Predictors of clozapine response in patients with treatment-refractory schizophrenia: results from a Danish Register Study

Clozapine as a mood stabiliser for schizoaffective disorder: Effectiveness during a three-month follow-up

Clozapine has shown signs of effectiveness in treating symptoms of schizoaffective disorder, although little research has been carried out to specifically assess this question. The objective of this current work was to analyse the mood-stabilising effectiveness and tolerability of clozapine in patients with schizoaffective disorder. This was a prospective, longitudinal, and quasi-experimental trial with three months of follow-up in patients with refractory schizoaffective disorder (PANSS score exceeding 80). Clinical response was evaluated through monthly visits using the YMRS, MADRS, CDSS, CGI-S and UKU. Twenty-seven participants (63% men, 37% women) with a mean age of 32.56 years were included. Clozapine significantly reduced the symptoms of mania, as measured by the YMRS (pre-treatment: 16.19, post-treatment: 0.67; p < 0.01) as well as the symptoms of depression, quantified with the CDSS (pre-treatment: 6.11, post-treatment: 0.67; p < 0.01), MADRS (pre-treatment: 9.56, post-treatment: 1.07; p < 0.01), and CGI-S (pre-treatment: 4.74, post-treatment: 1.15; p < 0.01). The prescription of clozapine significantly reduced the average daily dose of neuroleptics, measured in mg of chlorpromazine (pre-treatment: 1253.55, post-treatment: 742.59; p < 0.01) and hypnosedatives, measured in mg of diazepam (pre-treatment: 33.88, post-treatment: 5.74; p < 0.05) required in these patients. Patient-perceived tolerability, measured with the UKU, also improved during follow-up (pre-treatment: 12.89, post-treatment: 8.14; p < 0.01). The efficacy of clozapine was significant for the affective symptoms of schizoaffective disorder, thereby improving patient tolerability and permitting reductions in the other medications the patients used.

Overcoming the barriers to identifying and managing treatment-resistant schizophrenia and to improving access to clozapine: A narrative review and recommendation for clinical practice

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.

Umbrella Review: Atlas of the Meta-Analytical Evidence of Early-Onset Psychosis

OBJECTIVE

Early-onset psychosis (EOP) refers to the development of psychosis before the age of 18 years. We aimed to summarize, for the first time, the meta-analytical evidence in the field of this vulnerable population and to provide evidence-based recommendations.

METHOD

We performed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant, pre-registered (PROSPERO: CRD42022350868) systematic review of several databases and registers to identify meta-analyses of studies conducted in EOP individuals to conduct an umbrella review. Literature search, screening, data extraction, and quality assessment were carried out independently. Results were narratively reported, clustered across core domains. Quality assessment was performed with the Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) tool.

RESULTS

A total of 30 meta-analyses were included (373 individual studies, 25,983 participants, mean age 15.1 years, 38.3% female). Individuals with EOP showed more cognitive impairments compared with controls and individuals with adult/late-onset psychosis. Abnormalities were observed meta-analytically in neuroimaging markers but not in oxidative stress and inflammatory response markers. In all, 60.1% of EOP individuals had a poor prognosis. Clozapine was the antipsychotic with the highest efficacy for overall, positive, and negative symptoms. Tolerance to medication varied among the evaluated antipsychotics. The risk of discontinuation of antipsychotics for any reason or side effects was low or equal compared to placebo.

CONCLUSION

EOP is associated with cognitive impairment, involuntary admissions, and poor prognosis. Antipsychotics can be efficacious in EOP, but tolerability and safety need to be taken into consideration. Clozapine should be considered in EOP individuals who are resistant to 2 non-clozapine antipsychotics. Further meta-analytical research is needed on response to psychological interventions and other prognostic factors.

PLAIN LANGUAGE SUMMARY

This umbrella review summarized the meta-analytical knowledge from 30 meta-analyses on early-onset psychosis. Early-onset psychosis refers to the development of psychosis before the age of 18 years and is associated with cognitive impairment, hospitalization, and poor prognosis. Individuals with early-onset psychosis show more cognitive impairments and abnormalities compared with controls. Clozapine was the antipsychotic with the highest efficacy for positive, negative, and overall symptoms and should be considered in individuals with early-onset psychosis.

STUDY PREREGISTRATION INFORMATION

Early Onset Psychosis: Umbrella Review on Diagnosis, Prognosis and Treatment factors; https://www.crd.york.ac.uk/PROSPERO/; CRD42022350868.

Revealing the reporting disparity: VigiBase highlights underreporting of clozapine in other Western European countries compared to the UK

BACKGROUND

Pharmacovigilance studies indicate clozapine history is marked by adverse drug reactions (ADRs).

OBJECTIVE

In a 2021 article, the United Kingdom (UK) had >90 % of European clozapine-related fatal outcomes in VigiBase, the World Health Organization's pharmacovigilance database. Two possibly opposing hypotheses could explain this disparity: 1) fewer reported fatal outcomes in other Western European countries mainly reflect underreporting to VigiBase, and 2) the higher number of UK reports reflects higher real relative mortality.

METHODS

VigiBase reports from clozapine's introduction to December 31, 2022, were studied for ADRs and the top 10 causes of fatal outcomes. The UK was compared with 11 other top reporting Western countries (Germany, Denmark, France, Finland, Ireland, Italy, Netherlands, Norway, Spain, Sweden and Switzerland). Nine countries (except Ireland and Switzerland) were compared after controlling for population and clozapine prescriptions.

RESULTS

The UK accounted for 29 % of worldwide clozapine-related fatal outcomes, Germany 2 % and <1 % in each of the other countries. The nonspecific label "death" was the top cause in the world (46 %) and in the UK (33 %). "Pneumonia" was second in the world (8 %), the UK (12 %), Ireland (8 %) and Finland (14 %). Assuming that our corrections for population and clozapine use are correct, other countries underreported only 1-10 % of the UK clozapine fatal outcome number.

CONCLUSIONS

Different Western European countries consistently underreport to VigiBase compared to the UK, but have different reporting/publishing styles for clozapine-related ADRs/fatal outcomes. Three Scandinavian registries suggest lives are saved as clozapine use increases, but this cannot be studied in pharmacovigilance databases.

[Management of treatment resistance-Treatment-resistant schizophrenia]

Despite a very high prevalence and substantial impairments among affected individuals, treatment-resistant schizophrenia (TRS) has not been sufficiently researched in clinical research in the field of psychiatric disorders and the pathophysiology is still poorly understood. A better clinical and pathophysiological understanding of this heterogeneous and severely affected population of people with persistent symptoms in different domains is necessary in order not only to be able to intervene early but also to develop novel therapeutic strategies or individualized treatment approaches. This review article presents the state of the art criteria of the pharmacological TRS, neurobiological disease models and predictive factors for TRS as well as the phenomenon of pseudo-treatment resistance and the clinical management of TRS. In the future, not only the use of operationalized criteria and definitions of TRS in longitudinal studies and randomized-controlled trials (RCTs) are paramount, but also the observation of trajectories with the integration of multimodal longitudinal phenotyping and the longitudinal collection of clinical routine data in academic research, which will be possible in the newly created German Center for Mental Health (DZPG).

Sex differences in effectiveness and adverse effects of mood stabilizers and antipsychotics: A systematic review

BACKGROUND

Psychiatric disorders differ in their prevalence, symptom profiles, and disease courses in men and women. However, sex differences in psychiatric disorders have not received enough attention to guide treatment recommendations. This systematic review aims to summarize sex differences in the treatment responses and adverse effects of mood stabilizers and antipsychotics transdiagnostically.

METHODS

We conducted a systematic review following the PRISMA 2020 statement (CRD42020212478). A literature search was conducted using MEDLINE, Embase, Cochrane Central, PsycINFO, Web of Science Core Collection, and Scopus databases. Studies comparing mood stabilizer or antipsychotic treatment outcomes in men and women were included. JBI critical appraisal checklists were used to assess bias risk.

