Treatment with psychostimulants and atomoxetine in people with psychotic disorders: reassessing the risk of clinical deterioration in a real-world setting.

BACKGROUND: Although attention-deficit hyperactivity disorder (ADHD) is often comorbid with schizophrenia spectrum and other psychotic disorders (SZSPD), concerns about an increased risk of psychotic events have limited its treatment with either psychostimulants or atomoxetine. AIMS: To examine whether the risk of hospital admission for psychosis in people with SZSPD was increased during the year following the introduction of such medications compared with the year before. METHOD: This was a retrospective cohort study using Quebec (Canada) administrative health registries, including all Quebec residents with a public prescription drug insurance plan and a diagnosis of psychotic disorder, defined by relevant ICD-9 or ICD-10 codes, who initiated either methylphenidate, amphetamines or atomoxetine, between January 2010 and December 2016, in combination with antipsychotic medication. The primary outcome was time to hospital admission for psychosis within 1 year of initiation. State sequence analysis was also used to visualise admission trajectories for psychosis in the year following initiation of these medications, compared with the previous year. RESULTS: Out of 2219 individuals, 1589 (71.6%) initiated methylphenidate, 339 (15.3%) amphetamines and 291 (13.1%) atomoxetine during the study period. After adjustment, the risk of hospital admission for psychosis was decreased during the 12 months following the introduction of these medications when used in combination with antipsychotics (adjusted HR = 0.36, 95% CI 0.24-0.54; P < 0.0001). CONCLUSIONS: These findings suggest that, in a real-world setting, when used concurrently with antipsychotic medication, methylphenidate, amphetamines and atomoxetine may be safer than generally believed in individuals with psychotic disorders.

Problem gambling in psychotic disorders: A systematic review and meta-analysis of prevalence.

INTRODUCTION: Problem gambling (PBG) is more common in people with mental health disorders, including substance use, bipolar, and personality disorders, than in the general population. Although individuals with psychotic disorders might be expected to be more vulnerable to PBG, fewer studies have focused on this comorbidity. The aim of this review was to estimate the prevalence of PBG in people with psychotic disorders. METHODS: Medline (Ovid), EMBASE, PsycINFO (Ovid), CINAHL, CENTRAL, Web of science, and ProQuest were searched on November 1, 2023, without language restrictions. Observational and experimental studies including individuals with psychotic disorders and reporting the prevalence of PBG were included. Risk of bias was assessed using the Joanna Briggs Institute critical appraisal for systematic reviews of prevalence data. The pooled prevalence of PBG was calculated using a fixed effects generalized linear mixed model and presented through forest plots. RESULTS: Of 1271 records screened, 12 studies (n = 3443) were included. The overall prevalence of PBG was 8.7% (95% CI = 7.8%-9.7%, I2 = 69%). A lower prevalence was found in studies with a low risk of bias (5.6%; 95% CI = 4.4%-7.0%) compared with studies with a moderate risk of bias (10.4%; 95% CI = 9.2%-11.7%). Different methods used to assess PBG also contributed to the heterogeneity found. CONCLUSION: This meta-analysis found substantial heterogeneity, partly due to the risk of bias of the included studies and a lack of uniformity in PBG assessment. Although more research is needed to identify those at increased risk for PBG, its relatively high prevalence warrants routine screening for gambling in clinical practice.

Problem gambling among people with first-episode psychosis: protocol for a prospective multicenter cohort study.

