Guidelines for the Pharmacotherapy of Schizophrenia in Adults

Associations between clozapine availability, the diagnosis of treatment-resistant schizophrenia subgroups, antipsychotic monotherapy, and concomitant psychotropics among patients with schizophrenia: a real-world nationwide study

BACKGROUND AND HYPOTHESIS

The rate of antipsychotic polypharmacy is high. One risk factor for antipsychotic polypharmacy may be the severity of schizophrenia, including treatment-resistant schizophrenia (TRS). We hypothesized that the institutions that are able to prescribe clozapine present differences in pharmacological treatment even before TRS is diagnosed.

STUDY DESIGN

A total of 8155 patients with schizophrenia were divided into the clozapine-available institution (CAI) group and the clozapine-unavailable institution (CUI) group. The psychotropic prescription rates at discharge were compared between the two groups. Furthermore, to investigate whether the diagnosis of TRS subgroups influenced treatment efficacy, we compared CAIs and CUIs with descriptions of subgroups with TRS (DSTRS) and those without descriptions of subgroups with TRS (NDSTRS).

RESULTS

Compared to the CUI group, the rates of both antipsychotic monotherapy (58.3% vs. 50.7%; P = 2.4 × 10-7) and antipsychotic monotherapy without the concomitant use of other psychotropics (20.4% vs. 15.6%; P = 3.8 × 10-5) were significantly higher in the CAI group. The rate of antipsychotic monotherapy in the CAI with DSTRS group (63.3%) was significantly higher than that in the CAI with NDSTRS group (54.5%; P = 1.4 × 10-12), the CUI with DSTRS group (49.6%; P = 4.9 × 10-9), and the CUI with NDSTRS group (50.9%; P = 2.0 × 10-8). The rate of antipsychotic monotherapy without the concomitant use of other psychotropics in the CAI with DSTRS group (22.6%) was also significantly higher than that in the CAI with NDSTRS group (18.7%; P = 4.7 × 10-4), the CUI with DSTRS group (15.9%; P = 5.5 × 10-4), and the CUI with NDSTRS group (15.2%; P = 8.0 × 10-5). There was no significant difference in these rates between the other groups.

CONCLUSIONS

Both the availability of clozapine prescriptions and the precise diagnosis of TRS subgroups at discharge can promote the development of an organizational culture that facilitates the treatment of patients with schizophrenia.

An Update on the Use of Neuromodulation Strategies in the Treatment of Schizophrenia

The field of neuromodulation has evolved tremendously and now includes a vast array of interventions utilizing different technologies that span electrical, magnetic, and ultrasound forms of stimulation. The evolution of interventions holds the promise of fewer adverse effects and a noninvasive approach, increasing the scale at which these interventions may be offered in hospital and community settings. While the majority of neuromodulation studies have focused on patients with mood disorders, predominantly depression, there is an unmet need for patients with schizophrenia, who are in dire need of novel therapeutic options. Advances in neuroimaging and approaches for examining individual variability and transdiagnostic symptoms may lead to more effective neuromodulation treatments in this patient population. This overview explores the modern landscape of invasive and noninvasive neuromodulation treatments for patients with schizophrenia. It begins with approaches that involve diffuse stimulation of the cortex and subcortex and then reviews more focal stimulation approaches at the cortical and subcortical levels. The authors also reflect on the relationship between our understanding of the neurobiology of schizophrenia and neuromodulation interventions.

Correlation Between Clozapine and CRP Levels in Relation to Smoking Status

AIMS

Both inflammation and smoking are known to affect clozapine metabolism. However, the impact of inflammation on clozapine metabolism in relation to smoking status is unclear. Therefore, we investigated correlations between C-reactive protein (CRP) and clozapine levels in smokers and non-smokers separately.

METHODS

Patients were included retrospectively from a therapeutic drug monitoring (TDM) service in Oslo, Norway, during January 2005-April 2022. Inclusion criteria were known smoking status and CRP measurements no longer than 7 days before or after clozapine TDM. Exclusion criteria were confirmed blood sampling for TDM outside 10-30 h after the last clozapine intake. Information about clozapine dosing was retrieved from the requisition forms.

RESULTS

In 126 patients fulfilling the criteria (47% smokers), dose-adjusted serum concentration (CD) of clozapine correlated significantly with CRP in non-smokers (R = 0.492; p < 001) but not in smokers (R = 0.191; p = 0.166). When subgrouping non-smoking patients into low CRP (< 5 mg/L; reference [51% of the population]), mid CRP (5-50 [37%]) and high CRP (> 50 [12%]), clozapine CD gradually increased in mid- (+48%, p = 0.004) and high-CRP groups (+204%, p < 0.001) compared with the low-CRP group. No significant differences in clozapine CD were found between CRP groups among smokers (p > 0.15).

CONCLUSIONS

We report a significant correlation between CD of clozapine and CRP levels in non-smoking patients only. In these patients, clozapine CD is more than 3-fold higher at CRP > 50 versus CRP < 5. This suggests that non-smokers are most susceptible to clozapine side effects during inflammation or infection and represent patients where TDM analyses are especially important for guiding clozapine dosing.

A New Era of Muscarinic Acetylcholine Receptor Modulators in Neurological Diseases, Cancer and Drug Abuse

The cholinergic pathways in the central nervous system (CNS) play a pivotal role in different cognitive functions of the brain, such as memory and learning. This review takes a dive into the pharmacological side of this important part of CNS function, taking into consideration muscarinic receptors and cholinesterase enzymes. Targeting a specific subtype of five primary muscarinic receptor subtypes (M1-M5) through agonism or antagonism may benefit patients; thus, there is a great pharmaceutical research interest. Inhibition of AChE and BChE, orthosteric or allosteric, or partial agonism of M1 mAChR are correlated with Alzheimer's disease (AD) symptoms improvement. Agonism or antagonism on different muscarinic receptor subunits may lessen schizophrenia symptoms (especially positive allosteric modulation of M4 mAChR). Selective antagonism of M4 mAChR is a promising treatment for Parkinson's disease and dystonia, and the adverse effects are limited compared to inhibition of all five mAChR. Additionally, selective M5 antagonism plays a role in drug independence behavior. M3 mAChR overexpression is associated with malignancies, and M3R antagonists seem to have a therapeutic potential in cancer, while M1R and M2R inhibition leads to reduction of neoangiogenesis. Depending on the type of cancer, agonism of mAChR may promote cancer cell proliferation (as M3R agonism does) or protection against further tumor development (M1R agonism). Thus, there is an intense need to discover new potent compounds with specific action on muscarinic receptor subtypes. Chemical structures, chemical modification of function groups aiming at action enhancement, reduction of adverse effects, and optimization of Drug Metabolism and Pharmacokinetics (DMPK) will be further discussed, as well as protein-ligand docking.

The association between benzodiazepine prescriptions and the risk of laxative use in schizophrenia treatment

AIM

Constipation is one of the most common adverse effects in schizophrenia treatment, and it can sometimes cause severe gastrointestinal disease. However, the results of association studies between constipation and psychotropic medications in patients with schizophrenia are inconsistent. Therefore, we investigated the characteristics of psychotropic and laxative prescriptions at discharge in patients with schizophrenia to clarify the association between psychotropics and constipation.

METHODS

We analyzed the data of 139 patients with schizophrenia with or without laxative prescriptions at discharge from eight institutions in 2020.

RESULTS

Sixty-two patients were prescribed laxatives at discharge. The prescription of benzodiazepines in the laxative use group (66.1%) was significantly higher than that in the non-laxative use group (39.0%) (p = 1.4 × 10-3), and the mean number of benzodiazepines in the laxative use group (1.2 ± 1.1/day) was significantly higher than that in the non-laxative use group (0.7 ± 0.9/day) (p = 2.6 × 10-3). Multivariate logistic regression analyses revealed that benzodiazepine prescriptions were significantly associated with laxative usage (odds ratio, 3.059; 95% confidence interval, 1.523-6.144; p = 2.0 × 10-3).