RESULTS

Out of 4866 records, 129 reports (14 on mood stabilizers, 115 on antipsychotics) with varying designs were included. Sample sizes ranged from 17 to 22,774 participants (median = 147). The most common psychiatric diagnoses were schizophrenia spectrum (n = 109, 84.5 %) and bipolar disorders (n = 38, 29.5 %). Only four studies explored sex differences in mood stabilizer treatment response. In 40 articles on antipsychotic treatment response, 18 indicated no sex difference, while 16 showed females had better outcomes. Women had more adverse effects with both mood stabilizers and antipsychotics. The risk of bias was low in 84 (65.1 %) of studies.

LIMITATIONS

Substantial heterogeneity among the studies precluded performing a meta-analysis.

CONCLUSION

Number of studies focusing on sex differences in treatment outcomes of mood stabilizers is limited. Women may respond better to antipsychotics than men, but also experience more side effects. The impact of pharmacokinetics on sex differences warrants more attention.

Schizophrenia patients discharged on antipsychotic polypharmacy from a public psychiatric hospital in Taiwan, 2006-2021

The aim of this study was to identify the factors associated with antipsychotic polypharmacy (APP), investigate whether APP could affect the risk of rehospitalization, and explore temporal trends in APP use. Schizophrenia patients discharged from the study hospital between 2006 and 2021 (n = 16,722) were included in the analysis. The logistic regression model was employed to determine the predictors significantly associated with APP use. Survival analysis was used to compare time to rehospitalization between APP and antipsychotic monotherapy (AMT). The temporal trend of APP use was analyzed using the Cochran-Armitage Trend test. In comparison with the patients (n = 10,909) who were discharged on AMT, those (n = 5,813) on APP were significantly more likely to be male gender, to receive LAIs, to take clozapine, to take anticholinergic agents, to have a greater number of previous hospitalizations, and to have a higher CPZ equivalent dose of antipsychotic prescription. The prescription rate of APP significantly increased from 18.4 % in 2006 to 44.9 % in 2021. Compared with AMT, APP was associated with more clozapine use, more LAI use, higher doses of antipsychotics, and an increased risk of rehospitalization. In addition, the prescription of APP continued to increase during the study period.

An international research agenda for clozapine-resistant schizophrenia

Treatment-resistant symptoms occur in about a third of patients with schizophrenia and are associated with a substantial reduction in their quality of life. The development of new treatment options for clozapine-resistant schizophrenia constitutes a crucial, unmet need in psychiatry. Additionally, an overview of past and possible future research avenues to optimise the early detection, diagnosis, and management of clozapine-resistant schizophrenia is unavailable. In this Health Policy, we discuss the ongoing challenges associated with clozapine-resistant schizophrenia faced by patients and health-care providers worldwide to improve the understanding of this condition. We then revisit several clozapine guidelines, the diagnostic tests and treatment options for clozapine-resistant schizophrenia, and currently applied research approaches in clozapine-resistant schizophrenia. We also suggest methodologies and targets for future research, divided into innovative nosology-oriented field trials (eg, examining dimensional symptom staging), translational approaches (eg, genetics), epidemiological research (eg, real-world studies), and interventional studies (eg, non-traditional trial designs incorporating lived experiences and caregivers' perspectives). Finally, we note that low-income and middle-income countries are under-represented in studies on clozapine-resistant schizophrenia and propose an agenda to guide multinational research on the cause and treatment of clozapine-resistant schizophrenia. We hope that this research agenda will empower better global representation of patients living with clozapine-resistant schizophrenia and ultimately improve their functional outcomes and quality of life.

Early Non-Response to Antipsychotic Treatment in Schizophrenia: A Systematic Review and Meta-Analysis of Evidence-Based Management Options

BACKGROUND

Early non-response is a well-established prognostic marker but evidence-based and consistent recommendations to manage it are limited. The aim of this systematic review and meta-analysis was to generate evidence-based strategies for the management of schizophrenia patients with early non-response to 2 weeks of antipsychotic treatment.

METHODS

We conducted a systematic review and meta-analysis of randomized trials comparing antipsychotic dose escalation, switch, augmentation and continuation in individuals with study-defined early antipsychotic treatment non-response. Eligibility criteria were (1) clinical trials of primary psychosis treating for at least 2 weeks with antipsychotic monotherapy with study-defined operationalized criteria for early non-response; and (2) randomization to at least two of the following treatment strategies: dose escalation, switch, augmentation, or treatment continuation. Information sources were Pubmed, PsycINFO, and EMBASE, and risk of bias was assessed using Jadad scores. Results were synthesized using random-effects meta-analysis, comparing each intervention with treatment continuation for total symptom change as the primary outcome, generating standardized mean differences (SMDs) and 95% confidence intervals (CIs). Studies meeting the selection criteria but providing insufficient data for a meta-analysis were presented separately.

RESULTS

We screened 454 records by 1 August 2022, of which 12 individual datasets met the inclusion criteria, representing 947 research participants. Of those studies, five provided data to include in the meta-analysis (four with early non-response at 2 weeks, one at 3 weeks). Early non-response was defined within a timeline of 2 weeks in eight datasets, with the remaining datasets ranging between 3 and 4 weeks. The rates of early non-response ranged between 72.0 and 24.1%, and the endpoint ranged within 4-24 weeks post randomization. Quality was good (i.e., Jadad score of ≥3) in 8 of the 12 datasets. Overall, three studies compared antipsychotic switch versus continuation and two compared antipsychotic switch versus augmentation, in both cases without significant pooled between-group differences for total symptom severity (n = 149, SMD 0.18, 95% CI -0.14 to 0.5). Individually, two relatively large studies for antipsychotic switch versus continuation found small advantages for switching antipsychotics for total symptom severity (n = 149, SMD -0.49, 95% CI -1.05 to -0.06). One relatively large study found an advantage for dose escalation, although this finding has not been replicated and was not included in the meta-analysis. None of the alternatives included antipsychotic switch to clozapine.

CONCLUSIONS

Despite robust accuracy of early antipsychotic non-response predicting ultimate response, the evidence for treatment strategies that should be used for early non-response after 2-3 weeks is limited. While meta-analytic findings were non-significant, some individual studies suggest advantages of antipsychotic switch or dose escalation. Therefore, any conclusions should be interpreted carefully, given the insufficient high-quality evidence.

What are the barriers and facilitators of clozapine use in early psychosis? A survey of UK early intervention clinicians

Clozapine is the most effective medication for treatment-resistant psychosis, but evidence points to substantial underuse, especially within early intervention psychosis (EIP) services. We explored clinicians' views on perceived barriers and facilitators to offering patients clozapine within EIP services. A cross-sectional survey was distributed electronically to clinicians practising in EIP services across England. A mixed methods approach was used to assess barriers to clozapine, and attitudes and opinions concerning clozapine underutilisation. Based on the barriers identified in the literature, clinicians were asked to rate each one (scale:1-7) based on importance, with a higher score indicating higher importance. Clinicians were also asked open-ended questions on barriers to clozapine and how access can be improved in EIP services. Quantitative data were analysed using descriptive and inferential statistics, and qualitative responses were analysed thematically. One hundred and nineteen EIP clinicians from 35 services in England completed the survey. In total, 37% (n = 45) of clinicians perceived that clozapine was under-prescribed in their EIP service. The most important barrier to utilising clozapine were patient concerns with side effects, followed by monitoring requirements and clinician concerns with side effects. Thematic analysis identified 17 perceived barriers, which were grouped into three major themes: administrative (5 subthemes), clinician-related (6 subthemes), and patient-related (6 subthemes). Perceived facilitators to improving clozapine use were greater training, improved resources, and optimised monitoring. The main barriers to clozapine in EIP services, as identified by clinicians, are patient concerns regarding side effects and monitoring requirements. Identified facilitators for improved clozapine use include clinician training, improved resources, guidelines, and point-of-care testing.