BACKGROUND: The limited available data suggest that the prevalence of problem gambling is increased among young adults with first-episode psychosis, possibly due in part to several risk factors for problem gambling that are common in this population. Aripiprazole, a widely used antipsychotic drug, has also been linked to cases of problem gambling, but causality remains uncertain. Although the consequences of problem gambling further hinder the recovery of people with first-episode psychosis, there is a paucity of research about this comorbidity and its risk factors. Additionally, to our knowledge, no screening instrument for problem gambling tailored to these individuals exists, contributing to its under-recognition. Further, treatment approaches for problem gambling adapted to this population are at an embryonic stage, while existing treatments effectiveness remains to be documented. Using an innovative screening and assessment procedure for problem gambling, this study aims to identify risk factors for problem gambling among people with first-episode psychosis and to document the effectiveness of standard treatment approaches. METHODS: This is a multicenter prospective cohort study conducted in two first-episode psychosis clinics, including all patients admitted between November 1st, 2019, and November 1st, 2023, followed for up to 3 years until May 1st, 2024. These 2 clinics admit approximately 200 patients annually, for an expected sample size of 800 individuals. The primary outcome is the occurrence of a DSM-5 diagnosis of gambling disorder. All patients are screened and evaluated for problem gambling using a systematic procedure at admission, and every 6 months thereafter. Socio-demographic and clinical variables are prospectively extracted from the patients' medical records. The nature and effectiveness of treatments for problem gambling offered to affected individuals are also documented from medical records. Survival analyses with Cox regression models will be used to identify potential risk factors for problem gambling. Descriptive statistics will document the effectiveness of treatments for problem gambling in this population. DISCUSSION: A better understanding of potential risk factors for problem gambling among people with first-episode psychosis will allow for better prevention and detection of this neglected comorbidity. Results of this study will also hopefully raise clinicians' and researchers' awareness and serve as the basis to adapted treatments that will better support recovery. TRIAL REGISTRATION: ClinicalTrials.gov, NCT05686772. Retrospectively registered, 9 January 2023.

Gaming Disorder and Psychotic Disorders: A Scoping Review.

BACKGROUND: There is a growing interest in understanding the impact of video games in the clinical field, given that their excessive use could be associated with health issues. Particularly, gaming disorder (GD) is considered as an addictive behavioral disorder. Clinicians widely recognize the comorbidity of gaming and psychotic disorders (PDs). Furthermore, association between addictive (i.e., substance use disorders) and PDs are well recognized by clinicians. It seems of high interest to explore GD among people with PDs. To this day, little is known about the consequences of GD in vulnerable populations. OBJECTIVES: The aim of this scoping review was to summarize the available research on the comorbidity between GD and PD and to identify the knowledge gaps in this field. METHODS: We used Levac's six-stage methodology for scoping review. Two-hundred and forty-two articles from seven databases were identified. Eight articles respected our inclusion and exclusion criteria. RESULTS: No available study has assessed the prevalence or incidence of GD among patients with PDs. The cases reported highlight the possibility that excessive video gameplay or abrupt gaming disruption could trigger psychosis in some patients. CONCLUSION: The results highlight a significant lack of knowledge concerning PDs associated with GD as only a few reported cases and one empirical study exposed the potential association between those conditions.

Association between previous and future antipsychotic adherence in patients initiating clozapine: real-world observational study.

BACKGROUND: Although recognised as the most effective antipsychotic for treatment-resistant schizophrenia, clozapine remains underused. One reason is the widespread concern about non-adherence to clozapine because of poor adherence before initiating clozapine. AIMS: To determine if prior poor out-patient adherence to treatmentbefore initiating clozapine predisposes to poor out-patient adherence to clozapine or to any antipsychotics (including clozapine) after its initiation. METHOD: This cohort study included 3228 patients with schizophrenia living in Quebec (Canada) initiating (with a 2-year clearance period) oral clozapine (index date) between 2009 and 2016. Using pharmacy data, out-patient adherence to treatment was measured by the medication possession ratio (MPR), over a 1-year period preceding and following the index date. Five groups of patients were formed based on their prior MPR level (independent variable). Two dependent variables were defined after clozapine initiation (good out-patient adherence to any antipsychotics and to clozapine only). Along with multiple logistic regressions, state sequence analysis was used as a visual representation of antipsychotic-use trajectories over time, before and after clozapine initiation. RESULTS: Although prior poor adherence to antipsychotics was associated with poor adherence after clozapine initiation, the absolute risk of subsequent poor adherence remained low, regardless of previous adherence level. Most patients adhered to their treatment after initiating clozapine (>68% to clozapine and >84% to any antipsychotics). CONCLUSIONS: Despite the fact that poor adherence prior to initiating clozapine is widely recognised by clinicians as a barrier for the prescription of clozapine, the current study supports the initiation of clozapine in all eligible patients.