CONCLUSION

Benzodiazepines may be associated with constipation in patients with schizophrenia. Therefore, clinicians should be cautious when prescribing benzodiazepines for the treatment of schizophrenia.

Exposure to psychotropic drugs and breast cancer risk in patients with bipolar disorder and major depressive disorder: a nested case-control study

Breast cancer is one of the most prevalent and serious types of cancer globally. Previous literature has shown that women with mental illness may have an increased risk of breast cancer, however whether this risk is associated with the use of psychotropic drugs has yet to be elucidated. This study aimed to assess such risk among women with major depressive disorder (MDD) and bipolar disorder (BD). A nested case-control study design was used with data obtained from the Taiwan National Health Insurance Research Database. Logistic regression analysis with adjustments for demographic characteristics, medical and mental comorbidities, and all-cause clinical visits was performed to estimate the risk of breast cancer according to the cumulative defined daily dose (cDDD) of psychotropic drugs. The study included 1564 women with MDD or BD who had breast cancer, and 15,540 women with MDD or BD who did not have breast cancer. After adjusting for important confounders, the long-term use of valproic acid (odds ratio, 95% confidence interval: 0.58, 0.39-0.56, cDDD ≥ 365), citalopram (0.58, 0.37-0.91, cDDD 180-365), and sertraline (0.77, 0.61-0.91, cDDD ≥ 365) was associated with a lower risk of breast cancer compared to a cDDD < 30. The short-term use of fluvoxamine (0.82, 0.69-0.96, cDDD 30-180), olanzapine (0.54, 0.33-0.89, cDDD 30-179), risperidone (0.7, 0.51-0.98, cDDD 30-179), and chlorpromazine (0.48, 0.25-0.90, cDDD 30-179) was associated with a lower risk of breast cancer. We found no evidence of an increased risk of breast cancer in patients with MDD or BD receiving psychotropic drugs.

Real-World Treatment of Schizophrenia in Adults With a 22q11.2 Microdeletion: Traitement dans le monde réel de la schizophrénie chez des adultes atteints du syndrome de microdélétion 22q11.2

OBJECTIVE

One in every 4 individuals born with a 22q11.2 microdeletion will develop schizophrenia. Thirty years of clinical genetic testing capability have enabled detection of this major molecular susceptibility for psychotic illness. However, there is limited literature on the treatment of schizophrenia in individuals with a 22q11.2 microdeletion, particularly regarding the issue of treatment resistance.

METHODS

From a large, well-characterized adult cohort with a typical 22q11.2 microdeletion followed for up to 25 years at a specialty clinic, we studied all 107 adults (49 females, 45.8%) meeting the criteria for schizophrenia or schizoaffective disorder. We performed a comprehensive review of lifetime (1,801 patient-years) psychiatric records to determine treatments used and the prevalence of treatment-resistant schizophrenia (TRS). We used Clinical Global Impression-Improvement (CGI-I) scores to compare within-individual responses to clozapine and nonclozapine antipsychotics. For a subgroup with contemporary data (n = 88, 82.2%), we examined antipsychotics and dosage at the last follow-up.

RESULTS

Lifetime treatments involved on average 4 different antipsychotic medications per individual. Sixty-three (58.9%) individuals met the study criteria for TRS, a significantly greater proportion than for a community-based comparison (42.9%; χ2 = 10.38, df = 1, p < 0.01). The non-TRS group was enriched for individuals with genetic diagnosis before schizophrenia diagnosis. Within-person treatment response in TRS was significantly better for clozapine than for nonclozapine antipsychotics (p < 0.0001). At the last follow-up, clozapine was the most common antipsychotic prescribed, followed by olanzapine, risperidone, and paliperidone. Total antipsychotic chlorpromazine equivalent dosages were in typical clinical ranges (median: 450 mg; interquartile range: 300, 750 mg).

CONCLUSION

The results for this large sample indicate that patients with 22q11.2 microdeletion have an increased propensity to treatment resistance. The findings provide evidence about how genetic diagnosis can inform clinical psychiatric management and could help reduce treatment delays. Further research is needed to shed light on the pathophysiology of antipsychotic response and on strategies to optimize outcomes.

PLAIN LANGUAGE SUMMARY TITLE

Real-world treatment of schizophrenia in adults with a 22q11.2 microdeletion.

Clinical Characteristics of Inpatients with Schizophrenia Spectrum Disorder Treated with Electroconvulsive Therapy: A Population-Level Cross-Sectional Study: Titre: Caractéristiques cliniques des patients hospitalisés présentant un trouble du spectre de la schizophrénie et traités par électrochocs : Une étude de population transversale

OBJECTIVE

Electroconvulsive therapy (ECT) is an evidence-based treatment for schizophrenia when anti-psychotic medications do not sufficiently control symptoms of psychosis or rapid response is required. Little is known about how it is used in routine clinical practice. The aim of this study was to identify the association of demographic and clinical characteristics with administration of ECT for schizophrenia spectrum disorders (SSD).

METHODS

Among psychiatric inpatients with a diagnosis of SSD in Ontario, Canada (2006-2023), patient-level socio-demographic and clinical characteristics were described in those who did and did not receive ECT. We used multi-variable logistic regression to assess the association between patient-level characteristics and administration of ECT during index hospitalization.

RESULTS

From 164,632 admissions, 2,168 (1.3%) involved exposure to ≥1 inpatient ECT procedure. Compared to those not receiving ECT, those receiving ECT were older, had higher rates of pre-admission medication use, medical and psychiatric comorbidities, outpatient mental health service use, but lower rates of substance use disorders. In the multi-variable logistic regression model, patient-level characteristics most strongly associated with receiving inpatient ECT were the presence of catatonia (odds ratio [OR]: 5.83; 95% confidence interval [95% CI]: 4.01-8.46), comorbid depression (OR: 2.49; 95% CI: 2.07-2.98), obsessive-compulsive disorder (OR: 2.16; 95% CI: 1.55-3.00), while characteristics most strongly associated with not receiving inpatient ECT were myocardial infarction (OR: 0.44; 95% CI: 0.20-0.95) and family conflict towards patient (OR: 0.47; 95% CI: 0.31-0.71). Neither severity of psychotic symptoms, non-command auditory hallucinations nor delusions were associated with administration of ECT.

CONCLUSIONS

While characteristics associated with the use of ECT are generally consistent with the indications for ECT (e.g., catatonia, mood disorders), ECT is rarely used amongst individuals with SSD. Severity of psychotic symptoms was not associated with the use of inpatient ECT suggesting an opportunity to increase the use of ECT in this population.

PLAIN LANGUAGE SUMMARY TITLE

Patient characteristics associated with receiving electroconvulsive therapy in schizophrenia and other psychotic illnesses.

Cross-titration from risperidone to clozapine utilizing clozapine serum concentrations: A case report

INTRODUCTION

Clozapine and risperidone are second-generation antipsychotics used in the treatment of schizophrenia. There are no guidelines on cross-titration of antipsychotics and, additionally, there is a paucity of published data to support the potential utility of using serum drug levels to guide dosing in these situations.

CASE REPORT

A 68-year-old female patient with a history of schizophrenia, taking risperidone and fluoxetine, and a recent diagnosis of Parkinson's disease was admitted to the hospital after a fall at home. During the patient's hospital stay, utilizing serum clozapine levels as guidance, the patient was cross-titrated from risperidone 12 mg daily to a final dose of clozapine 75 mg daily over the span of 17 days, in the setting of multiple possible drug-drug interactions.

DISCUSSION

There is no evidence-based guidance on transitioning patients from one antipsychotic to another especially in the setting of drug-drug interactions. In this case, the patient was successfully transitioned from risperidone to clozapine using serum clozapine levels and clinical status to guide decision-making.

CONCLUSIONS

Utilizing serum clozapine levels may be helpful in guiding dose changes during antipsychotic cross-titration, especially when multiple drug interactions are involved.