Dopamine supersensitivity psychosis and delay of clozapine treatment in patients with treatment-resistant schizophrenia

Both the underutilization of clozapine and treatment resistance of patients to clozapine are serious problems worldwide. Identifying clinical markers predicting response to clozapine would help clinicians more effectively utilize clozapine treatment. The present study retrospectively assessed dopamine supersensitivity psychosis (DSP) in addition to other measures such as age at disease onset and delay of clozapine introduction for a total of 47 treatment-resistant schizophrenia (TRS) patients. The response to clozapine was judged with CGI-C at 1 and 2 years from clozapine introduction. Results revealed that the DSP group tended to have a longer delay between designation of TRS and introduction of clozapine and continued to have slightly more severe psychopathology after treatment with clozapine, showing only slight improvement. The logistic regression analysis showed that the age at disease onset was the only significant indicator, predicting responsiveness to clozapine: patients with an onset age <20 years had a significantly better response to clozapine than patients with an onset age ≥20 years. The present study suggests that DSP might be related to a longer delay in clozapine introduction and the persistence of refractory symptoms despite clozapine treatment, whereas early age of disease onset might be related to a better response to clozapine.

Sex differences: From preclinical pharmacology to clinical pharmacology

Sex is a crucial variable to take into account in medical research. In this review, we attempted to present its importance at all stages of research and even during drug's post-marketing surveillance. Most preclinical research studies do not take sex into account while many diseases are known to present sexual dimorphism. However, a shift in thinking occurred since the January 2016 implementation of the US Institutes of Health recommendations to take sex into account in research. Nevertheless, in preclinical studies, the lack of sex-based statistical analyses persists. Moreover, in humans, women are often under-represented in some clinical trials, despite well-identified sexual dimorphism. In addition, some pathologies are subject to social representations of diseases considered "male" or "female" which can also lead to a delay in diagnosis and management for both sexes. Finally, many drug classes may be subject to sex differences in efficacy and safety. For example, women present more adverse events than men, mainly because of different pharmacokinetic parameters. Accounting sex as a variable from the preclinical phase is essential to improve the transposition of observed results and move towards personalized medicine.

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.

Women with Schizophrenia-Spectrum Disorders After Menopause: A Vulnerable Group for Relapse

BACKGROUND AND HYPOTHESIS

Throughout the life stages of women with schizophrenia-spectrum disorders (SSD), lower estrogen levels are associated with more severe disease course. At perimenopause in the mid-forties, estrogen levels decline to remain persistently low after menopause. This period is hypothesized to increase relapse risk and reduce antipsychotic effectiveness in preventing relapse.

STUDY DESIGN

The cohort of persons with schizophrenia/schizoaffective disorder was identified from Finnish nationwide registers (N = 61 889) and stratified by sex and age <45 vs. ≥45 years. Hospitalizations for psychosis were defined per 5-year age group during the follow-up 1996-2017. Risk of psychosis hospitalization (Adjusted Hazard Ratio, aHR) was assessed using within-individual design, by comparing antipsychotic monotherapy use to nonuse periods in the same individuals for seven dose categories in defined daily doses (DDDs/day).

RESULTS

Starting at age 45-50, women were consistently more often hospitalized for psychosis than their male peers. Women ≥45 had significantly higher aHRs than women <45 at antipsychotic monotherapy >0.6 DDDs/day, and than men at >1.1 DDDs/day. This female-specific age-dependent decrease in effectiveness was present for clozapine doses >0.6 DDDs/day, olanzapine doses >1.4 DDDs/day, and for specific doses of quetiapine (0.9-1.1 DDDs/day) and risperidone (0.6-0.9 DDDs/day).

CONCLUSIONS

While younger women have a lower risk of relapse and generally need a lower antipsychotic dose to prevent rehospitalization than men, antipsychotic effectiveness declines in women after the age of 45. Starting in mid-forties, older women with SSD should be regarded as a vulnerable group that deserve special attention.

Clozapine's multiple cellular mechanisms: What do we know after more than fifty years? A systematic review and critical assessment of translational mechanisms relevant for innovative strategies in treatment-resistant schizophrenia

Almost fifty years after its first introduction into clinical care, clozapine remains the only evidence-based pharmacological option for treatment-resistant schizophrenia (TRS), which affects approximately 30% of patients with schizophrenia. Despite the long-time experience with clozapine, the specific mechanism of action (MOA) responsible for its superior efficacy among antipsychotics is still elusive, both at the receptor and intracellular signaling level. This systematic review is aimed at critically assessing the role and specific relevance of clozapine's multimodal actions, dissecting those mechanisms that under a translational perspective could shed light on molecular targets worth to be considered for further innovative antipsychotic development. In vivo and in vitro preclinical findings, supported by innovative techniques and methods, together with pharmacogenomic and in vivo functional studies, point to multiple and possibly overlapping MOAs. To better explore this crucial issue, the specific affinity for 5-HT₂R, D1R, α_2c, and muscarinic receptors, the relatively low occupancy at dopamine D2R, the interaction with receptor dimers, as well as the potential confounder effects resulting in biased ligand action, and lastly, the role of the moiety responsible for lipophilic and alkaline features of clozapine are highlighted. Finally, the role of transcription and protein changes at the synaptic level, and the possibility that clozapine can directly impact synaptic architecture are addressed. Although clozapine's exact MOAs that contribute to its unique efficacy and some of its severe adverse effects have not been fully understood, relevant information can be gleaned from recent mechanistic understandings that may help design much needed additional therapeutic strategies for TRS.

A Guideline and Checklist for Initiating and Managing Clozapine Treatment in Patients with Treatment-Resistant Schizophrenia

Treatment-resistant schizophrenia (TRS) will affect about one in three patients with schizophrenia. Clozapine is the only treatment approved for TRS, and patients should be treated as soon as possible to improve their chances of achieving remission. Despite its effectiveness, concern over side effects, monitoring requirements, and inexperience with prescribing often result in long delays that can expose patients to unnecessary risks and compromise their chances of achieving favorable long-term outcomes. We critically reviewed the literature on clozapine use in TRS, focusing on guidelines, systematic reviews, and algorithms to identify strategies for improving clozapine safety and tolerability. Based on this, we have provided an overview of strategies to support early initiation of clozapine in patients with TRS based on the latest evidence and our clinical experience, and have summarized the key elements in a practical, evidence-based checklist for identifying and managing patients with TRS, with the aim of increasing confidence in prescribing and monitoring clozapine therapy.

Using a statistical learning approach to identify sociodemographic and clinical predictors of response to clozapine

BACKGROUND

A proportion of people with treatment-resistant schizophrenia fail to show improvement on clozapine treatment. Knowledge of the sociodemographic and clinical factors predicting clozapine response may be useful in developing personalised approaches to treatment.

METHODS

This retrospective cohort study used data from the electronic health records of the South London and Maudsley (SLaM) hospital between 2007 and 2011. Using the Least Absolute Shrinkage and Selection Operator (LASSO) regression statistical learning approach, we examined 35 sociodemographic and clinical factors' predictive ability of response to clozapine at 3 months of treatment. Response was assessed by the level of change in the severity of the symptoms using the Clinical Global Impression (CGI) scale.

RESULTS

We identified 242 service-users with a treatment-resistant psychotic disorder who had their first trial of clozapine and continued the treatment for at least 3 months. The LASSO regression identified three predictors of response to clozapine: higher severity of illness at baseline, female gender and having a comorbid mood disorder. These factors are estimated to explain 18% of the variance in clozapine response. The model's optimism-corrected calibration slope was 1.37, suggesting that the model will underfit when applied to new data.

CONCLUSIONS

These findings suggest that women, people with a comorbid mood disorder and those who are most ill at baseline respond better to clozapine. However, the accuracy of the internally validated and recalibrated model was low. Therefore, future research should indicate whether a prediction model developed by including routinely collected data, in combination with biological information, presents adequate predictive ability to be applied in clinical settings.

