. Further prospective studies with larger sample sizes are required to confirm these findings. [ABSTRACT FROM AUTHOR]

Treatment-resistant schizophrenia (TRS) is a challenging condition to treat for the correctional psychiatrist. Guidelines from the American Psychiatric Association indicate that the first-line pharmacotherapy for TRS is the use of the atypical antipsychotic clozapine. The use of clozapine is unique in that it requires patient adherence with weekly blood draws as a prophylactic measure against agranulocytosis and leukopenia. In the correctional setting, patients with severe and persistent schizophrenia are frequently nonadherent due to lack of insight and anemic access to health care resources, specifically as these pertain to clozapine. Therefore, an alternative treatment option would be a welcome solution for this demographic. Our literature review demonstrates a limited number of studies documenting the successful use of clozapine alternatives or combination antipsychotic therapy for treatment of TRS. In this article, we present a putative case where we believe that a combination regimen of paliperidone palmitate, oral aripiprazole, and escitalopram led to a notable mitigation of both positive and negative symptoms of psychosis in the case of an incarcerated patient with TRS, as well as an improvement in functional stability, which was conducive to housing in a less restrictive setting. A brief review of the published literature follows the report. [ABSTRACT FROM AUTHOR]

Background: A significant proportion of people with clozapine-treated schizophrenia develop 'checking' compulsions, a phenomenon yet to be understood. Aims: To use habit formation models developed in cognitive neuroscience to investigate the dynamic interplay between psychosis, clozapine dose and obsessive–compulsive symptoms (OCS). Method: Using the anonymised electronic records of a cohort of clozapine-treated patients, including longitudinal assessments of OCS and psychosis, we performed longitudinal multi-level mediation and multi-level moderation analyses to explore associations of psychosis with obsessiveness and excessive checking. Classic bivariate correlation tests were used to assess clozapine load and checking compulsions. The influence of specific genetic variants was tested in a subsample. Results: A total of 196 clozapine-treated individuals and 459 face-to-face assessments were included. We found significant OCS to be common (37.9%), with checking being the most prevalent symptom. In mediation models, psychosis severity mediated checking behaviour indirectly by inducing obsessions (r = 0.07, 95% CI 0.04–0.09; P < 0.001). No direct effect of psychosis on checking was identified (r = −0.28, 95% CI −0.09 to 0.03; P = 0.340). After psychosis remission (n = 65), checking compulsions correlated with both clozapine plasma levels (r = 0.35; P = 0.004) and dose (r = 0.38; P = 0.002). None of the glutamatergic and serotonergic genetic variants were found to moderate the effect of psychosis on obsession and compulsion (SLC6A4, SLC1A1 and HTR2C) survived the multiple comparisons correction. Conclusions: We elucidated different phases of the complex interplay of psychosis and compulsions, which may inform clinicians' therapeutic decisions. [ABSTRACT FROM AUTHOR]

Background: Glutamatergic function abnormalities have been implicated in the etiology of treatment-resistant schizophrenia (TRS), and the efficacy of clozapine may be attributed to its impact on the glutamate system. Recently, evidence has emerged suggesting the involvement of immune processes and increased prevalence of antineuronal antibodies in TRS. This current study aimed to investigate the levels of multiple anti-glutamate receptor antibodies in TRS and explore the effects of clozapine on these antibody levels. Methods: Enzyme linked immunosorbent assay (ELISA) was used to measure and compare the levels of anti-glutamate receptor antibodies (NMDAR, AMPAR, mGlur3, mGluR5) in clozapine-treated TRS patients (TRS-C, n = 37), clozapine-naïve TRS patients (TRS-NC, n = 39), and non-TRS patients (nTRS, n = 35). Clinical symptom severity was assessed using the Positive and Negative Symptom Scale (PANSS), while cognitive function was evaluated using the MATRICS Consensus Cognitive Battery (MCCB). Result: The levels of all four glutamate receptor antibodies in TRS-NC were significantly higher than those in nTRS (p < 0.001) and in TRS-C (p < 0.001), and the antibody levels in TRS-C were comparable to those in nTRS. However, no significant associations were observed between antibody levels and symptom severity or cognitive function across all three groups after FDR correction. Conclusion: Our findings suggest that TRS may related to increased anti-glutamate receptor antibody levels and provide further evidence that glutamatergic dysfunction and immune processes may contribute to the pathogenesis of TRS. The impact of clozapine on anti-glutamate receptor antibody levels may be a pharmacological mechanism underlying its therapeutic effects. [ABSTRACT FROM AUTHOR]