Investigating DRD2 and HTR2A polymorphisms in treatment-resistant schizophrenia: a comparative analysis with other treatment-resistant mental disorders and the healthy state

This study investigates treatment-resistant schizophrenia (TRS) by analysing genetic markers in dopamine and serotonin receptors. Conducted on a cohort of 221 patients with treatment-resistant mental disorders, the research focused on DRD2 and HTR2A gene variants-specifically, rs1801028, rs6314, rs7997012, and rs6311. The findings suggest specific associations between certain genetic variants and TRS. Notably, the HTR2A rs6314 A|G genotype and rs7997012 G|G genotype were significantly more prevalent in TRS patients compared to healthy controls (HCs). Haplotype analyses revealed associations between specific haplotypes-such as A|G (rs6314-rs7997012)-and TRS, indicating their potential predictive value for TRS versus HCs. The study underscores the involvement of the serotonergic system in TRS. These findings offer valuable insights into the genetic factors contributing to TRS, paving the way for future research and the development of personalised prevention and treatment strategies in psychiatry.

Network analysis of clinical features in patients with treatment-resistant schizophrenia

Objective

This study compares the clinical features of Treatment-Resistant Schizophrenia (TRS) and Non-Treatment-Resistant Schizophrenia (NTRS) using network analysis.

Methods

We recruited 511 patients, dividing them into TRS (N = 269) and NTRS (N = 242) groups. Eight scales were used: Positive and Negative Syndrome Scale (PANSS), Positive Symptom Assessment Scale (SAPS), Scale for Assessment of Negative Symptoms (SANS), Simpson-Angus Scale (SAS), Abnormal Involuntary Movements Scale (AIMS), Barnes Akathisia Rating Scale (BARS), Calgary Schizophrenia Depression Scale (CDSS), and Global Assessment of Functioning Scale (GAF). Demographic and clinical data were analyzed using T-tests and Chi-square tests. Network analysis was then applied to compare clinical features.

Results

Significant differences were found in the overall architectures (S = 1.396, p < 0.002) and edge weights (M = 0.289, p < 0.009) of TRS and NTRS networks. Nine edges (p < 0.05) and five nodes (p < 0.01) differed, indicating a correlation between clinical symptoms of the two groups. TRS core symptoms were linked to social functions through both positive (SAPS) and negative symptoms (SANS), while NTRS core symptoms were related to general psychopathological symptoms (PANSS-G).

Conclusion

For TRS, it is essential to address both negative and positive symptoms, focusing on the impact of negative symptoms on functioning. Additionally, managing medication side effects is crucial to avoid worsening negative symptoms.

Strategies for Achieving Better Cognitive Health in Individuals with Schizophrenia Spectrum: A Focus on the Canadian Landscape: Stratégies pour atteindre une meilleure santé cognitive chez les personnes souffrant du spectre de la schizophrénie : un regard sur le paysage canadien

BACKGROUND

Schizophrenia spectrum disorders (SSDs) are a group of psychiatric disorders characterized by positive and negative symptoms as well as cognitive impairment that can significantly affect daily functioning.

METHOD

We reviewed evidence-based strategies for improving cognitive function in patients with SSDs, focusing on the Canadian landscape.

RESULTS

Although antipsychotic medications can address the positive symptoms of SSDs, cognitive symptoms often persist, causing functional impairment and reduced quality of life. Moreover, cognitive function in patients with SSDs is infrequently assessed in clinical practice, and evidence-based recommendations for addressing cognitive impairment in people living with schizophrenia are limited. While cognitive remediation (CR) can improve several domains of cognitive function, most individuals with SSDs are currently not offered such an intervention. While the development of implementation strategies for CR is underway, available and emerging pharmacological treatments may help overcome the limited capacity for psychosocial approaches. Furthermore, combining pharmacological with non-pharmacological interventions may improve outcomes compared to pharmacotherapy or CR alone.

CONCLUSION

This review highlights the challenges and discusses the potential solutions related to the assessment and management of cognitive impairment to help mental health-care practitioners better manage cognitive impairment and improve daily functioning in individuals with SSDs.

PLAIN LANGUAGE SUMMARY TITLE

Improving Thinking Skills in People With Schizophrenia: A Focus on Canada.

Should we consider microbiota-based interventions as a novel therapeutic strategy for schizophrenia? A systematic review and meta-analysis

Schizophrenia is a chronic psychiatric disorder characterized by a variety of symptoms broadly categorized into positive, negative, and cognitive domains. Its etiology is multifactorial, involving a complex interplay of genetic, neurobiological, and environmental factors, and its neurobiology is associated with abnormalities in different neurotransmitter systems. Due to this multifactorial etiology and neurobiology, leading to a wide heterogeneity of symptoms and clinical presentations, current antipsychotic treatments face challenges, underscoring the need for novel therapeutic approaches. Recent studies have revealed differences in the gut microbiome of individuals with schizophrenia compared to healthy controls, establishing an intricate link between this disorder and gastrointestinal health, and suggesting that microbiota-targeted interventions could help alleviate clinical symptoms. Therefore, this meta-analysis investigates whether gut microbiota manipulation can ameliorate psychotic outcomes in patients with schizophrenia receiving pharmacological treatment. Nine studies (n = 417 participants) were selected from 81 records, comprising seven randomized controlled trials and two open-label studies, all with a low risk of bias, included in this systematic review and meta-analysis. The overall combined effect size indicated significant symptom improvement following microbiota treatment (Hedges' g = 0.48, 95% CI = 0.09 to 0.88, p = 0.004, I2 = 62.35%). However, according to Hedges' g criteria, the effect size was small (approaching moderate), and study heterogeneity was moderate based on I2 criteria. This review also discusses clinical and preclinical studies to elucidate the neural, immune, and metabolic pathways by which microbiota manipulation, particularly with Lactobacillus and Bifidobacterium genera, may exert beneficial effects on schizophrenia symptoms via the gut-brain axis. Finally, we address the main confounding factors identified in our systematic review, highlight key limitations, and offer recommendations to guide future high-quality trials with larger participant cohorts to explore microbiome-based therapies as a primary or adjunctive treatment for schizophrenia.

Gut microbiota of patients insusceptible to olanzapine-induced fatty liver disease relieves hepatic steatosis in rats

Olanzapine-induced fatty liver disease continues to pose vital therapeutic challenges in the treatment of psychiatric disorders. In addition, we observed that some patients were less prone to hepatic steatosis induced by olanzapine. Therefore, we aimed to investigate the role and the underlying mechanism of the intestinal flora in olanzapine-mediated hepatic side effects and explore the possible countermeasures. Our results showed that patients with different susceptibilities to olanzapine-induced fatty liver disease had different gut microbial diversity and composition. Furthermore, we performed fecal microbiota treatment (FMT), and confirmed that the gut microbiome of patients less prone to the fatty liver caused by olanzapine exhibited an alleviation against fatty liver disease in rats. In terms of mechanism, we revealed that the cross talk of leptin with the gut-short-chain fatty acid (SCFA)-liver axis play a critical role in olanzapine-related fatty degeneration in liver. These findings propose a promising strategy for overcoming the issues associated with olanzapine application and will hopefully inspire future in-depth research of fecal microbiota-based therapy in olanzapine-induced fatty liver disease.NEW & NOTEWORTHY Patients who were less inclined to have olanzapine-induced fatty liver had different gut microbiota profiles than did those in the susceptible cohort. Lachnospiraceae, Ruminococcaceae, Oscillospiraceae, Butyricicoccaceae, and Christensenellaceae were enriched in patients who were less prone to fatty liver disease caused by olanzapine. Fecal microbiota treatment (FMT) with these fecal samples promoted short-chain fatty acid (SCFA) production, which attenuated the circulating leptin and inhibited FASN and ACC1, thereby suppressing lipid synthesis in the liver, ultimately leading to alleviation of hepatic steatosis.