A Comparison of Attitudes, Comfort, and Knowledge of Clozapine Among Two Diverse Samples of US Psychiatrists

Considerable variation in clozapine utilization exists across the United States, and little is known about the perspective of psychiatrists in states with low clozapine use. To better understand clozapine practices, attitudes, and barriers, a survey was administered to a group of southeastern state conference attendees (SSCA; N = 86). The same survey was administered to psychiatrists belonging to a national community psychiatry organization (AACP; N = 57), and differences were analyzed across the two samples. In comparison to the AACP, the SSCA group felt less comfortable, perceived clozapine as less safe and effective, had fewer patients on clozapine, and were more likely to prefer antipsychotic polypharmacy to clozapine use. Across the sample, use of a myocarditis screening protocol was rare (N = 14/76; 18%) and less than half used plasma antipsychotic levels to guide dosage (N = 60/129; 47%). Continuing professional education on clozapine are needed for psychiatrists who see individuals with psychotic disorders.

Bioinformatics and Network-based Approaches for Determining Pathways, Signature Molecules, and Drug Substances connected to Genetic Basis of Schizophrenia etiology

Knowledge of heterogeneous etiology and pathophysiology of schizophrenia (SZP) is reasonably inadequate and non-deterministic due to its inherent complexity and underlying vast dynamics related to genetic mechanisms. The evolution of large-scale transcriptome-wide datasets and subsequent development of relevant, robust technologies for their analyses show promises toward elucidating the genetic basis of disease pathogenesis, its early risk prediction, and predicting drug molecule targets for therapeutic intervention. In this research, we have scrutinized the genetic basis of SZP through functional annotation and network-based system biology approaches. We have determined 96 overlapping differentially expressed genes (DEGs) from 2 microarray datasets and subsequently identified their interconnecting networks to reveal transcriptome signatures like hub proteins (FYN, RAD51, SOCS3, XIAP, AKAP13, PIK3C2A, CBX5, GATA3, EIF3K, and CDKN2B), transcription factors and miRNAs. In addition, we have employed gene set enrichment to highlight significant gene ontology (e.g., positive regulation of microglial cell activation) and relevant pathways (such as axon guidance and focal adhesion) interconnected to the genes associated with SZP. Finally, we have suggested candidate drug substances like Luteolin HL60 UP as a possible therapeutic target based on these key molecular signatures.

Clozapine for treatment resistance in early psychosis: a survey of UK clinicians' training, knowledge and confidence

BACKGROUND

Clozapine is the only medication licenced for patients with psychosis that is resistant to conventional antipsychotic treatment. However, despite its effectiveness, it remains widely underutilised. One contributory factor for this may be clinicians' lack of confidence around the management of clozapine.

OBJECTIVE

We conducted a survey of clinicians working in Early Intervention in Psychosis (EIP) services to determine their training needs for clozapine management in EIP services.

METHODS

An electronic survey was made available to all clinicians working in EIP services in England. The survey assessed confidence and training needs regarding managing clozapine in patients with treatment-resistant psychosis. Quantitative data were analysed using total mean scores and the Mann-Whitney U test.

RESULTS

In all, 192 (27%) of approximately 700 clinicians from 35 EIP services completed the survey. Approximately half (54%) had not received training on treatment with clozapine. Experience of training was higher in prescribers than non-prescribers, and among medical than non-medical clinicians. Previous training was associated with significantly higher confidence in offering clozapine and managing treatment-resistant psychosis (p < 0.001). Confidence levels with managing treatment-resistant psychosis and clozapine were relatively high (mean = 4 out of 5, SD = 1). Respondents were most confident about monitoring mental health response to treatment (mean = 5, SD = 1). Participants were least confident about how to discontinue clozapine treatment safely (mean = 3, SD = 1).

CONCLUSION

Most clinicians working in EIP have not received training on the use of clozapine. This may account, in part, for the underutilisation of clozapine in EIP services. The provision of training in the identification of treatment-resistant psychosis and the use of clozapine will likely improve the detection and management of treatment resistance in the early phase of psychosis.

Clozapine Response in Schizophrenia and Hematological Changes

BACKGROUND

Clozapine is the only effective medication for treatment-resistant schizophrenia; however, its mechanism of action remains unclear. The present study explored whether its effectiveness is related to changes in hematological measures after clozapine initiation.

METHODS

Patients with treatment-resistant schizophrenia commenced on clozapine between January 2007 and December 2014 by the United Kingdom's largest mental health trust were identified from electronic patient records. Hematological data from these patients were obtained from a monitoring registry. White blood cell, neutrophil, and platelet count were assessed at baseline and during the early phase of clozapine treatment. Clozapine response at 3 months was defined as "much," or "very much" improved on the seven-point Clinical Global Impression-Improvement (CGI-I) subscale.

RESULTS

In the total sample (n = 188), clozapine initiation was associated with a significant transient increase (peaking in weeks 3 to 4) in white blood cell, neutrophil, and platelet count (P < 0.001). There were 112 (59.6%) patients that responded to treatment; however, none of the hematological factors assessed at baseline, nor changes in these factors, were directly associated with treatment response.

IMPLICATIONS

Clozapine treatment is associated with transient hematological changes during the first month of treatment; however, there was no evidence that these were related to the therapeutic response.

A Chart Audit Study of Clozapine Utilization in Early Psychosis

PURPOSE

This study aimed to document the treatment trajectories and clozapine use in first-episode psychosis patients and to document the underlying reasons for using or not using clozapine in patients not achieving psychosis remission.

METHODS

We conducted a retrospective chart audit of patients aged 18 to 30 years having DSM-5 diagnoses of schizophrenia spectrum psychotic disorders treated in 3 Canadian early intervention programs for psychosis. The severity of the patient's illness (using the Clinical Global Impression Severity [CGI-S] scale) and remission of psychosis were rated before and after each antipsychotic trial.

RESULTS

One hundred and forty-seven patients were included in the study. There were 19.7% patients exposed to clozapine after an average of 2.4 antipsychotic trials and a mean delay of 470.8 days. There were 75.9% patients who improved their CGI-S score (mean improvement, 2.5) after the clozapine trial and 62.1% achieved a CGI-S score ≤3. Full remission of psychosis on clozapine was achieved in 69.0% of the patients. Clozapine was successfully used for some patients with a nonadherent profile in our sample (eg, personality disorder, substance use disorder). Although the mean duration of clozapine trials during the observation period was 688.6 days, no patient discontinued clozapine because of adherence issues.

CONCLUSIONS

Clozapine use in these early intervention programs were at a rate consistent to what is expected from the literature and allowed a majority of patients to achieve remission of psychosis and to experience a robust improvement of severity of illness.

Clozapine tolerability in Treatment Resistant Schizophrenia: exploring the role of sex

Clozapine is the only evidence-based drug indicated for Treatment Resistant Schizophrenia but it is largely underprescribed, partially due to its life-threatening adverse effects (AEs). However, clozapine treatment is burdened by other common AEs as constipation, hypersalivation, postural hypotension, tachycardia and metabolic abnormalities. Few studies have investigated sex-related differences in clozapine's tolerability, reporting women to experience more frequently weight gain, hyperglycemia and constipation, while men hypertension and dyslipidemia. Based on these premises, we investigated clinical, psychopathological and metabolic sex-related differences among 147 treatment-resistant patients treated with clozapine, with a specific focus on non-life-threatening AEs. We observed significant higher prevalence of tachycardia in men, and of orthostatic hypotension and constipation in women. Concerning metabolic alterations, we observed significant lower levels of HDL-cholesterol and higher prevalence of hypertriglyceridemia among men, whereas females showed higher prevalence of abdominal obesity. Consistently with previous studies, our data confirm the presence of sex-related differences in clozapine tolerability, with a main effect of sex especially for tachycardia, postural hypotension and constipation. Although non-life-threatening, these common AEs significantly affect patients' quality of life, undermine compliance and cause treatment discontinuation. A better understanding of this topic could contribute to tailor therapeutic approaches, thus improving tolerability, compliance and clinical stability.