Background Although clozapine is the most effective antipsychotic for people with treatment-resistant schizophrenia (TRS), only 40% of people with TRS respond, and there is limited evidence for augmentation agents. Cannabidiol (CBD) reduces positive symptoms in individuals with schizophrenia, but no trials have specifically examined its efficacy in those with clozapine-resistant schizophrenia. Aims To examine the clinical efficacy of CBD augmentation in people with clozapine-resistant schizophrenia. Method This is a 12-week randomised, placebo-controlled, double-blind, parallel-group trial (registration number: ACTRN12622001112752). We will recruit 88 individuals with clozapine-resistant schizophrenia, randomised (1:1) to 1000 mg daily CBD versus placebo. Eligible individuals will be aged between 18 and 64 years, fulfil DSM-IV criteria for schizophrenia or schizoaffective disorder, have a total PANSS (Positive and Negative Syndrome Scale) score ≥60, have received oral clozapine for at least 18 weeks and have a clozapine level of >350 ng/mL. Interim analyses will be conducted at 25, 50 and 75% recruitment; these will also provide an opportunity to reallocate participants dependent on conditional power. The primary endpoint will be the difference in PANSS positive scores at the end of week 12. Secondary endpoints include depression, anxiety, sleep, quality of life, alcohol consumption, change in weight and metabolic syndrome components, and neurocognitive measures, as well as safety and tolerability. Discussion Novel treatments for clozapine-resistant schizophrenia are urgently needed. If found to be effective, CBD may have a role as a novel and safe adjunct to clozapine.

Abstract Background Inflammation has an important role in the pathogenesis of schizophrenia. The aim of this study was to investigate the levels of tumor necrosis factor (TNF) and matrix metalloproteinase-2 (MMP-2) in male patients with treatment-resistant schizophrenia (TRS) and chronic medicated schizophrenia (CMS), and the relationship with psychopathology. Methods The study enrolled 31 TRS and 49 cm male patients, and 53 healthy controls. Serum MMP-2 and TNF-α levels were measured by the Luminex liquid suspension chip detection method. Positive and Negative Syndrome Scale (PANSS) scores were used to evaluate symptom severity and Repeatable Battery for the Assessment of Neuropsychological Status was used to assess cognitive function. Results Serum TNF-α and MMP-2 levels differed significantly between TRS, CMS and healthy control patients (F = 4.289, P = 0.016; F = 4.682, P = 0.011, respectively). Bonferroni correction demonstrated that serum TNF-α levels were significantly elevated in CMS patients (P = 0.022) and MMP-2 levels were significantly higher in TRS patients (P = 0.014) compared to healthy controls. In TRS patients, TNF-α was negatively correlated with age (r=-0.435, P = 0.015) and age of onset (r=-0.409, P = 0.022). In CMS patients, MMP-2 and TNF-α were negatively correlated with PANSS negative and total scores, and TNF-α was negatively correlated with PANSS general psychopathology scores (all P 0.05). Conclusion The results indicate the involvement of inflammation in the etiology of TRS and CMS. Further studies are warranted.

Background: Clozapine is the primary antipsychotic (APD) for treatment-resistant schizophrenia (TRS). However, only 40% of patients with TRS respond to clozapine, constituting a subgroup of clozapine-resistant patients. Recently, the neuropeptide orexin-A was shown to be involved in the pathophysiology of schizophrenia. This study evaluated the association of orexin-A levels with the clozapine response in patients with TRS. Methods: We recruited 199 patients with schizophrenia, including 37 APD-free and 162 clozapine-treated patients. Clozapine-treated patients were divided into clozapine-responsive (n = 100) and clozapine-resistant (n = 62) groups based on whether they had achieved psychotic remission defined by the 18-item Brief Psychiatric Rating Scale (BPRS-18). We compared blood orexin-A levels among the three groups and performed regression analysis to determine the association of orexin-A level with treatment response in clozapine-treated patients. We also explored the correlation between orexin-A levels and cognitive function, assessed using the CogState Schizophrenia Battery. Results: Clozapine-responsive patients had higher orexin-A levels than clozapine-resistant and APD-free patients. Orexin-A level was the only factor significantly associated with treatment response after adjustment. Orexin-A levels were negatively correlated with BPRS-18 full scale and positive, negative, and general symptoms subscale scores. We also observed a positive correlation between orexin-A levels and verbal memory, visual learning and memory, and working memory function. Conclusions: This cross-sectional study showed that higher levels of orexin-A are associated with treatment response to clozapine in patients with TRS. Future prospective studies examining changes in orexin-A level following clozapine treatment and the potential benefit of augmenting orexin-A signaling are warranted. [ABSTRACT FROM AUTHOR]