The factors associated with clozapine polypharmacy for schizophrenia patients discharged from a large public psychiatric hospital in Taiwan, 2006-2021

Clozapine treatment continues to be recognized as the gold standard for managing treatment-resistant schizophrenia. Combining clozapine with other antipsychotics (i.e., clozapine polypharmacy) has emerged as an option for clozapine-resistant schizophrenia. We aimed to investigate the factors associated with clozapine polypharmacy in schizophrenia patients discharged on clozapine from a public psychiatric hospital. The analysis included patients with schizophrenia who were discharged between 2006 and 2021 and prescribed clozapine upon discharge. All patients were divided into 2 groups: clozapine monotherapy and clozapine polypharmacy. Multivariate logistic regression was used to identify factors associated with clozapine polypharmacy. A total of 1396 (42.7%) schizophrenia patients discharged on clozapine polypharmacy. In a multivariate logistic regression model, the clozapine polypharmacy was more likely to be male gender, to be younger, to be earlier age of onset, to have a greater number of previous hospitalizations, to have a shorter length of hospital stay, and to have a lower clozapine daily dose. The prevalence of clozapine significantly increased from 22.4% in 2006 to 50% in 2021. Compared with clozapine monotherapy, clozapine polypharmacy was associated with male gender, younger, earlier age of onset, a greater number of previous hospitalizations, shorter length of hospital stay, and lower clozapine daily dose. The utilization of clozapine polypharmacy has seen a significant increase over time. Further research is necessary to clarify its efficacy, safety, and overall risk/benefit ratio.

Long-term effectiveness of aripiprazole once monthly on functioning and quality of life in schizophrenia: results of year 2 of the ReLiAM study

BACKGROUND

Aripiprazole once-monthly (AOM) has proven effective in the treatment of schizophrenia, although little is known about its impact on global functioning and quality of life beyond 1 year. Here, we investigate the continued impact of AOM on the participants of the ReLiAM study during the second year of follow-up.

METHODS

The participants who were evaluated at ≥ 1 time point during the second year of the ReLiAM study (months 15, 18, 21, and 24; year 1 completers) were assessed via the GAF scale. Secondary outcomes were reported on the SOFAS, CGI-S, and QLS.

RESULTS

109 (86%) completed at least 1 post-12-month visit and 33 (30.3%) patients completed the final assessment at month 24. The improvements observed in the year 1 completers in GAF total score were maintained through to year 2 completers. The improvements in CGI-S and SOFAS that were observed at the end of year 1 were also maintained through the end of the second year. Similar trends of sustained improvement in GAF total score, CGI-S score, and SOFAS were observed in the post-hoc analyses of the year 2 completers. Seventy-four percent (74.3%) of year 1 completers experienced mild treatment-emergent adverse events during the second year, the most frequently reported being weight gain, akathisia, and insomnia. Seventeen percent (17.4%) experienced serious adverse events. Similar findings regarding effectiveness and tolerability were reported in the year 1 completers and in year 2 completers.

CONCLUSIONS

These findings suggest that the favorable effectiveness, including tolerability observed during the first year following AOM initiation, are maintained and may even continue to improve during the second year of treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02131415, first posted on May 6, 2014. Overall trial status: Terminated.

The importance of incorporation of real-world evidence into the guidelines on the pharmacological treatment of schizophrenia

The quantity and quality of real-world data and real-world evidence in schizophrenia research are at a high level. However, these results are not included in the grading systems used to develop treatment guidelines for schizophrenia. A meta-analysis and a network meta-analysis have independently provided evidence that the results of randomized clinical trials in schizophrenia adequately translate to real-world settings. The authors propose the incorporation of a synthesis of evidence derived from analyses of randomized controlled trials and real-world data as a novel and highest level of evidence in grading instruments used to develop treatment guidelines for schizophrenia.

Clozapine Toxicity Predictor: Deep neural network model predicting clozapine toxicity and its therapeutic dose range

Clozapine is the gold standard for treatment-resistant schizophrenia; however, its superior efficacy is accompanied by potentially serious adverse events (neutropenia, seizures, constipations, pneumonia), many of which are also concentration-dependent. As such, clozapine dose titration should be guided by therapeutic drug monitoring (TDM). However, access to TDM is often limited. The present study describes a new deep neural network that can predict the concentrations, toxicity and therapeutic dose range for clozapine and norclozapine. The model was trained on basic clinical data (biological sex, age, clozapine daily dose, BMI, CRP and number of CYP 1A2 and 3A4 substrates, inhibitors and inducers) from 69 patients with treatment-refractory patients treated with different clozapine doses. Our findings provide the training efficacy data for the model, as well as an analysis of clozapine and norclozapine blood concentrations in a test group of three additional patients, to demonstrate its practical capabilities. The model is licensed on a free and permissive 2-Clause BSD license and is available to all clinicians; it can be accessed as a web application, available at https://csk.umed.pl/clotop.

Personality disorders and schizophrenia spectrum disorders in the Italian forensic psychiatric population: clinical features, pattern of violence and treatment

Starting in 2015, the Residencies for Execution of Security Measures (REMS) became the place of treatment and care for dangerous offenders who were acquitted due to a mental disorder in Italy. Schizophrenia spectrum disorders (SSD) and personality disorders (PD) are the most common psychiatric disorders among REMS patients. This study aimed to identify and describe potential clinical, therapeutic, and criminal-related differences in REMS patients with SSD and PD. A sample of 528 REMS patients extracted from a previous observational retrospective study underwent secondary analysis. The group of PD patients (n = 150) comprised more females (p < 0.001) and had a higher frequency of substance abuse (p < 0.001) than the SSD group (n = 378). The SSD group was more frequently admitted to the REMS due to homicide/attempted homicide (p < 0.001). Among SSD patients, we found a higher recognition of criminal irresponsibility (p < 0.001). Patients with PD were more likely to engage in violent behavior in the REMS than their SSD counterparts (p < 0.001). Patients with SSD were more likely to receive antipsychotic polypharmacy (p < 0.05) and a higher dose of antipsychotics (p < 0.001). These initial results provide empirical evidence to support the need for personalized forensic treatment paths.

State of the Science: The Hierarchical Taxonomy of Psychopathology (HiTOP)

The Hierarchical Taxonomy of Psychopathology (HiTOP) is a dimensional framework for psychopathology advanced by a consortium of nosologists. In the HiTOP system, psychopathology is grouped hierarchically from super-spectra, spectra, and subfactors at the upper levels to homogeneous symptom components and maladaptive traits and their constituent symptoms, and maladaptive behaviors at the lower levels. HiTOP has the potential to improve clinical outcomes by planning treatment based on symptom severity rather than heterogeneous diagnoses, targeting treatment across different levels of the hierarchy, and assessing distress and impairment separately from the observed symptom profile. Assessments can be performed according to this framework with the recently developed HiTOP-Self-Report (HiTOP-SR). Examples of how to use HiTOP in clinical practice are provided for the internalizing spectrum, including the use of the Unified Protocol and other modularized treatments, measurement-based care, psychopharmacology, and in traditionally underserved populations. Future directions are discussed in this State of the Science review including HiTOP's use in further developing transdiagnostic treatments, extending the model to include other information such as environmental factors, establishing the treatment utility of clinical assessment for the HiTOP-SR, developing new treatments, and disseminating the model.

Antipsychotic prescribing practices and their association with rehospitalization in a forensic psychiatric sample

While there is extensive literature examining the effectiveness of antipsychotic prescribing to patients with schizophrenia spectrum or other psychotic disorders in general psychiatric services, there is a dearth of studies examining antipsychotic prescribing practices and their effectiveness in forensic psychiatric services. Forensic psychiatric patients have unique challenges often due to their high-profile offences, public scrutiny, and legal requirements. This longitudinal, retrospective study aimed to examine antipsychotic prescribing and rehospitalization rates in a forensic psychiatric sample, along with relevant socio-demographic, clinical, and forensic characteristics. All patients had a psychotic illness and were prescribed antipsychotic medication. The sample included 153 patients, of which the majority were male (85.6%), Caucasian (71.2%), middle aged (30s to 50s), had schizophrenia or schizoaffective disorder (76.5%), had a substance use disorder (62.1%), and had a most serious index offence against the person (80.4%). Atypical antipsychotics accounted for the majority of antipsychotic prescriptions (75.9%) and the sample had an antipsychotic polypharmacy rate of 39.9%. The sample was divided into four primary antipsychotic formulation types, which were oral (34.0%), injection (39.2%), clozapine (19.0%), and subtherapeutic (7.8%). Regarding rehospitalization, 52.9% of the sample was rehospitalized, with the average number of rehospitalizations being 1.2 (SD = 1.7) and proportion of the follow up period rehospitalized being 16.4% (SD = 27.7%). Patients prescribed clozapine had numerically lower rates of rehospitalization than those prescribed oral and injection formulation types, but it was not statistically significant. With a 19.0% prescription rate, clozapine may be underutilized in this sample. Further research is needed to demonstrate the potential benefits of clozapine regarding rehospitalization in forensic psychiatric patients, as has already been done in general psychiatry. Advancing treatment of the high-profile forensic population can reduce stigma toward people with mental illness and criminal justice involvement.