Demographic and clinical variables associated with response to clozapine in schizophrenia: a systematic review and meta-analysis

Clozapine is the only licensed pharmacotherapy for treatment-resistant schizophrenia. However, response to clozapine is variable. Understanding the demographic and clinical features associated with response to clozapine may be useful for patient stratification for clinical trials or for identifying patients for earlier initiation of clozapine. We systematically reviewed the literature to investigate clinical and demographic factors associated with variation in clozapine response in treatment-resistant patients with schizophrenia spectrum disorders. Subsequently, we performed a random-effects meta-analysis to evaluate differences in duration of illness, age at clozapine initiation, age of illness onset, body weight and years of education between clozapine responders and non-responders. Thirty-one articles were eligible for qualitative review and 17 of these were quantitatively reviewed. Shorter duration of illness, later illness onset, younger age at clozapine initiation, fewer hospitalisations and fewer antipsychotic trials prior to clozapine initiation showed a trend to be significantly associated with a better response to clozapine. Meta-analysis of seven studies, totalling 313 subjects, found that clozapine responders had a significantly shorter duration of illness compared to clozapine non-responders [g = 0.31; 95% confidence interval (CI) 0.06-0.56; p = 0.01]. The results imply that a delay in clozapine treatment may result in a poorer response and that a focus on prompt treatment with clozapine is warranted.

Possible pharmacogenetic factors in clozapine treatment failure: a case report

There is still much to learn about the predictors of therapeutic response in psychiatry, but progress is gradually being made and precision psychiatry is an exciting and emerging subspeciality in this field. This is critically important in the treatment of refractory psychotic disorders, where clozapine is the only evidence-based treatment but only about half the patients experience an adequate response. In this case report, we explore the possible biological mechanisms underlying treatment failure and discuss possible ways of improving clinical outcomes. Further work is required to fully understand why some patients fail to respond to the most effective treatment in refractory schizophrenia. Therapeutic drug monitoring together with early pharmacogenetic testing may offer a path for some patients with refractory psychotic symptoms unresponsive to clozapine treatment.

Effect of age on the relative efficacy of clozapine in schizophrenia

OBJECTIVE

Early treatment of schizophrenia improves outcomes. Clozapine appears to have unique benefit when other antipsychotic medication has failed. This systematic review and meta-analysis aims to assess clozapine's superiority over alternative antipsychotic medication and examine whether earlier use is associated with additional benefit.

METHOD

Systematic retrieval of blinded, randomized controlled trials comparing clozapine with alternative antipsychotics in adults with schizophrenia. The effect of mean age on relative clozapine response was examined using random effects meta-regression, and multiple linear regression on available patient data.

RESULTS

A total of 276 studies were retrieved. Thirty-four studies were included in the meta-analysis. Clozapine was significantly more effective than alternative antipsychotics in reducing psychotic symptoms and increasing response. However, meta-regression failed to show a more significant effect in younger patients (age on effect size (total psychotic symptoms) 0.00, P = 0.79 CI -0.03 to 0.03). Individual patient data were available for two studies, the larger of which showed a significant interaction between younger age and superiority of clozapine.

CONCLUSION

The results support clozapine's superiority over other antipsychotics. A convincing effect of age on this effect was not demonstrated, although this was suggested in one study. In view of the age of many of the included studies, and changes in reporting practice over time, new clozapine RCTs, which include age of illness onset as well as age at trial time, would be welcome in order to provide meta-analysable data for future use.

Moderators and mediators of antipsychotic response in delusional disorder: Further steps are needed

Delusional disorder (DD) has been traditionally considered a relatively rare and treatment-resistant psychotic disorder. In the last decade, increasing attention has focused on therapeutic outcomes of individuals affected by this disorder. The aim of this paper is to provide a synthesis of the literature addressing two very important questions arising from DD research: (1) For which patients with DD do antipsychotic medications work best (the moderators of response); and (2) What variables best explain the relationship between such treatments and their effectiveness (the mediators of response). We searched PubMed and Google Scholar databases for English, German, French and Spanish language papers published since 2000. We also included a few classic earlier papers addressing this topic. Variables potentially moderating antipsychotic response in DD are gender, reproductive status, age, duration of illness, the presence of comorbidity (especially psychiatric comorbidity) and its treatment, brain structure, and genetics of neurochemical receptors and drug metabolizing enzymes. Antipsychotic and hormonal blood levels during treatment, as well as functional brain changes, are potential mediating variables. Some, but not all, patients with DD benefit from antipsychotic treatment. Understanding the circumstances under which treatment works best can serve to guide optimal management.

Clozapine response trajectories and predictors of non-response in treatment-resistant schizophrenia: a chart review study

Although clozapine is the main antipsychotic medication for treatment-resistant schizophrenia, 40-70% of patients on clozapine have persistent psychotic symptoms (i.e. ultra-treatment-resistant schizophrenia, UTRS). We aimed to examine clozapine response/non-response patterns in patients with treatment-resistant schizophrenia, as well as determine patient clinico-demographic factors associated with long-term clozapine non-response. Clinico-demographic characteristics of 241 patients on clozapine were collected through a retrospective chart review. The median (interquartile range, IQR) follow-up from illness onset was 25.0 (IQR = 24.0) years. Clozapine response was assessed at median 10.8 (IQR = 14.0) months (Time 1, T1) and 7.2 (IQR = 13.5) years (Time 2, T2) after its initiation. It was evaluated by chart reviewers based on the information provided in clinical notes. Binomial logistic regression was used to determine clinico-demographic factors associated with clozapine non-response at both T1 and T2 (i.e. stable UTRS, S-UTRS) compared to clozapine response at both times (i.e. stable clozapine responders, S-ClozResp). Among clozapine responders (n = 122) at T1, 83.6% remained clozapine responsive and 16.4% became non-responsive at T2. In the UTRS group (n = 119) at T1, 87.4% remained clozapine non-responsive and 12.6% became responsive at T2. Duration of delay in clozapine initiation (OR = 0.94, Wald χ² = 5.33, p = 0.021) and number of pre-clozapine hospitalizations (OR = 0.95, Wald χ² = 5.20, p = 0.023) were associated with S-UTRS. Most UTRS patients were non-responsive to clozapine from the start of treatment. Preventing delay in initiating clozapine and relapses could help promote long-term clozapine response in patients with treatment-resistant schizophrenia. Future longitudinal studies are required to explore the neuropathological correlates of relapses and delay in clozapine initiation.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

INTRODUCTION

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

OBJECTIVE

This systematic review aims to identify barriers and facilitators to health data harmonization-including data sharing and linkage-by a comparative analysis of studies from Denmark and Switzerland.

METHODS

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

RESULTS

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

CONCLUSION

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

A systematic review of sex-based differences in effectiveness and adverse effects of clozapine

Clozapine is one of the most widely used antipsychotics for treating psychiatric illnesses such as schizophrenia and bipolar disorder. This drug, however, is associated with adverse effects such as weight gain, metabolic syndrome, and blood dyscrasias. The manifestations of mental illness may differ between men and women. Yet, there is little evidence on the influence of sex on treatment response or the occurrence of AEs. To fill this gap of knowledge, we carried out a systematic review of the literature on sex differences in the effectiveness and adverse effects of clozapine. Scant evidence has been published on differences in effectiveness of clozapine between men and women. Indeed, to the best of our knowledge, this issue has only been addressed in a published study. Regarding adverse effects, males have been reported to be more likely to develop metabolic abnormalities such as cholesterol or triglycerides, hypertension, and cardiovascular risk, while females are at a higher risk for gaining weight, developing diabetes, and needing laxatives. Nevertheless, given the scarcity of sex-based studies on this drug, further studies are needed to explore sex-based differences, as the results obtained may be crucial to clinical practice and help improve the quality of life of patients.

Delays and barriers to the commencement of clozapine in eligible people with a psychotic disorder: A literature review

AIM

While the majority of individuals with a first episode of psychosis (FEP) achieve symptomatic remission with the appropriate treatment, there is a small but significant proportion who do not achieve remission of symptoms despite adequate treatment with at least two antipsychotic medications (termed treatment resistance). Clozapine is indicated in individuals who fulfil the criteria for treatment-resistant schizophrenia, however, despite it being the most effective antipsychotic medication, there can be delays in the commencement of clozapine in eligible patients.