Background and Hypothesis Schizophrenia is associated with widespread cortical thinning and abnormality in the structural covariance network, which may reflect connectome alterations due to treatment effect or disease progression. Notably, patients with treatment-resistant schizophrenia (TRS) have stronger and more widespread cortical thinning, but it remains unclear whether structural covariance is associated with treatment response in schizophrenia. Study Design We organized a multicenter magnetic resonance imaging study to assess structural covariance in a large population of TRS and non-TRS, who had been resistant and responsive to non-clozapine antipsychotics, respectively. Whole-brain structural covariance for cortical thickness was assessed in 102 patients with TRS, 77 patients with non-TRS, and 79 healthy controls (HC). Network-based statistics were used to examine the difference in structural covariance networks among the 3 groups. Moreover, the relationship between altered individual differentiated structural covariance and clinico-demographics was also explored. Study Results Patients with non-TRS exhibited greater structural covariance compared with HC, mainly in the fronto-temporal and fronto-occipital regions, while there were no significant differences in structural covariance between TRS and non-TRS or HC. Higher individual differentiated structural covariance was associated with lower general scores of the Positive and Negative Syndrome Scale in the non-TRS group, but not in the TRS group. Conclusions These findings suggest that reconfiguration of brain networks via coordinated cortical thinning is related to treatment response in schizophrenia. Further longitudinal studies are warranted to confirm if greater structural covariance could serve as a marker for treatment response in this disease. [ABSTRACT FROM AUTHOR]

Managing schizophrenia with clozapine poses a significant challenge due to prevalent therapeutic failures. The increasing interest in personalized medicine underscores the importance of integrating pharmacogenetic information for effective pharmacotherapeutic monitoring in patients. The objective of this study was to explore the correlation between DRD2, HTR2A, SLC6A4, CYP1A2, and ABCB1 polymorphisms and clozapine response in 100 patients with Treatment-Resistant Schizophrenia. Different scales such as the Positive and Negative Syndrome Scale (PANSS), the Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS), the Global Assessment of Functioning Scale (GAF), the Brief Negative Symptom Scale (BNSS), and pharmacokinetic parameters were used to analyse the efficacy of the treatment. Patients who exclusively responded to clozapine compared to the patients with augmentation strategies exhibited distinctive features, such as lower doses, plasma levels, and presented less-pronounced symptomatology. Genetic associations were explored, highlighting SLC6A4, HTR2A, and the *1F/*1F polymorphism for the CYP1A2 gene. [ABSTRACT FROM AUTHOR]

The present network meta-analysis (NMA) was conducted to compare and generate evidence for the most efficacious treatment among available pharmacological interventions for treatment-resistant schizophrenia (TRS). Reviewers extracted data from 47 studies screened from PubMed/MEDLINE, Embase, Cochrane databases and clinical trial registries fulfilling the eligibility criteria. Random effects Bayesian NMA was done with non-informative priors. Network geometry was visualized, and node splitting was done for the closed triangles. Standardized mean difference and 95% credible interval(95%CrI) were reported for the reduction in symptom severity scores. The probability of each intervention for each rank was plotted. Meta-regression was done for the duration of the therapy. Augmentation of antipsychotics with escitalopram (SMD: −1.7[95%CrI: −2.8, −0.70]), glycine (SMD: −1.2 [95%CrI: −2.2, −0.28]) and Yokukansan (SMD: −1.3 [95%CrI: −2.4, −0.24]) shows a statistically significant reduction in symptom severity when compared to clozapine. As per surface under cumulative ranking curve analysis, escitalopram in combination with antipsychotics appeared to be the best intervention with moderate certainty of evidence. There was no significant effect of the duration of therapy on the treatment effects. Escitalopram augmentation of antipsychotics appears to be the most efficacious treatment with moderate certainty of evidence among the available pharmacological interventions. CRD42022380292 [ABSTRACT FROM AUTHOR]