Clozapine Rechallenge or Continuation Despite Neutropenia, an Extended Follow-up of a Consecutive Quebec Case Series.

BACKGROUND: Clozapine is the most efficacious antipsychotic for treatment-resistant schizophrenia. However, clozapine-induced neutropenia may warrant treatment discontinuation, hindering recovery. Several case reports describe clozapine rechallenge or continuation despite neutropenia, although many are subject to selective reporting, with incomplete information and short follow-up periods. Thus, consecutive case series, devoid of such bias, with long-term comprehensive follow-up are needed to better assess this practice. This study aimed to describe consecutively the evolution of every patient in the Québec City catchment area for whom clozapine was either reintroduced after neutropenia during a previous clozapine trial or was maintained despite a first neutropenia. METHODS: Patients were identified through clozapine's national hematological monitoring database and their medical records between January 1, 2000, and October 22, 2017. RESULTS: Twenty-three patients were identified, 8 continued clozapine despite neutropenia, while 15 discontinued clozapine and attempted rechallenge; among the latter, 4 patients were successfully rechallenged after agranulocytosis without the use of granulocyte colony-stimulating factors, which is the largest published consecutively. A total of 6 patients experienced further neutropenia episodes. Every patient who had a neutropenia recurrence also had a possible explanation for neutropenia other than exposure to clozapine. After a median follow-up of 4.8 years, 16 patients were still on clozapine and 3 cases discontinued because of a hematological event. CONCLUSIONS: This study adds further data on the subject of clozapine rechallenge or continuation despite neutropenia. Clozapine rechallenge after agranulocytosis may be less perilous than first thought, but a systematic review on this specific subject is needed.

Antipsychotic utilization trajectories three years after initiating or reinitiating treatment of schizophrenia: A state sequence analysis approach.

OBJECTIVE: This study aims to describe the utilization patterns of antipsychotic (AP) medication in patients with schizophrenia (SCZ), three years after initiating or reinitiating a given AP. METHODS: Based on medico-administrative information on patients living in Quebec (Canada), this retrospective cohort study included 6444 patients with a previous diagnosis of SCZ initiating or reinitiating AP medication between January 1, 2012, and December 31, 2014, with continuous coverage by public drug insurance. For each day of follow-up (1092 days), patient was either exposed to one of the chosen categories of APs, or to none. This patient's sequence of AP exposure overtime has been referred to as the "antipsychotic utilization trajectory". These trajectories were analyzed using a State Sequence Analysis, an innovative approach which provides useful visual information on the continuation and discontinuation patterns of use over time. RESULTS: Clozapine and long-acting injectable second-generation APs had the best continuation and discontinuation patterns over 3 years among all other groups, including less switching of APs, while oral first-generation APs had the poorest patterns. These findings were comparable among incident and non-incident cohorts. Oral second-generation antipsychotics, excluding clozapine, had a poorer continuation and discontinuation pattern than long-acting injectable antipsychotics. CONCLUSION: State Sequence Analysis provides a clear representation of treatment adherence in comparison with dichotomous indicators of adherence or discontinuation. Consequently, this innovative method has shed light on the impact of the AP chosen to initiate or reinitiate treatment in SCZ, which has been identified as a key factor for long-term treatment continuation and discontinuation.

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.

Problem Gambling Associated With Aripiprazole in First-Episode Psychosis Patients: A Series of 6 Case Reports.

BACKGROUND: Aripiprazole (ARI), an antipsychotic drug used to treat various mental health disorders, has recently been associated with the emergence of problem gambling (PBG). However, few cases have been reported in the schizophrenia-related psychotic disorders population, and even fewer provided sufficient details to systematically assess the causality of the association. METHODS: This article describes 6 cases with first-episode psychosis in whom PBG emerged while on ARI. Detailed information was gathered from clinical staff and patients' families to systematically assess the causal link between ARI and the emergence of PBG using the Naranjo and Liverpool Adverse Drug Reaction scales. FINDINGS: Five of these cases were previously diagnosed with a substance use disorder and/or cluster B personality traits. Five had received a more potent dopaminergic antagonist treatment before being switched to ARI. Two of them had presented PBG before being diagnosed with a psychotic disorder. The level of certainty about the causal role of ARI varied from possible to certain, and in 4 cases, the 2 scales yielded different ratings. IMPLICATIONS: Although these cases suggest that ARI may be associated with the emergence of PBG in the early course of schizophrenia-related psychotic disorders, they cannot prove the causality or the strength of this association. They provide the impetus to perform adequately powered and well-controlled prospective studies to draw more definite conclusion about the causality of this association and, in the meantime, further emphasize the need to carefully assess PBG in this population.