Risperidone ISM®: review and update of its usefulness in all phases of schizophrenia

One of the most important challenges in the management of patients with schizophrenia is to ensure adherence to antipsychotic treatment. The contribution of long-acting injectables (LAI) is undeniable in this matter, but there are still some unmet medical needs not covered by these drugs (e.g. quick onset of action for patients with acute exacerbation of schizophrenia). This article summarises the pharmacokinetics, efficacy and safety of Risperidone ISM (in situ microparticles). The aim of this review is to provide information about the potential uses of this new LAI formulation of risperidone for the treatment of schizophrenia, contextualising and diving into the published evidence. Risperidone ISM shows a rapid release which allows achieving within 12 h risperidone active moiety levels similar to those observed in the steady-state for oral risperidone treatment, achieving a mean average concentration of 38.63 ng/mL. The plasma concentration of active moiety achieved by Risperidone ISM comes with a predictable dopamine D2 receptor occupancy above 65% throughout the 28-day dosing period, which is accepted as a threshold for the efficacy of the antipsychotic treatment. This can be associated with the positive efficacy findings throughout its clinical development. In the short term, it provides an early and progressive reduction of symptoms in adult patients with acute exacerbation of schizophrenia without the need for loading doses or oral risperidone supplementation, which could contribute to reinforcing the therapeutic alliance between the patient and the psychiatrist. In addition, long-term treatment was effective, safe and well tolerated regardless of the initial disease severity or whether patients were previously treated with Risperidone ISM during an acute exacerbation or switched from stable doses of oral risperidone. Improvement and maintenance of personal and social functioning and health-related quality of life were observed in each setting, respectively. All these findings endorse Risperidone ISM as a useful and valuable treatment for the acute and maintenance management of patients with schizophrenia.

Adjunctive methylphenidate extended release in patients with schizophrenia: Protocol of a single-centre fixed dose cross-over open-label trial to improve functional and cognitive outcomes

Background

Cognitive symptoms, among the core symptoms of schizophrenia, are associated with poor functional outcome and burden of illness. To date, there is no effective pharmacological treatment for these symptom clusters. Augmentation with psychostimulants has been proposed as a potential treatment option.

Objectives

The present study aims to assess off-label use of adjunctive methylphenidate extended release (ER) in patients with schizophrenia who are stable on antipsychotic medications, and to assess its efficacy on functioning and cognitive outcome.

Methods

This is a single centre study at the Royal Ottawa Mental Health Centre. An open-label fixed dose controlled cross-over trial is planned. Eligible participants will be randomized into one of two arms of the study: 1) four weeks of add-on methylphenidate ER 36 mg, or 2) four weeks of treatment as usual. At 4 weeks, participants will switch arms. The duration of the study includes 8 weeks of treatment and a follow-up visit at 12 weeks. Primary outcome measures include tablet-based tests of functioning and cognition (VRFCAT and BAC) and will be administered at baseline and every 4 weeks. We are aiming to recruit a total of 24 participants.

Expected outcomes

The proposed project intends to assess a potential treatment option for cognitive deficits of schizophrenia, for which there are no recommendations by current treatment guidelines. The novelty and significance of the current study is that it investigates this intervention and assess applicability of it in a "real world setting" in a tertiary care hospital.

Trajectories of daily antipsychotic use and weight gain in people hospitalized for the first episode of psychosis

BACKGROUND

We need to better understand the risk factors and predictors of medication-related weight gain to improve metabolic health of individuals with schizophrenia. This study explores how trajectories of antipsychotic medication (AP) use impact body weight early in the course of schizophrenia.

METHODS

We recruited 92 participants with first-episode psychosis (FEP, n = 92) during their first psychiatric hospitalization. We prospectively collected weight, body mass index (BMI), metabolic markers, and exact daily medication exposure during 6-week hospitalization. We quantified the trajectory of AP medication changes and AP polypharmacy using a novel approach based on meta-analytical ranking of medications and tested it as a predictor of weight gain together with traditional risk factors.

RESULTS

Most people started treatment with risperidone (n = 57), followed by olanzapine (n = 29). Then, 48% of individuals remained on their first prescribed medication, while 33% of people remained on monotherapy. Almost half of the individuals (39/92) experienced escalation of medications, mostly switch to AP polypharmacy (90%). Only baseline BMI was a predictor of BMI change. Individuals in the top tercile of weight gain, compared to those in the bottom tercile, showed lower follow-up symptoms, a trend for longer prehospitalization antipsychotic treatment, and greater exposure to metabolically problematic medications.

CONCLUSIONS

Early in the course of illness, during inpatient treatment, baseline BMI is the strongest and earliest predictor of weight gain on APs and is a better predictor than type of medication, polypharmacy, or medication switches. Baseline BMI predicted weight change over a period of weeks, when other traditional predictors demonstrated a much smaller effect.

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

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

Antipsychotic prescription patterns among schizophrenia patients in Guangdong Province, China's 686 program: A retrospective study

Schizophrenia is a severe mental disorder. However, there is limited data on the prescribing patterns of patients under China's Central Government Support for the Local Management and Treatment of Severe Mental Illnesses Program, known as the "686 program." This study aimed to investigate the use of antipsychotic medications and associated factors among discharged schizophrenia patients in Guangdong Province, within the 686 Program. This study encompassed schizophrenia patients who were discharged from the Affiliated Brain Hospital, Guangzhou Medical University and enrolled in the 686 Program between January 2019 and December 2019. A total of 1645 hospitalized schizophrenia patients were included in the analysis. Clinical and sociodemographic data were acquired from medical records upon discharge. A total of 15 unique antipsychotic medications were utilized, comprising 4 first-generation (FGAs) and 11 second-generation (SGAs) options. FGAs were prescribed at a rate of 8.3%, while SGAs dominated at 98.8%. Risperidone (40.8%), olanzapine (30.2%), clozapine (24.6%), and amisulpride (15.4%) emerged as the top 4 prescribed medications. Additionally, mood stabilizers were used by 20.4%, antidepressants by 14.8%, sedative-hypnotics by 33.6%, anticholinergics by 26.9%, and other internal medicine drugs by 46.4%. Notably, 60.5% received antipsychotic monotherapy (AMT), while 39.5% underwent antipsychotic polypharmacy (APP). Predictors of polypharmacy included multiple hospital admissions, longer hospital stays, and undergoing modified Electroconvulsive Therapy (mECT) during hospitalization. In Guangdong Province, China's 686 Program, hospitalized patients commonly receive multiple antipsychotic medications simultaneously. Due to the varying outcomes in current studies on the benefits and risks of polypharmacy, it's vital to educate psychiatrists about the importance of AMT to reduce APP. Additionally, randomized, controlled trials are essential to identify the safest and most effective antipsychotic combinations, as well as to understand which patient profiles may benefit from these combinations.