Objectives: To study the differences in side effects of clozapine between older adults aged ≥55 years and younger adults aged 18–55 years with treatment‐resistant schizophrenia. Methods: A retrospective cohort study in a large mental health institute in the Netherlands. All patients diagnosed with treatment‐resistant schizophrenia who started with clozapine between 2011 and 2020 (N = 284) were included. We compared the number and type of side effects reported in the electronic patient files as well as the number of treatment discontinuations and the time until discontinuation, both due to side effects, of older adults versus younger adults. Results: In the younger age group (N = 183), the number of reported side effects was significantly higher in the first 3 months of treatment (Mann–Whitney U = 7341.5, p = 0.004) and after those 3 months (Mann–Whitney U = 5668.5, p < 0.001) compared with the number reported in the older age group (N = 101). Sedation, hypersalivation, dizziness, tachycardia, heartburn, nausea, weight gain, and constipation were reported significantly more often in the younger age group, and only extrapyramidal symptoms were reported significantly more often in the older age group. There was no significant difference in the number of treatment discontinuations due to side effects (23% vs. 21.8%, Chi‐2 = 0.051, df = 1, p = 0.821) and time until discontinuation due to side effects (b = 0.091, SE = 0.335, p = 0.798) between younger and older adults. Conclusions: Side effects of clozapine were reported significantly less often in older patients compared with younger patients. Older patients did not discontinue treatment due to side effects more often or earlier than younger patients. Older patients with schizophrenia may not be more vulnerable to side effects than younger adults. Key points: Only a few studies are published on the use of clozapine in older patients with treatment‐resistant schizophrenia.Contrary to our expectations, side effects of clozapine were reported significantly less often in older patients compared with younger patients and discontinuation rates did not differ significantly.This study suggest that older patients with treatment‐resistant schizophrenia may not be more vulnerable, and perhaps are even less vulnerable, to side effects than younger adults. [ABSTRACT FROM AUTHOR]

The article explores the potential use of neuromelanin-sensitive MRI (NM-MRI) as a biomarker for treatment-resistant schizophrenia. Treatment-resistant schizophrenia refers to patients who do not respond to initial antipsychotic medications. NM-MRI, which measures dopamine function, has shown promise in identifying nonresponders in previous studies. A recent study compared NM-MRI in responders and nonresponders to antipsychotic treatment and found significant differences in certain brain regions. However, the study has limitations, and more research is needed to confirm NM-MRI as a biomarker for treatment-resistant schizophrenia. [Extracted from the article]

Introduction Clozapine, a second-generation antipsychotic (SGA), is considered the gold standard medication to treat patients with treatment-resistant schizophrenia (TRS). Despite its efficacy, clozapine is associated with adverse effects, notably neutropenia and agranulocytosis. Other hematological adverse effects are less common. Severe anemia is a rare adverse effect seldom reported in the literature and is typically associated with pure red cell aplasia (PRCA). Nevertheless, the benefits of clozapine in managing TRS make rechallenge a reasonable option. Case Report We present the case of a 35-year-old man with TRS, resistant to previous antipsychotics, who experienced severe anemia during clozapine treatment. An investigation for clozapine-induced anemia revealed PRCA on myelogram. After discontinuing clozapine, the patient's hemoglobin levels recovered. Subsequent treatments with olanzapine, zuclopenthixol, and aripiprazole proved ineffective, leading us to consider a clozapine rechallenge. The rechallenge, monitored for 58 days, resulted in improved psychiatric symptoms and stable hemoglobin levels. The patient remained stable during 6 months of follow-up, with no hematological changes. Discussion PRCA is a very rare adverse effect of clozapine. The cause of drug-induced PRCA is still unknown; for clozapine, there are no studies. Rechallenge after a severe and rare adverse effect is a complex decision. This case is the first to report a successful clozapine rechallenge following severe anemia without other blood dyscrasias, emphasizing the imperative need for close monitoring during the rechallenge process. Further study is warranted to understand the predictive factors for a successful outcome in clozapine rechallenges. [ABSTRACT FROM AUTHOR]