METHODS

A systematic search was performed to identify articles reporting either the time taken to commence clozapine (or delays) in eligible individuals or articles reporting barriers to the commencement of clozapine. The initial search generated 5588 articles and of these, 18 were eligible.

RESULTS

13 studies described delays in commencing clozapine and five studies reported on the barriers to the commencement of clozapine. The duration of delay from when an individual was deemed eligible for clozapine treatment to the time of clozapine commencement ranged from 19.3 weeks to 5.5 years. In addition, the duration of illness prior to clozapine initiation ranged from 1.1 to 9.7 years. It was found that some clinicians were more inclined to prescribe antipsychotic polypharmacy or doses higher than recommended than to prescribe clozapine.

CONCLUSIONS

Delays in commencing clozapine have been consistently demonstrated. Early intervention for psychosis services are the ideal settings to identify individuals with persistent positive psychotic symptoms and commence clozapine if indicated.

Predicting Unsuccessful Clozapine Treatment After First Use in Adult Patients With Psychotic Disorders

PURPOSE/BACKGROUND

Cessation of clozapine therapy and insufficient response may result in relapse of psychotic symptoms and in clinical admissions. However, discontinuation rates are high. Identifying patients at risk for unsuccessful clozapine use might enable clinicians to direct specific attention to them.

METHODS/PROCEDURES

Routinely collected data from a large insurance company were used to develop a simple prediction model for unsuccessful clozapine treatment in psychiatric patients 1 year after clozapine was first dispensed by a community pharmacy in the Netherlands. Multivariate logistic regression analyses were performed with the Nagelkerke R statistic as a measure of the predictive value of the model.

FINDINGS/RESULTS

A total of 937 patients were dispensed clozapine for the first time by their community pharmacy between January 1, 2011, and December 31, 2015 (index date). Of these, 741 patients had started their clozapine treatment in hospital before the index date (inpatient starters); the remaining 196 patients started clozapine as outpatients on the index date (outpatient starters). In 191 patients (20.4%), clozapine treatment was unsuccessful 1 year after the index date. Unsuccessful treatment was more common among outpatient starters than among inpatient starters (32.1% vs 17.3%). Using backward selection of the variables, a model consisting of 61 variables had the best predictive value overall (Nagelkerke R = 0.301), whereas a model consisting of 52 variables had the best predictive value in outpatient starters (Nagelkerke R = 0.676).

IMPLICATIONS/CONCLUSIONS

The likelihood of unsuccessful clozapine treatment after 1 year was higher among patients who started clozapine as outpatients. Despite the use of a diversity of variables and different statistical approaches, it was not possible to make a simple prediction model for unsuccessful clozapine treatment using relatively easily accessible data.

Real-World Effectiveness of Clozapine for Borderline Personality Disorder: Results From a 2-Year Mirror-Image Study

While some second-generation antipsychotics have shown efficacy on patients with borderline personality disorder (BPD), limited data exist regarding the effect of clozapine. Thus, we aimed to investigate the effects of clozapine on naturalistic outcomes in BPD patients with a 2-year mirror-image model. Among 25,916 patients with BPD, 1,107 redeemed ≥ 1 clozapine prescription. Of these, 18,188 were "specific" BPD patients, and 102 redeemed ≥ 1 clozapine prescription. During a mean observation period of 598.51 days, in all BPD patients, clozapine was associated with a significant reduction in psychiatric admissions from 2.52 (95% CI [2.31, 2.78]) to 2.00 (95% CI [1.77, 2.23]) admissions (p < .001) and a significant reduction in psychiatric bed-days from 190.08 (95% CI [176.84, 203.33]) to 65.95 (95% CI [58.27, 73.66]) bed-days (p < .001). Similar findings were found for "specific" BPD patients. The number of patients with intentional self-harm or overdose decreased significantly from 189 to 114 individuals (p < .001) after clozapine initiation. Randomized trials evaluating the risk- benefit ratio of clozapine in patients with severe BPD are warranted.

Treatment resistant schizophrenia - review and a call to action

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

Evaluation of a few discrete clinical markers may predict categorization of actively symptomatic non-acute schizophrenia patients as treatment resistant or responders: A study by ROC curve analysis and multivariate analyses

Here, we used Receiver Operating Characteristic (ROC) curve analysis to determine whether clinical factors may aid predicting the categorization of schizophrenia patients as Treatment Resistant (TRS) or antipsychotic responsive schizophrenia (ARS). Patients with an established condition of TRS or ARS were assessed for: clinical presentation and course; neurological soft signs (NES); psychopathology by PANSS; cognitive performances; quality of life scale (QLS); functional capacity; social functioning (PSP and SLOF scales). In ROC curve analysis, significance indicated that the Area under curve (AUC) allowed distinguishing between TRS and ARS. Multivariate analyses were additionally used to provide independent predictive analysis. Multiple clinical variables showed significant AUCs. The largest significant AUCs were found for: NES total score; SLOF Area2; QLS subscale; antipsychotic doses. The highest sensitivity was found for NES total score, the highest specificity for previous hospitalizations. The highest Odds Ratio of being included within the TRS category were found for: NES total score (7.5); QLS total score (5.49); and previous hospitalizations (4.76). This same circumscribed group of variables was also found to be predictive of TRS when adopting stepwise logistic regression or discriminant analysis. We concluded that the evaluation of few clinical factors may provide reliable and accurate predictions on whether one schizophrenia patient may be categorized as a TRS.

Potentially fatal outcomes associated with clozapine

Clozapine has been shown to be the most efficacious therapy for treatment resistant schizophrenia, estimated at one third of all schizophrenia cases. There is significant morbidity and mortality associated with clozapine including risk of agranulocytosis, aspiration pneumonia, bowel ischemia, myocarditis, seizures, and weight gain. Here we present a case of a 62-year-old man with chronic paranoid schizophrenia refractory to numerous antipsychotics who was started on clozapine therapy during an acute inpatient psychiatric admission. Within three weeks of starting clozapine, the patient developed flu-like symptoms, pleuritic chest pain, and was sent to a medical hospital for evaluation. After transfer, the patient had a rapidly deteriorating course with newly developed congestive heart failure, acute respiratory failure requiring intubation, and cardiovascular collapse requiring vasopressors. The patient expired within two days of transfer and four days after initial symptoms developed. The underlying etiology in this case is likely clozapine induced myocarditis leading to rapid cardiovascular collapse and death. Mortality with clozapine induced myocarditis has been estimated up to 24%. Given that 90% of clozapine cardiotoxic sequelae are seen in the first month post-initiation, more rigorous post-initiation surveillance is recommended for the first four weeks of clozapine with weekly cardiac enzymes (troponins, creatinine kinase-MB), EKG, and acute inflammatory markers (C-reactive protein, and erythrocyte sedimentation rate).

Long-term follow-up of clozapine prescribing

OBJECTIVE

Clozapine is uniquely effective for treatment-resistant schizophrenia, and so treatment continuation is essential. We aimed to identify factors associated with an increased likelihood of clozapine discontinuation in a cohort of patients in South East London.

METHODS

We gathered demographic and treatment information such as duration of illness and antipsychotic treatment history. t-tests, chi-square tests and binary logistic regression were used to compare patients who continued and discontinued clozapine during the study and to identify predictor variables for discontinuation.

RESULTS

Out of the study population of 133 patients, 48 discontinued clozapine at least once during the study period. The majority of these (75%) stopped treatment within the first 4 years of clozapine therapy. Age, ethnicity, diagnosis and antipsychotic treatment history were not predictive of the risk of clozapine discontinuation. However, male patients were more likely to stop taking clozapine (χ² = 6.81, p = 0.009). The odds of discontinuing clozapine were 2.15 times higher for male patients. The most common reason for discontinuation was patient refusal of treatment.

CONCLUSION

We found that patients who discontinue clozapine are more likely to be male, but no other demographic variable was found to predict treatment cessation. Discontinuation usually occurred due to patient refusal of treatment.