Treatment of Cognitive Impairment Associated with Schizophrenia Spectrum Disorders: New Evidence, Challenges, and Future Perspectives

Cognitive impairment associated with schizophrenia (CIAS) represents one of the core features of the disorder and has a significant impact on functional and rehabilitation outcomes of people living with schizophrenia spectrum disorders (SSD). The aim of this critical review is to highlight the most recent evidence on effective treatments available for CIAS, to discuss the current challenges in this field, and to present future perspectives that may help to overcome them. Concerning psychopharmacological approaches, among the most indicated strategies for the management and prevention of CIAS is to favor second-generation antipsychotic medications and avoid long-term and high-dose treatments with anticholinergic medications and benzodiazepines. Moreover, non-pharmacological approaches such as cognitive remediation and physical exercise-based programs represent evidence-based interventions in the treatment of CIAS that have shown reliable evidence of effectiveness on both cognitive and functional outcomes. These treatments, however, are still delivered to people accessing mental health services with a diagnosis of CIAS in an uneven manner, even in high-income countries. Academic and clinical partnership and collaboration, as well as advocacy from service users, families, carers, and stakeholders' organizations could help to reduce the bench to bedside gap in the treatment of CIAS. Future perspectives include the development of novel pharmacological agents that could be effective in the treatment of CIAS, the implementation of novel technologies such as telemedicine and virtual reality in the delivery of evidence-based interventions to improve accessibility and engagement, and further research in the field of non-invasive brain stimulation.

Efficacy and acceptability of interventions to reduce antipsychotic polypharmacy: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Antipsychotic polypharmacy (APP) is frequent but evidence-based guidelines on reducing APP to antipsychotic monotherapy (APM) are sparse. We aimed to systematically review clinical interventions randomizing patients to reducing APP to APM versus continuing APP.

METHODS

Systematic literature review searching Medline and Embase (latest search January 10, 2024) for randomized clinical trials (RCTs) studying interventions comparing individuals randomized to reduction of APP to APM with individuals continuing on APP. Two independent reviewers performed the literature screening, data extraction, and risk of bias assessment (RoB2). We performed random effects meta-analyses on the main outcome all-cause discontinuation/"acceptability" of the treatment strategy and secondary outcomes change in psychopathology, functional level, and side effects.

RESULTS

The search identified 4672 hits, whereof 8 trials (N = 1204, 6 patient-level RCTs and 2 cluster-RCTs) were included, primarily in patients with schizophrenia. All trials were associated with high risk of bias. Compared to APP continuation, reduction to APM was associated with no significant change in all-cause discontinuation (studies = 6, n = 455, RR = 1.48, 95%CI = 0.74-2.95, I2 = 78 %) or inefficacy-related discontinuation (studies = 5, n = 351, RR = 1.60, 95%CI = 0.46-5.55, I2 = 70 %). Patients randomized to APM showed a trend towards greater reduction in psychopathology (studies = 5, n = 244, SMD = -0.24, 95%CI = -0.49, 0.02, I2 = 0 %) but no difference in functional level nor side effects. The cluster-RCTs found that interventions at the departmental level can result in lower rates of APP.

CONCLUSION

Although switching patients from APP to APM can be a viable approach, too few RCTs exist on this important topic. Clinicians need to evaluate potential benefits and risks of APP and APM on an individual basis.

PROSPERO REGISTRATION

CRD42022329955.

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

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

The European psychiatric association (EPA) - early career psychiatrists committee survey on trainees' and early-career psychiatrists' attitudes towards therapeutic drug monitoring (TDM) use and utility during antipsychotic treatment

OBJECTIVES

This survey assessed psychiatry residents'/early-career psychiatrists' attitudes towards the utility of therapeutic drug monitoring (TDM) of antipsychotics.

METHODS

A previously developed questionnaire on attitudes on TDM utility during antipsychotic treatment was cross-sectionally disseminated by national coordinators between 01/01/2022-31/12/2023. The frequency of using TDM for antipsychotics other than clozapine was the main outcome in a linear regression analysis, including sex, clinical setting, caseload, and factors generated by an exploratory factor analysis. Comparisons between residents and early-career psychiatrists, respondents working in in- and outpatient settings, and low-/middle- and high-income countries were performed.

RESULTS

Altogether, 1,237 respondents completed the survey, with 37.9% having never used TDM for antipsychotics. Seven factors explained 41% of response variance; six of them were associated with frequency of TDM use (p < 0.05). Items with highest loadings for factors included clinical benefits of TDM (factors A and E: 0.7), negative expectations for beliefs of patients towards TDM (factor B: 0.6-0.7), weak TDM scientific evidence (factor C: 0.8), and TDM availability (factor D: -0.8). Respondents from low-/middle-income countries were less likely to frequently/almost always use TDM compared to high-income countries (9.4% vs. 21.5%, p < 0.001).

DISCUSSION

TDM use for antipsychotics was poor and associated with limited knowledge and insufficient availability.

Changes in psychopharmacotherapy for patients with schizophrenia in a psychiatric institution in Japan: A 12-year prescription survey pre- and post-introduction of clozapine

Psychopharmacotherapy for patients with schizophrenia in Japan has a long history of polypharmacy, which is rare worldwide but remains a critical problem. One reason for this is that clozapine was not available in Japan until 2009. We aimed to investigate the changes in psychopharmacotherapy in patients with schizophrenia over 12 years pre- and post-introduction of clozapine to clarify how psychopharmacotherapy for patients with schizophrenia has changed with the introduction of clozapine. We retrospectively collected data from the medical records of inpatients diagnosed with schizophrenia at the Okayama Psychiatric Medical Center. Chlorpromazine equivalent (CP-eq) decreased from 1276.6 mg/day in 2009 to 613.9 mg/day in 2020. The prescribed daily dose/defined daily dose (PDD/DDD) decreased from 3.0 in 2009 to 1.2 in 2020. The monotherapy rate increased from 24.4 % in 2009 to 74.6 % in 2020. Our institution began using clozapine in 2010, and the prescription rate for clozapine increased to 37.3 % in 2020. The prescription rate for more than three antipsychotics decreased from 27.8 % in 2009 to 0.8 % in 2020. The increase in clozapine prescription has contributed to an increased rate of antipsychotic monotherapy and a decreased rate of polypharmacy, promoting the optimization of schizophrenia medication. Clozapine therapy should be further promoted in Japan to reduce treatment-resistant schizophrenia due to polypharmacy as much as possible.

A systematic review of clozapine for aggression and violence in patients with schizophrenia or schizoaffective disorder

Although uncommon, the risk of aggression and violence is greater in people with schizophrenia than in the general population. Clozapine is the "gold standard" pharmacologic treatment for the management of persistent agitation and aggression in people with schizophrenia and is consistently recommended by guidelines and reviews for this purpose. Although clozapine is indicated for treatment-resistant schizophrenia based on its superior efficacy, studies have proposed that clozapine may have specific properties that ameliorate aggression and hostility that are distinct from its antipsychotic effects. A literature review was conducted on June 3, 2023, using the US National Library of Medicine's PubMed resource to identify articles focusing on clozapine for the treatment of aggression, violence, and/or hostility in patients with schizophrenia or schizoaffective disorder. The majority of evidence, including from randomized control trials, supports the utilization of clozapine as maintenance treatment for persistent aggressive behavior in patients with schizophrenia, and supports that its anti-aggressive effects may be independent from its antipsychotic properties (e.g. - treatment of hallucinations and delusions). Future randomized control studies evaluating clozapine and clozapine serum levels with aggression as the primary outcome would be of benefit.

Once-daily versus divided dosing regimens of clozapine: A cross-sectional study in Singapore

INTRODUCTION

Clozapine is recognized as the gold standard medication for treatment-resistant schizophrenia. Despite the general recommendation of administering in a divided dosing regimen, clozapine is often prescribed once daily at night in clinical practice. This study aims to compare patient characteristics, psychiatric symptoms, side effects, and plasma concentration of clozapine between once-daily dosing and divided dosing regimens.

METHODS

This cross-sectional study included 159 participants with treatment-resistant schizophrenia or schizoaffective disorder. Participant's demographic information, anthropometric data, and medical history were collected. Their psychiatric symptoms, cognition, functioning, and side effects were evaluated.

RESULTS

Once-daily dosing regimen was associated with younger age and competitive employment. Lower clinical symptom severity, better functioning and cognitive performance were observed in the once-daily dosing group. Lower daily dose of clozapine, trough plasma concentrations of clozapine and norclozapine were also significantly associated with once-daily dosing regimen.