Introduction: No study has investigated the impact of smoking habits and concomitant valproic acid (VPA) use on clinical outcomes in maintenance treatment with clozapine. Thus, we aimed to examine the effect of smoking habits and concomitant VPA use on relapse during the first year after discharge in patients with treatment‐resistant schizophrenia (TRS) receiving clozapine. Methods: This retrospective cohort study included patients with TRS who were initiated on clozapine during hospitalization and discharged between April 2012 and January 2021 in two tertiary psychiatric hospitals in Japan. Relapse was defined as rehospitalization due to psychiatric exacerbation during the first year after discharge. A multivariable Cox proportional hazards regression analysis was performed to analyze the effect of smoking habits and concomitant VPA use on relapse. Subgroup analyses were also conducted to examine potential interactions between smoking habits and concomitant VPA use. Results: Among the included 192 patients, 69 (35.9%) met the criteria of relapse. While smoking habits (adjusted hazard ratio [aHR], 2.27; 95% confidence interval [CI], 1.28–4.01; p < 0.01) independently increased the risk of relapse, a significant interaction for relapse risk was found between smoking habits and concomitant VPA use (p‐interaction = 0.015). Concomitant VPA use may be an effective modifier of the increased relapse risk associated with smoking habits. Among patients who smoked, those using VPA concomitantly exhibited a higher risk of relapse (aHR, 5.32; 95% CI, 1.68–16.9; p < 0.01) than those not using VPA (aHR, 1.41; 95% CI, 0.73–2.70; p = 0.30). Conclusion: The findings suggest that the combination of smoking habits and concomitant VPA use may increase the risk of relapse after discharge. Future studies are required to elucidate the mechanisms underlying these findings, such as a decrease in clozapine blood levels. [ABSTRACT FROM AUTHOR]

• Daily clozapine dose schedule has no impact on clinical outcomes in patients. • Higher daily clozapine dose level, poorer cognitive function. • Daily clozapine dose schedule has no impact on cognitive function. • Patient with lower daily clozapine dose benefit from a divided dose for cognition. • Clozapine monotherapy is better for vocational functional with high daily dose. Clozapine is the only medication found to be effective for patients with treatment resistant schizophrenia-spectrum disorders (TRS) and its prescription patterns may impact on their outcomes. The study aims to explore the impact of clozapine dosing frequency, dose level and presence of pharmacological augmentation on the clinical, social and cognitive outcomes in patients with TRS. Patients with TRS and on clozapine were interviewed. Daily defined dose (DDD) and anticholinergic burden were calculated. Patients were categorized in three ways: the single daily dose (SDD) and multiple daily dose (MDD), ≤300 mg/day (LD) and >300 mg/day (HD) of clozapine, and clozapine monotherapy (MT) and augmentation therapy (AT). The impact of these clozapine prescription patterns and their interaction on patient outcomes were examined with ANOVA. Of 124 patients on clozapine, 98 patients (79%) had SDD, 59 patients (47.6%) received LD, and 58 patients (46.8%) had MT. Patients in the LD group had significantly better cognitive functions. Though no significant effect of clozapine dosing frequency on outcomes, among patients on LD, those on MDD had better processing speed, short-term and visual memory. Patients with MT had better motivation. Among patients on HD, those with MT had better motivation and vocational functioning. These results provide guidance to the clozapine prescription in a naturalistic setting to achieve optimizing outcomes for patients with TRS in social and cognitive functions. Further longitudinal studies are needed to verify the results. [ABSTRACT FROM AUTHOR]