Case Reports of Aripiprazole and Problematic Gambling in Schizophrenia: A Critical Review of the Evidence.

BACKGROUND: Pharmacovigilance studies have reported a higher risk of problematic gambling (PG) in people receiving aripiprazole (ARI), a partial dopamine agonist. This association needs to be specifically assessed in schizophrenia (SZ) given the high prevalence of risk factors for PG in this population (eg, comorbid substance use) and given the nature of the dopamine dysfunction in this disorder. At the present stage, case studies may shed light on such an association. METHODS: All published cases involving SZ patients with PG while on ARI were systematically identified. Two instruments were used to assess causality. RESULTS: We identified 16 published SZ cases exposed to ARI experiencing PG. Half of whom had a gambling history before ARI exposition. Naranjo scores led to the estimation of a possible link between ARI exposition and PG in 15 of 16 cases (average score of 3) and probable (score of 5) in 1 case. More than 50% of items were left unknown owing to the lack of information or scale limitations. Using the Liverpool algorithm, causality estimation was raised to probable in 13 of 16 cases, definite in 1 case, and nonassessable in 2 cases. CONCLUSIONS: The present review confirms that ARI may be involved in the occurrence of PG in some SZ patients. However, important information to assess causality was frequently missing, and the 2 scales used did not yield the same degree of certainty. The current article calls for including more details in future case reports and for well-powered studies carefully assessing factors such as comorbid diagnoses.

[Initiating an antipsychotic drug treatment for schizophrenia: the situation in Quebec, Canada, from 1998 to 2006]. / Amorcer un traitement antipsychotique en schizophrénie : la situation au Québec de 1998 à 2006.

Objectives To describe factors associated with the following characteristics of the first prescription of an antipsychotic drug treatment (ADT): 1) prescribing physician type (psychiatrist vs. general practitioner); 2) second-generation vs. first-generation antipsychotic drug; 3) in conjunction with at least one additional antipsychotic drug (multitherapy); 4) never renewed by the patient.Methods This is a pharmacoepidemiologic study using administrative data from the Régie de l'assurance maladie du Québec (RAMQ), the public healthcare insurer in Quebec, Canada. Available data sample was exhaustive for adults with a diagnosis of schizophrenia who received an ADT under RAMQ drug coverage from 1998 to 2006. We report multiple logistic regression results.Results Among 16,225 patients who met inclusion criteria 46.2% were women and 70% were beneficiaries of governmental financial assistance. Patients who had their ADT prescribed by psychiatrists tended to be younger and were more burdened by their mental illness. Multitherapy was associated with hospitalization with a psychotic disorder as main diagnosis, lower socioeconomic status, and age between 35 and 64. Second-generation antipsychotic use became progressively more prominent during the period under study. Antipsychotic non renewal was correlated with substance use disorders and was less likely to happen following hospitalization with a psychiatric main diagnosis. Conclusions Although this study is subject to the intrinsic limitations of secondary analysis of administrative data, the database available for study was exhaustive within the Quebec healthcare system and included data from both general practice and specialized care, which allowed us to draw a relevant picture of how ADT were initiated for schizophrenia in Quebec, Canada, from 1998 to 2006. This timeframe is especially relevant since the 1990s were marked by the introduction of second-generation antipsychotics in Canada.

Psychotic Disorders and exosomes: An overview of current evidence and future directions.