The Group of Treatment Resistant Schizophrenias. Heterogeneity in Treatment Resistant Schizophrenia (TRS)

Schizophrenia is composed of a heterogeneous group of patient segments. Our current notion of the heterogeneity in schizophrenia is based on patients presenting with diverse disease symptom phenotypes, risk factors, structural and functional neuropathology, and a mixed range of expressed response to treatment. It is important for clinicians to recognize the various clinical presentations of resistance to treatment in schizophrenia and to understand how heterogeneity across treatment resistant patient segments may potentially inform new strategies for the development of effective treatments for Treatment Resistant Schizophrenia (TRS). The heterogeneity of schizophrenia may be reduced by parsing patient segments based on whether patients demonstrate an adequate or inadequate response to treatment. In our current concept of TRS, TRS is defined as non-response to at least two adequate trials of antipsychotic medication and is estimated to affect about 30% of all patients with schizophrenia. In this narrative review, the author discusses that the demonstration of inadequate response to antipsychotic drugs (APDs) may infer that some TRS patients may be suffering from a non-dopamine pathophysiology since D2 receptor antagonist-based treatment is ineffective. Preliminary neurobiological findings may further support the pathophysiologic distinction of TRS from that of general schizophrenia. Investigation of the basis for heterogeneity in TRS through the systematic investigation of relevant "clusters" of similarly at risk individuals may hopefully bring us closer to realize a precision medicine approach for developing effective therapies for TRS patient segments.

Genetics of Schizophrenia: Ready to Translate?

PURPOSE OF REVIEW

This is an era where we have significantly advanced the understanding of the genetic architecture of schizophrenia. In this review, we consider how this knowledge may translate into advances that will improve patient care.

RECENT FINDINGS

Large-scale genome-wide association studies (GWAS) have identified more than a hundred loci each making a small contribution to illness risk. Meta-analysis of copy number variants (CNVs) in the Psychiatric Genomics Consortium (PGC) dataset has confirmed that some variants have a moderate or large impact on risk, although these are rare in the population. Genome sequencing advances allow a much more comprehensive evaluation of genomic variation. We describe the key findings from whole exome studies to date. These studies are happening against a backdrop of growing understanding of the regulation and expression of genes and better functional tools to investigate molecular mechanisms in model systems. We provide an overview of how recent approaches in schizophrenia genetics are converging and consider how they could impact on diagnostics, the development of personalized medicine, and drug discovery.

Efficacy of 42 Pharmacologic Cotreatment Strategies Added to Antipsychotic Monotherapy in Schizophrenia: Systematic Overview and Quality Appraisal of the Meta-analytic Evidence

IMPORTANCE

Limited treatment responses in schizophrenia prompted the testing of combining an antipsychotic drug treatment with a second psychotropic medication. A comprehensive evaluation of the efficacy of multiple medication combinations is missing.

OBJECTIVE

To summarize and compare the meta-analytically determined efficacy of pharmacologic combination strategies of antipsychotic drugs in adults with schizophrenia.

DATA SOURCES

Systematic search of PubMed and PsycInfo until May 13, 2016.

STUDY SELECTION

Meta-analyses of randomized clinical trials comparing the efficacy of antipsychotic drugs combined with other antipsychotic or nonantipsychotic medications vs placebos or antipsychotic monotherapy among adults with schizophrenia.

DATA EXTRACTION AND SYNTHESIS

Independent reviewers extracted the data and assessed the quality of the methods of the included meta-analyses using A Measurement Tool to Assess Systematic Reviews (AMSTAR), adding 6 new items to rate their quality. Effect sizes, expressed as standardized mean difference /Hedges g or risk ratio, were compared separately for combinations with any antipsychotic drug and for combinations with clozapine.

MAIN OUTCOMES AND MEASURES

The primary outcome was total symptom reduction. Secondary outcomes included positive and negative symptoms, treatment recommendations by authors, study-defined inefficacies, cognitive and depressive symptoms, discontinuation of treatment because of any cause, and inefficacies or intolerabilities.

RESULTS

Of 3397 publications, 29 meta-analyses testing 42 combination strategies in 381 individual trials and among 19 833 participants were included. For total symptom reductions, 32 strategies that augmented any antipsychotic drug and 5 strategies that augmented clozapine were examined. Fourteen combination treatments outperformed controls (standard mean difference/Hedges g, -1.27 [95% CI, -2.35 to -0.19] to -0.23 [95% CI, -0.44 to -0.02]; P = .05). No combination strategies with clozapine outperformed controls. The quality of the methods of the meta-analyses was generally high (mean score, 9 of a maximum score of 11) but the quality of the meta-analyzed studies was low (mean score, 2.8 of a maximum score of 8). Treatment recommendations correlated with the effect size (correlation coefficient, 0.22; 95% CI, 0.35-0.10; P < .001), yet effect sizes were inversely correlated with study quality (correlation coefficient, -0.06; 95% CI, 0.01 to -0.12; P = .02).

CONCLUSIONS AND RELEVANCE

Meta-analyses of 21 interventions fully or partially recommended their use, with recommendations being positively correlated with the effect sizes of the pooled intervention. However, the effect sizes were inversely correlated with meta-analyzed study quality, reducing confidence in these recommendations. Higher-quality trials and patient-based meta-analyses are needed to determine whether subpopulations might benefit from combination treatment, as no single strategy can be recommended for patients with schizophrenia based on the current meta-analytic literature.

Predictors of Nonhospitalization and Functional Response in Clozapine Treatment: A Nationwide, Population-Based Cohort Study

BACKGROUND

Clozapine remains the only evidence-based treatment for treatment-resistant schizophrenia, and prediction of clozapine response is important in developing stratified treatment. We studied potential predictors of clozapine response, applying functional assessments as well as service use.

PROCEDURES

We performed a nationwide cohort study among all individuals diagnosed with schizophrenia in Denmark after 1995 (age, ≥18 years) who initiated clozapine treatment between 2004 and 2011 with a Global Assessment of Functioning (GAF-F) score registered at clozapine initiation. During up to 2-year follow-up, clinical response was defined as (a) no further hospitalization with schizophrenia or (b) improvement in GAF-F score (moderate improvement: increase, ≥10; substantial improvement: increase, ≥20; and GAF-F, ≥50). We performed Cox regression analysis and report adjusted hazard rate ratios (HRRs; 95% confidence intervals [95% CIs]).

RESULTS

Among 502 clozapine users with a registered GAF-F score, 232 (46.2%) remained out of hospital, 96 (19.1%) achieved moderate functional improvement, and 29 (5.8%) substantial functional improvement. Of all potential predictors, voluntary status at clozapine initiation showed borderline statistical significance with nonhospitalization (HRR, 1.61; 95% CI, 0.97-2.67). Regarding functional improvement, living with a partner was the strongest predictor with an almost threefold increased HRR (2.78; 95% CI, 1.07-7.23). Female sex was only nonsignificantly associated with functional improvement, whereas the chance of substantial improvement decreased by 15% (HRR, 0.85; 95% CI, 0.72-1.00) for each year delay in clozapine initiation among females.

CONCLUSIONS

Living with a partner was the strongest predictor of functioning after clozapine initiation in this study. Although potentially indicating better premorbid functioning, this finding stresses the need and importance of social support during the course of the treatment independent of clinical factors.

The critical treatment window of clozapine in treatment-resistant schizophrenia: Secondary analysis of an observational study

Previous studies have suggested that a delay in initiating clozapine is one of the predictors of outcomes in treatment-resistant schizophrenia (TRS). However, whether there is a critical treatment window of clozapine in TRS and the duration of that window remain unclear. We conducted a secondary analysis of a previously published observational study using a retrospective chart review of 105 patients with TRS who were treated with clozapine. We included 90 patients who remained on clozapine for at least 3 months. The delay in initiating clozapine was an independent contributor to symptomatic improvement based on treatment with clozapine by multiple linear regression analysis. A receiver operating characteristic curve analysis (area under the curve: 0.78) confirmed 2.8 years was the best predictive cut-off value of delay in initiating clozapine for responses in patients treated with clozapine (sensitivity: 0.66, specificity: 0.84). In patients with a delay in initiating clozapine of ≤2.8 years and a delay in initiating clozapine of >2.8 years, the response rates were 81.6% and 30.8% (risk ratio=2.65; 95% confidence interval, 1.80, 3.63), respectively. Clinicians should reduce the delay in initiating clozapine to less than 3 years to improve symptomatic outcomes in TRS and to prevent clozapine-resistant schizophrenia.