Evidence regarding effectiveness and safety of clozapine once- vs. multiple-daily dosing is limited. We compared demographic and clinical parameters between patients with once- vs. multiple-daily dosing in the Department of Psychiatry and Psychotherapy, University of Regensburg, Germany (AGATE dataset), and the Department of Psychiatry, Lausanne University Hospital, Switzerland, using non-parametric tests. Effectiveness and safety outcomes were available in the AGATE dataset. We performed a systematic review in PubMed/Embase until February 2022, meta-analyzing studies comparing clozapine once- vs. multiple-daily-dosing. We estimated a pooled odds ratio for adverse drug-induced reactions (ADRs) and meta-analyzed differences regarding clinical symptom severity, age, percentage males, smokers, clozapine dose, and co-medications between patients receiving once- vs. multiple-daily dosing. Study quality was assessed using the Newcastle–Ottawa-Scale. Of 1494 and 174 patients included in AGATE and Lausanne datasets, clozapine was prescribed multiple-daily in 74.8% and 67.8%, respectively. In the AGATE cohort, no differences were reported for the clinical symptoms severity or ADR rate (p > 0.05). Meta-analyzing eight cohorts with a total of 2810 clozapine-treated individuals, we found more severe clinical symptoms (p = 0.036), increased ADR risk (p = 0.01), higher clozapine doses (p < 0.001), more frequent co-medication with other antipsychotics (p < 0.001), benzodiazepines (p < 0.001), anticholinergics (p = 0.039), and laxatives (p < 0.001) in patients on multiple- vs. once-daily dosing. Of six studies, five were rated as good, and one as poor quality. Patients responding less well to clozapine may be prescribed higher doses multiple-daily, also treated with polypharmacy, potentially underlying worse safety outcomes. Patient preferences and adherence should be considered during regimen selection. [ABSTRACT FROM AUTHOR]

Although clozapine demonstrates unique efficacy for treatment-resistant schizophrenia, its impact on community-based services remains largely underexplored. The authors examined changes in use of community-based services after clozapine treatment among a sample of 163 patients with schizophrenia by using public claims data in Allegheny County, Pennsylvania. Mirror-image analyses of service utilization were used to compare the 180-day period before treatment initiation with the 180-day period that began after 6 months of adherent treatment, accounting for age, race, and gender. Across demographic variables, clozapine treatment was associated with increased use of community-based services and decreased use of psychiatric inpatient services (p<0.05, Bonferroni corrected), suggesting that clozapine treatment shifts service needs from emergency care to community-based care and recovery. [ABSTRACT FROM AUTHOR]

Abstract Background Low-grade inflammation and altered inflammatory markers have been observed in treatment-resistant schizophrenia (TRS). Interleukin-6 (IL-6) is one of the pro-inflammatory cytokines linked with TRS and receives increasing attention. Previous studies showed that patients with TRS might have higher IL-6 levels compared with healthy individuals and treatment-responsive patients. Besides, emerging evidence has suggested that there are sex differences in the associations between IL-6 levels and various illnesses, including chronic hepatitis C, metabolic syndrome, etc.; however, there is limited study on TRS. In this present study, we aimed to compare the serum IL-6 levels of TRS and partially responsive schizophrenia (PRS) and explore potential sex differences in the association of TRS and IL-6 levels. Methods The study population consisted of a total of 90 patients with schizophrenia: 64 TRS patients (45.3% males and 54.7% females) and 26 PRS patients (46.2% males and 53.8% females). We measured serum IL-6 levels using enzyme-linked immunosorbent assay (ELISA) and analyzed them separately by gender, controlling for confounders (age, education, medication, body mass index, and PANSS scores) rigorously. Result The results showed that patients with TRS had higher serum IL-6 levels than patients with PRS (p = 0.002). In females, IL-6 levels increased significantly in the TRS group compared with the PRS group (p = 0.005). And a positive correlation tendency was observed between IL-6 levels and PANSS general sub-scores (r = 0.31, p = 0.039), although this correlation was not significant after correcting for multiple comparisons. Whereas, there were no differences in IL-6 levels between the TRS and PRS (p = 0.124) in males. Conclusion Our findings provided evidence supporting the hypothesis that the inflammatory response system (IRS) may play a role in the pathogenesis of TRS in a sex-dependent manner. In addition, sex differences in the immune dysfunction of individuals with schizophrenia cannot be neglected, and inflammation in male and female TRS should be discussed separately.