Due to its reliance on heterogeneous symptomatology, the accurate diagnosis of psychotic disorders remains a challenging task in clinical practice. Precise and early diagnosis of psychotic disorders facilitates early intervention, which has been shown to have substantial benefits for long-term outcomes. Still, the lack of specific biomarkers is an important limitation in early diagnosis and intervention. Exosomes, which act as messengers between cells, including brain cells, contain a vast array of molecules that hold promise for unveiling disorder-specific abnormalities. In this review, we discuss recent evidence highlighting the potential of circulating exosomes and brain-derived exosomes as valuable tools for the identification of accessible, non-invasive, and blood-based biomarkers of psychotic symptomatology and risk. We discuss current limitations in biomarker discovery studies focusing on exosomes. To enhance diagnosis specificity and treatment response, we also provide guidance for future investigations that need to target biomarkers of risk and relapse, as well as consider duration of untreated psychosis, biological sex, and other factors in the multifactorial biosignature of psychosis.

The effects of antipsychotic discontinuation or maintenance on the process of recovery in remitted first-episode psychosis patients - A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The optimal duration of antipsychotic treatment following remission of first-episode psychosis (FEP) is uncertain, considering potential adverse effects and individual variability in relapse rates. This study aimed to investigate the effect of antipsychotic discontinuation compared to continuation on recovery in remitted FEP patients. METHODS: CENTRAL, MEDLINE (Ovid), Embase, and PsycINFO databases were searched on November 2, 2023, with no language restrictions. RCTs evaluating antipsychotic discontinuation in remitted FEP patients were selected. The primary outcome was personal recovery, and secondary outcomes included functional recovery, global functioning, hospital admission, symptom severity, quality of life, side effects, and employment. Risk of bias was assessed using the Cochrane risk-of-bias tool 2, and the certainty of evidence was evaluated with GRADE. Meta-analysis used a random-effect model with an inverse-variance approach. RESULTS: Among 2185 screened studies, 8 RCTs (560 participants) were included. No RCTs reported personal recovery as an outcome. Two studies measured functional recovery, and discontinuation group patients were more likely to achieve functional recovery (RR 2.19; 95% CIs: 1.13, 4.22; I2 = 0%; n = 128), although evidence certainty was very low. No significant differences were found in hospital admission, symptom severity, quality of life, global functioning, or employment between the discontinuation and continuation groups. CONCLUSIONS: Personal recovery was not reported in any antipsychotic discontinuation trial in remitted FEP. The observed positive effect of discontinuation on functional recovery came from an early terminated trial and an RCT followed by an uncontrolled period. These findings should be interpreted cautiously due to very low certainty of evidence.

Speech markers to predict and prevent recurrent episodes of psychosis: A narrative overview and emerging opportunities.

Preventing relapse in schizophrenia improves long-term health outcomes. Repeated episodes of psychotic symptoms shape the trajectory of this illness and can be a detriment to functional recovery. Despite early intervention programs, high relapse rates persist, calling for alternative approaches in relapse prevention. Predicting imminent relapse at an individual level is critical for effective intervention. While clinical profiles are often used to foresee relapse, they lack the specificity and sensitivity needed for timely prediction. Here, we review the use of speech through Natural Language Processing (NLP) to predict a recurrent psychotic episode. Recent advancements in NLP of speech have shown the ability to detect linguistic markers related to thought disorder and other language disruptions within 2-4 weeks preceding a relapse. This approach has shown to be able to capture individual speech patterns, showing promise in its use as a prediction tool. We outline current developments in remote monitoring for psychotic relapses, discuss the challenges and limitations and present the speech-NLP based approach as an alternative to detect relapses with sufficient accuracy, construct validity and lead time to generate clinical actions towards prevention.

Prevalence of schizophrenia spectrum and other psychotic disorders in problem gambling: A systematic review and meta-analysis.