The impact of clozapine on hospital use: a systematic review and meta-analysis

OBJECTIVE

The objective of this study was to perform a systematic review and meta-analysis of studies reporting the impact of clozapine on hospital use in people with a psychotic illness.

METHOD

PubMed, EMBASE, PsycINFO and the Cochrane Schizophrenia Group Trials Register were systematically searched from inception to 12 October 2016. We included all trials and observational studies, except case reports.

RESULTS

Thirty-seven studies were included. Clozapine significantly reduced the proportion of people hospitalised compared to control medicines (RR = 0.74; 95% CI: 0.69-0.80, P < 0.001, 22 studies, n = 44 718). There were significantly fewer bed days after clozapine treatment compared to before clozapine treatment in both controlled (MD = -34.41 days; 95% CI: -68.22 to -0.60 days, P = 0.046, n = 162) and uncontrolled studies (MD = -52.86 days; 95% CI: -79.86 days to -25.86 days, P < 0.001, n = 2917). Clozapine and control medicines had a similar time to rehospitalisation (-19.90 days; 95% CI: -62.42 to 22.63 days, P = 0.36).

CONCLUSION

Clozapine treatment reduced the number of people hospitalised and the number of bed days after treatment compared with before treatment. Clozapine has the potential to reduce acute hospital use among people with treatment refractory schizophrenia.

Pharmacological guidelines for schizophrenia: a systematic review and comparison of recommendations for the first episode

OBJECTIVES

Clinical practice guidelines (CPGs) support the translation of research evidence into clinical practice. Key health questions in CPGs ensure that recommendations will be applicable to the clinical context in which the guideline is used. The objectives of this study were to identify CPGs for the pharmacological treatment of first-episode schizophrenia; assess the quality of these guidelines using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument; and compare recommendations in relation to the key health questions that are relevant to the pharmacological treatment of first-episode schizophrenia.

METHODS

A multidisciplinary group identified key health questions that are relevant to the pharmacological treatment of first-episode schizophrenia. The MEDLINE and EMBASE databases, websites of professional organisations and international guideline repositories, were searched for CPGs that met the inclusion criteria. The AGREE II instrument was applied by three raters and data were extracted from the guidelines in relation to the key health questions.

RESULTS

In total, 3299 records were screened. 10 guidelines met the inclusion criteria. 3 guidelines scored well across all domains. Recommendations varied in specificity. Side effect concerns, rather than comparative efficacy benefits, were a key consideration in antipsychotic choice. Antipsychotic medication is recommended for maintenance of remission following a first episode of schizophrenia but there is a paucity of evidence to guide duration of treatment. Clozapine is universally regarded as the medication of choice for treatment resistance. There is less evidence to guide care for those who do not respond to clozapine.

CONCLUSIONS

An individual's experience of using antipsychotic medication for the initial treatment of first-episode schizophrenia may have implications for future engagement, adherence and outcome. While guidelines of good quality exist to assist in medicines optimisation, the evidence base required to answer key health questions relevant to the pharmacological treatment of first-episode schizophrenia is limited.

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

Up to 30% of people with schizophrenia do not respond to two (or more) trials of dopaminergic antipsychotics. They are said to have treatment-resistant schizophrenia (TRS). Clozapine is still the only effective treatment for TRS, although it is underused in clinical practice. Initial use is delayed, it can be hard for patients to tolerate, and clinicians can be uncertain as to when to use it. What if, at the start of treatment, we could identify those patients likely to respond to clozapine - and those likely to suffer adverse effects? It is likely that clinicians would feel less inhibited about using it, allowing clozapine to be used earlier and more appropriately. Genetic testing holds out the tantalizing possibility of being able to do just this, and hence the vital importance of pharmacogenomic studies. These can potentially identify genetic markers for both tolerance of and vulnerability to clozapine. We aim to summarize progress so far, possible clinical applications, limitations to the evidence, and problems in applying these findings to the management of TRS. Pharmacogenomic studies of clozapine response and tolerability have produced conflicting results. These are due, at least in part, to significant differences in the patient groups studied. The use of clinical pharmacogenomic testing - to personalize clozapine treatment and identify patients at high risk of treatment failure or of adverse events - has moved closer over the last 20 years. However, to develop such testing that could be used clinically will require larger, multicenter, prospective studies.

Two distinct patterns of treatment resistance: clinical predictors of treatment resistance in first-episode schizophrenia spectrum psychoses

BACKGROUND

Clozapine remains the only evidence-based antipsychotic for treatment-resistant schizophrenia (TRS). The ability to predict which patients with their first onset of schizophrenia would subsequently meet criteria for treatment resistance (TR) could help to diminish the severe functional disability which may ensue if TR is not recognized and correctly treated.

METHOD

This is a 5-year longitudinal assessment of clinical outcomes in a cohort of 246 first-episode schizophrenia spectrum patients recruited as part of the NIHR Genetics and Psychosis (GAP) study conducted in South London from 2005 to 2010. We examined the relationship between baseline demographic and clinical measures and the emergence of TR. TR status was determined from a review of electronic case records. We assessed for associations with early-, and late-onset TR, and non-TR, and differences between those TR patients treated with clozapine and those who were not.

RESULTS

Seventy per cent (n = 56) of TR patients, and 23% of the total study population (n = 246) were treatment resistant from illness onset. Those who met criteria for TR during the first 5 years of illness were more likely to have an early age of first contact for psychosis (<20 years) [odds ratio (OR) 2.49, 95% confidence interval (CI) 1.25-4.94] compared to those with non-TR. The relationship between an early age of first contact (<20 years) and TR was significant in patients of Black ethnicity (OR 3.71, 95% CI 1.44-9.56); and patients of male gender (OR 3.13 95% CI 1.35-7.23).

CONCLUSIONS

For the majority of the TR group, antipsychotic TR is present from illness onset, necessitating increased consideration for the earlier use of clozapine.

Correlates of Clozapine Use after a First Episode of Schizophrenia: Results From a Long-term Prospective Study

BACKGROUND

Earlier commencement of clozapine has been related to a better response in treatment-resistant schizophrenia.

OBJECTIVES

To identify variables that predict clozapine use after a first episode of schizophrenia (FES).

METHODS

Patients with FES and ≤15 days of lifetime antipsychotic treatment were followed up during naturalistic treatment, and the patients who were initiated on clozapine were compared with those receiving non-clozapine antipsychotics for ≥24 months regarding demographic and clinical baseline characteristics, adherence, and relapse patterns during follow-up. Treatment-resistant schizophrenia was defined as two or more antipsychotic trials of adequate dose for ≥6 weeks.

RESULTS

Twenty-eight patients who used clozapine and 77 non-clozapine antipsychotic users were included. Clozapine was initiated after a mean of 2.5 ± 1.1 adequate antipsychotic trials. Eight of the 28 clozapine-treated patients (28.6 %) began their clozapine treatment during the first 12 months of follow-up (mean 7.1 ± 3.3 months) and their premorbid childhood adjustment was significantly worse than those who started clozapine later (mean 78.5 ± 43.0 months). Compared with non-clozapine users, patients who started clozapine had significantly more relapses in the first 6 months of follow-up prior to clozapine use (35.7 vs. 11.7 %, p = 0.005), and were significantly more likely to have a first relapse despite treatment adherence (38.1 vs. 73.3 %, p = 0.01). In the multivariate analyses, antipsychotic polypharmacy and first relapse despite adherence to antipsychotic treatment independently predicted subsequent clozapine use.

CONCLUSIONS

Clozapine use after a FES was predicted by a first relapse while being adherent to non-clozapine antipsychotics, especially if the first relapse occurred within the first 6 months. Developmental childhood difficulties predicted significantly earlier clozapine use.