Abstract Background The optimal treatment strategy for patients with treatment‐resistant schizophrenia (TRS) associated with 22q11.2 deletion syndrome (DS) remains a subject of debate. Case Presentation We present the case of a 40‐year‐old female patient diagnosed with TRS and 22q11.2DS who was effectively treated with clozapine. She was diagnosed with schizophrenia and mild intellectual disability during her adolescence; despite being hospitalized for a period of 10 years beginning in her 30s, she continued to exhibit symptoms of impulsivity, and explosive behavior, requiring periods of isolation. We ultimately decided to switch her medication to clozapine, which was administered with caution and gradually titrated upward, with no discernable adverse effects, resulting in a marked improvement in her symptoms and obviated the need for isolation. Subsequently, the patient's history of congenital heart disease and facial abnormalities prompted initial suspicions of a 22q11.2DS diagnosis, which was subsequently confirmed through genetic testing. Conclusion Clozapine may serve as an efficacious pharmacological intervention for TRS patients with 22q11.2DS, including those of Asian descent.

Background: Clozapine is the only Food and Drug Administration (FDA) and National Institute for Care and Excellence (NICE) approved drug for treatment-resistant schizophrenia (TRS). Its potentially life-threatening haematological side effects of neutropaenia and agranulocytosis mandate rigorous monitoring of neutrophil counts, presenting unique, Third-World population challenges. Aim: To describe the Clozapine white blood cell monitoring practice and outcomes in a local psychiatric hospital. Setting: At a specialist Psychiatry unit in Durban, KwaZulu-Natal, which follows a modified algorithm of the South African Standard Treatment Guidelines for Clozapine monitoring. Methods: A retrospective chart review composed of 120 patients on Clozapine treatment from 01 July 2018–31 December 2020. Demographic and clinical information was captured in a Redcap database. Descriptive statistics using categorical variables were used. Results: The study population was from a low socioeconomic background, with low levels of education and employment. A baseline neutrophil count was recorded in 58 files (48.3%). Clozapine was stopped in 6 out of the 120 patients due to ‘neutropaenia’ (absolute neutrophil counts ranging from 1.18 to 1.6); none developed agranulocytosis. Their duration of Clozapine treatment ranged from 2 weeks–15 years. Conclusion: Haematological monitoring frequency and documentation of patients receiving Clozapine were not in compliance with the hospital’s adapted guidelines and may have resulted in the termination of treatment before true neutropaenia developed. Patients developed neutropaenia at low doses of Clozapine and after many years of treatment. Contribution: These results suggest local Clozapine monitoring guidelines should be more strictly adhered to.

Clozapine is listed as one of the most effective antipsychotics and has been approved for treating treatment-resistant schizophrenia (TRS); however, several type A and B adverse reactions, including weight gain, metabolic complications, cardiotoxicity, convulsions, and discontinuation syndromes, exist. The critical mechanisms of clinical efficacy for schizophrenia, TRS, and adverse reactions of clozapine have not been elucidated. Recently, the GABA isomer L-β-aminoisobutyric acid (L-BAIBA), a protective myokine in the peripheral organs, was identified as a candidate novel transmission modulator in the central nervous system (CNS). L-BAIBA activates adenosine monophosphate-activated protein kinase (AMPK) signalling in both the peripheral organs and CNS. Activated AMPK signalling in peripheral organs is an established major target for treating insulin-resistant diabetes, whereas activated AMPK signalling in the hypothalamus contributes to the pathophysiology of weight gain and metabolic disturbances. Clozapine increases L-BAIBA synthesis in the hypothalamus. In addition, the various functions of L-BAIBA in the CNS have recently been elucidated, including as an activator of GABA-B and group-III metabotropic glutamate (III-mGlu) receptors. Considering the expressions of GABA-B and III-mGlu receptors (localised in the presynaptic regions), the activation of GABA-B and III-mGlu receptors can explain the distinct therapeutic advantages of clozapine in schizophrenia or TRS associated with N-methyl-D-aspartate (NMDA) receptor disturbance compared with other atypical antipsychotics via the inhibition of the persistent tonic hyperactivation of thalamocortical glutamatergic transmission in the prefrontal cortex. L-BAIBA has also been identified as a gliotransmitter, and a detailed exploration of the function of L-BAIBA in tripartite synaptic transmission can further elucidate the pathophysiology of effectiveness for treating TRS and/or specific adverse reactions of clozapine. [ABSTRACT FROM AUTHOR]