BACKGROUND: High rates of psychiatric comorbidities have been found in people with problem gambling (PBG), including substance use, anxiety, and mood disorders. Psychotic disorders have received less attention, although this comorbidity is expected to have a significant impact on the course, consequences, and treatment of PBG. This review aimed to estimate the prevalence of psychotic disorders in PBG. METHODS: Medline (Ovid), EMBASE, PsycINFO (Ovid), CINAHL, CENTRAL, Web of Science, and ProQuest were searched on November 1, 2023, without language restrictions. Studies involving people with PBG and reporting the prevalence of schizophrenia spectrum and other psychotic disorders were included. Risk of bias was assessed using the Joanna Briggs Institute critical appraisal checklist for systematic reviews of prevalence data. The pooled prevalence of psychotic disorders was calculated using a random effects generalized linear mixed model and presented with forest plots. RESULTS: Of 1,271 records screened, 22 studies (n = 19,131) were included. The overall prevalence of psychotic disorders was 4.9% (95% CI, 3.6-6.5%, I2 = 88%). A lower prevalence was found in surveyed/recruited populations, compared with treatment-seeking individuals and register-based studies. No differences were found for factors such as treatment setting (inpatient/outpatient), diagnoses of psychotic disorders (schizophrenia only/other psychotic disorders), and assessment time frame (current/lifetime). The majority of included studies had a moderate risk of bias. CONCLUSIONS: These findings highlight the relevance of screening problem gamblers for schizophrenia spectrum and other psychotic disorders, as well as any other comorbid mental health conditions, given the significant impact such comorbidities can have on the recovery process.

Sex-specific immune mechanisms in PTSD symptomatology and risk: A translational overview and perspectives.

Altered immune function in patients with posttraumatic stress disorder (PTSD) may play a role in the disorder pathophysiology and onset. Women are more likely to develop PTSD, suggesting potential sex-specific inflammatory mechanisms underlying the dichotomous prevalence and risk of PTSD in men and women. In this review we examine the available literature to better assess the state of knowledge in the field. In humans, increased systemic inflammation is found in both men and women with PTSD, but seems to be at a greater extend in women. Despite the existence of few clinical studies taking account of sex as a factor in the observed immune changes in PTSD, challenges in the study of sex-specific immune function in humans include: controlling for confounding variates such as the type of trauma and the ethnicity; and limited methodologies available to study central nervous system (CNS)-relevant changes. Thus, preclinical studies are a valuable tool to provide us with key insights on sex-specific peripheral and CNS immune mechanisms underlying PTSD. Available preclinical studies reported increased systemic and CNS inflammation, as well as elevated trafficking of monocytes from the periphery to the brain in both male and female rodents. To date, psychological trauma-induced inflammation is more robust in female vs male rodents. Limitations of preclinical studies include animal models hardly applicable to female rodents, and hormonal changes across estrus phases that may affect immune function. The present review: (1) highlights the key findings from both human and animal studies, (2) provides guidance to address limitations; and (3) discusses the gap of knowledge on the complex intertwined interaction between the brain, neurovascular, and systemic units.

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

OBJECTIVES: Rechallenge/continuation of clozapine in association with colony-stimulating factors (CSFs) following neutropenia/agranulocytosis has been reported, but many questions remain unanswered about efficacy and safety. This systematic review aims to assess the efficacy and safety of rechallenging/continuing clozapine in patients following neutropenia/agranulocytosis using CSFs. METHODS: MEDLINE, Embase, PsycInfo, and Web of Science databases were searched from inception date to July 31, 2022. Articles screening and data extraction were realized independently by two reviewers, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 systematic review guidance. Included articles had to report on at least one case where clozapine was rechallenged/continued using CSFs despite previous neutropenia/agranulocytosis. RESULTS: Eight hundred forty articles were retrieved; 34 articles met the inclusion criteria, totaling 59 individual cases. Clozapine was successfully rechallenged/continued in 76% of patients for an average follow-up period of 1.9 years. There was a trend toward better efficacy reported in case reports/series, compared with consecutive case series (overall success rates of 84% and 60%, respectively, p-value = 0.065). Two administration strategies were identified, "as-needed" and prophylactic, both yielding similar success rates (81% and 80%, respectively). Only mild and transient adverse events were documented. CONCLUSIONS: Although limited by the relatively small number of published cases, factors such as time of onset to first neutropenia and severity of the episode did not seem to impact the outcome of a subsequent clozapine rechallenge using CSFs. While the efficacy of this strategy remains to be further adequately evaluated in more rigorous study designs, its long-term innocuity warrants considering its use more proactively in the management of clozapine hematological adverse events as to maintain this treatment for as many individuals as possible.