CONCLUSION

The study results support once-daily dosing of clozapine as a viable option to selected patients in clinical practice, as no association of severe symptoms or side effects were associated with once-daily dosing regimen. More studies are needed to examine the relationship between clinical outcomes and clozapine dosing regimen.

Estrogens prevent the hypothalamus-periphery crosstalk induced by olanzapine intraperitoneal treatment in female mice: Effects on brown/beige adipose tissues and liver

Olanzapine (OLA) is a highly obesogenic second-generation antipsychotic (SGA). Recently we demonstrated that, contrarily to OLA oral treatment, intraperitoneal (i.p.) administration resulted in weight loss and absence of hepatic steatosis in wild-type (WT) and protein tyrosine phosphatase 1B (PTP1B)-deficient (KO) male mice. This protection relied on two central-peripheral axes connecting hypothalamic AMPK with brown/inguinal white adipose tissue (BAT/iWAT) uncoupling protein-1 (UCP-1) and hypothalamic JNK with hepatic fatty acid synthase (FAS). Herein, we addressed OLA i.p. treatment effects in WT and PTP1B-KO female mice. Contrarily to our previous results in WT females receiving OLA orally, the i.p. treatment did not induce weight gain or hyperphagia. Molecularly, in females OLA failed to diminish hypothalamic phospho-AMPK or elevate BAT UCP-1 and energy expenditure (EE) despite the preservation of iWAT browning. Conversely, OLA i.p. treatment in ovariectomized mice reduced hypothalamic phospho-AMPK, increased BAT/iWAT UCP-1 and EE, and induced weight loss as occurred in males. Pretreatment of hypothalamic neurons with 17β-estradiol (E2) abolished OLA effects on AMPK. Moreover, neither hypothalamic JNK activation nor hepatic FAS upregulation were found in WT and PTP1B-KO females receiving OLA via i.p. Importantly, this axis was reestablished upon ovariectomy. In this line, E2 prevented OLA-induced phospho-JNK in hypothalamic neurons. These results support the role of estrogens in sex-related dimorphism in OLA treatment. This study evidenced the benefit of OLA i.p. administration in preventing its obesogenic effects in female mice that could offer clinical value.

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.

Clozapine Use Among People With Psychotic Disorders Who Experience Specific Indications for Clozapine

Objective: To examine rates of clozapine use among people with psychotic disorders who experience specific indications for clozapine.

Methods: Records data from 11 integrated health systems identified patients aged 18 years or older with recorded International Classification of Diseases, Tenth Revision, Clinical Modification, diagnoses of schizophrenia, schizoaffective disorder, or other psychotic disorder who experienced any of the 3 events between January 1, 2019, and December 31, 2019, suggesting indications for clozapine: a diagnosis of self-harm injury or poisoning, suicidal ideation diagnosed or in response to standardized assessments, and hospitalization or emergency department (ED) care for psychotic disorder despite treatment with 2 or more antipsychotic medications. Prescription dispensing data identified all clozapine use prior to or in the 12 months following each indication event. Analyses were conducted with aggregate data from each health system; no individual data were shared.

Results: A total of 7,648 patients with psychotic disorder diagnoses experienced at least 1 indication event. Among 1,097 experiencing a self-harm event, 32 (2.9%) had any prior clozapine use, and 10 (0.9%) initiated clozapine during the following 12 months. Among 6,396 with significant suicidal ideation, 238 (3.7%) had any prior clozapine use, and 70 (1.1%) initiated clozapine over 12 months. Among 881 with hospitalization or ED visit despite pharmacotherapy, 77 (8.7%) had any prior clozapine treatment, and 41 (4.7%) initiated clozapine over 12 months. Among those with significant suicidal ideation, rates of both prior clozapine treatment and subsequent initiation varied significantly by race and ethnicity, with rates among Hispanic and non-Hispanic Black patients lower than among non Hispanic White patients.

Conclusions: Initiating clozapine treatment is uncommon among people with psychotic disorders who experience events suggesting clozapine is indicated, with even lower rates among Black and Hispanic patients.

Association of Antipsychotic Polypharmacy and Two-Year All-Cause Mortality: A Population-Based Cohort Study of 33,221 Italian Continuous Users

Background: Differences in survival between patients treated with antipsychotic monotherapy vs. polytherapy are debated. This study aimed to examine the association of antipsychotic polytherapy with 2-year all-cause mortality in a population-based cohort. Methods: Data were retrieved from healthcare databases of four local health units of Lombardy, Italy. Subjects aged 18-79 years who received continuous antipsychotic prescriptions in 2018 were identified. Overall survival among patients with antipsychotic monotherapy vs. polytherapy was compared. A multivariate Cox PH model was used to estimate the association between antipsychotic therapy, or antipsychotic use (continuous vs. non-continuous), and all-cause mortality. Adjustments were made for the presence of metabolic disturbances, total antipsychotic dosage amount (olanzapine equivalent doses), age, and sex. Results: A total of 49,875 subjects receiving at least one prescription of antipsychotics during 2018 were identified. Among the 33,221 patients receiving continuative antipsychotic prescriptions, 1958 (5.9%) experienced death from any cause at two years. Patients with continuous antipsychotic use had a 1.13-point increased mortality risk compared with non-continuous users. Patients treated with antipsychotic polytherapy showed an adjusted mortality risk increased by 17% (95% CI: 2%, 33%) compared to monotherapy. Conclusions: The study highlights the potential risks associated with antipsychotic polypharmacy, emphasizing the importance of optimizing drug prescriptions to improve patient safety and reduce mortality rates in individuals receiving antipsychotic therapy.

Tolerability and safety outcomes of first-line oral second-generation antipsychotics in patients with schizophrenia

INTRODUCTION

Antipsychotics are the foundation of pharmacologic treatment for schizophrenia. There are many oral antipsychotics available and given that these medications are generally considered comparably efficacious when titrated to an adequate dose, their varied tolerability, and safety profiles become critically important for medication selection.

AREAS COVERED

This paper reviews tolerability and safety considerations for first-line second-generation oral antipsychotics currently approved for the treatment of schizophrenia in the USA. Excluded from consideration are clozapine and non-oral formulations.

EXPERT OPINION

Among antipsychotics, there are many differences in adverse reactions observed in clinical trials, such as variable likelihood to cause sedation vs insomnia, weight gain and abnormalities in glucose/lipid metabolism, hyperprolactinemia, potential for impact on the QT interval, and motoric adverse effects. Additional safety data that can help with medication selection include safety in pregnancy and lactation, and potential for drug-drug interactions. Ultimately, working with patients to personalize treatment by focusing on safety and individual tolerability considerations for various adverse effects can help in building a therapeutic alliance and improving patients' outcomes.

Therapeutic Outcomes of Treatment With Long-Acting Injectable Antipsychotics in Forensic Populations With Schizophrenia-Spectrum Diagnoses

The advantages of long-acting injectable antipsychotics (LAIs) in schizophrenia are well studied. However, forensic involvement is common in schizophrenia, and incarcerated individuals are often excluded from clinical trials. Nonadherence and oral medication diversion in forensic populations with schizophrenia, and the relationship between antipsychotic nonadherence and crime support LAI utilization in this subset of patients. Yet, federal regulations limit data generation in forensic populations. This review characterizes data on therapeutic outcomes of LAIs in correctional populations with schizophrenia-spectrum diagnoses. A search for primary literature was conducted in PubMed. Favorable effects of LAIs were observed on adherence, psychiatric symptomatology, patient satisfaction, health care costs, and frequency of criminal charges. Data were primarily retrospective and included small samples and individuals with historical versus current forensic involvement. Although limited, available literature and insights into the correctional system suggest advantages to LAI use in forensic populations. Barriers to conducting research in correctional settings must be addressed to facilitate further data generation.

Association between olanzapine plasma concentrations and treatment response: A systematic review, meta-analysis and individual participant data meta-analysis

AIMS

By meta-analysing pooled studies and available individual participant data, we aim to provide new insight on olanzapine therapeutic drug monitoring in schizophrenia.

METHOD

We conducted a computerized search of bibliographic databases (Pubmed, Cochrane library, Web of Science and PsycINFO) to identify studies that assessed the relationship between olanzapine plasma concentration and the change in patients' clinical scores. We investigated this relationship with olanzapine plasma level 12h00 post-intake using a random-effects model.

RESULTS

7 studies were included in the pooled data analysis (781 patients). We found no difference in oral dose between responders and non-responders but a significantly higher concentration of 4.50 µg/L in responders (p < 0.01). Olanzapine concentration above the thresholds identified in each study was associated with response (odd ratio = 3.50, p = 0.0007). We identified that non-responder patients showed greater inter-individual variability than responders. In the individual data analysis (159 patients), we found no relationship between dose and clinical response but an association between plasma level and response in the shape of a parabolic curve. The Receiver Operating Characteristic curve found a threshold of 22.07 µg/L to identify responders (96% sensitivity, 86% specificity) and a threshold of 56.47 µg/L to identify a decreased probability of response.

CONCLUSION

In contrast to oral dose, our work confirmed that plasma olanzapine levels are associated with clinical response and should therefore be used to optimise treatment. We determined a treatment response threshold of 22.07 µg/L and suggest that a concentration above the therapeutic window may result in a decreased response.

Clozapine Use in 22q11.2 Deletion Syndrome: A Systematic Review of the Literature

BACKGROUND

22q11.2 deletion syndrome confers significant risk for the development of schizophrenia. While current recommendations regarding the management of psychotic symptoms in affected individuals are generally in keeping with treatment guidelines for general schizophrenia populations, evidence for the use of clozapine has come from case reports and retrospective observational data. As no reviews on the topic currently exist, a systematic review of clozapine use in 22q11.2 deletion syndrome was completed.

METHODS

In November 2023, a literature search was completed using both PubMed and Scopus to identify English-language articles that reported the use of clozapine in humans with 22q11.2 deletion syndrome.

RESULTS

Twenty-six articles describing 57 individuals were deemed eligible for inclusion. Most individuals had a diagnosis of treatment-resistant schizophrenia. Where reported, the mean or median dose of clozapine was relatively low, and the majority of individuals exhibited a good response (approximately 65.5% across individual case reports/series). While seizures were unsurprisingly the most commonly reported serious adverse effect, the majority of individuals were able to remain on (or be restarted on) clozapine by having their dose decreased and/or by adding an anticonvulsant (most commonly valproate).

CONCLUSIONS

This review reaffirms that individuals with 22q11.2 deletion syndrome may benefit from clozapine therapy even at a low dose, assuming they meet criteria for treatment-resistant schizophrenia and provided no contraindications exist. However, given the increased incidence of seizures in 22q11.2 deletion syndrome, the use of prophylactic anticonvulsant therapy should be considered, and hypoparathyroidism/hypocalcemia screened for and corrected before the initiation of clozapine. It is also recommended that clozapine blood levels be monitored.

Effects of aripiprazole on resting-state functional connectivity of large-scale brain networks in first-episode drug-naïve schizophrenia patients

Aripiprazole modulates functional connectivity (FC) between several brain regions in first-episode schizophrenia patients, contributing to improvement in clinical symptoms. However, the effects of aripiprazole on abnormal connections among extensive brain networks in schizophrenia patients remain unclear. We aimed to investigate the effects of 12 weeks of aripiprazole treatment on the FC of large-scale brain networks. Forty-five first-episode drug-naïve schizophrenia patients and 45 healthy controls were recruited for this longitudinal study. Resting-state functional magnetic resonance imaging (fMRI) data were collected at baseline and after 12 weeks of aripiprazole treatment. The patients were classified into those in response (SCHr group) and non-response (SCHnr group) according to the improvement of clinical symptoms after 12-weeks treatment. The FC were evaluated for seven large-scale brain networks. In addition, correlation analysis was performed to investigate associations between changes FC of large-scale brain networks and clinical symptoms. Before aripiprazole treatment, schizophrenia patients showed decreased FC of extensive brain networks compared to healthy controls. The 12-week aripiprazole treatment significantly prevented the constantly decreased FC of subcortical network, default mode network and other brain networks in patients with SCHr, in association with the improvement of clinical symptoms. Taken together, these findings have revealed the effects of aripiprazole on FC in large-scale networks in schizophrenia patients, which could provide new insight on interpreting symptom improvement in SCH.

Emergence of Extracellular Vesicles as "Liquid Biopsy" for Neurological Disorders: Boom or Bust

Extracellular vesicles (EVs) have emerged as an attractive liquid biopsy approach in the diagnosis and prognosis of multiple diseases and disorders. The feasibility of enriching specific subpopulations of EVs from biofluids based on their unique surface markers has opened novel opportunities to gain molecular insight from various tissues and organs, including the brain. Over the past decade, EVs in bodily fluids have been extensively studied for biomarkers associated with various neurological disorders, such as Alzheimer's disease, Parkinson's disease, schizophrenia, bipolar disorder, major depressive disorders, substance use disorders, human immunodeficiency virus-associated neurocognitive disorder, and cancer/treatment-induced neurodegeneration. These studies have focused on the isolation and cargo characterization of either total EVs or brain cells, such as neuron-, astrocyte-, microglia-, oligodendrocyte-, pericyte-, and endothelial-derived EVs from biofluids to achieve early diagnosis and molecular characterization and to predict the treatment and intervention outcomes. The findings of these studies have demonstrated that EVs could serve as a repetitive and less invasive source of valuable molecular information for these neurological disorders, supplementing existing costly neuroimaging techniques and relatively invasive measures, like lumbar puncture. However, the initial excitement surrounding blood-based biomarkers for brain-related diseases has been tempered by challenges, such as lack of central nervous system specificity in EV markers, lengthy protocols, and the absence of standardized procedures for biological sample collection, EV isolation, and characterization. Nevertheless, with rapid advancements in the EV field, supported by improved isolation methods and sensitive assays for cargo characterization, brain cell-derived EVs continue to offer unparallel opportunities with significant translational implications for various neurological disorders. SIGNIFICANCE STATEMENT: Extracellular vesicles present a less invasive liquid biopsy approach in the diagnosis and prognosis of various neurological disorders. Characterizing these vesicles in biofluids holds the potential to yield valuable molecular information, thereby significantly impacting the development of novel biomarkers for various neurological disorders. This paper has reviewed the methodology employed to isolate extracellular vesicles derived from various brain cells in biofluids, their utility in enhancing the molecular understanding of neurodegeneration, and the potential challenges in this research field.

Safety of BEN guidelines in clozapine treatment: A Canadian perspective

OBJECTIVE

Unidentified benign ethnic neutropenia (BEN) has been recognized as a factor contributing to clozapine underutilization and discontinuation. Guidelines were implemented to accommodate BEN in Canada, and our main objective was to evaluate clozapine's safety in a sample of Canadian psychiatric patients with BEN.

METHOD

A retrospective chart review was conducted at the Centre for Addiction and Mental Health, Toronto, Canada. Through the clozapine clinic registry, participants were identified who (i) received clozapine using the approved BEN guidelines for hematological monitoring, and (ii) had at least one complete blood count pre- and post-clozapine initiation.

RESULTS

Our sample population was comprised of 41 BEN patients who were African-Caribbean (49 %), African (34 %), African-North American (12 %), Middle Eastern (2 %), and Indian-Caribbean (2 %). There was a significant reduction in hematological alerts for these patients while monitored under BEN guidelines (p < 0.001). The mean within-patient ANC value was not significantly different one year after clozapine initiation compared to the pre-clozapine baseline (p = 0.069). None of the patients discontinued clozapine for hematological reasons.

CONCLUSIONS

Findings demonstrated that patients monitored under the modified hematological guidelines for BEN can be safely treated with clozapine. These findings have important clinical ramifications as increased implementation of BEN guidelines may allow for broader use of clozapine.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

REGISTRATION

PROSPERO registration number, CRD42023402480.

A Naturalistic, Non-interventional Investigation of the Clinical and Sociodemographic Characteristics and Prescription Patterns in Patients With Psychotic Disorders at a Tertiary Care Facility in South Asia

OBJECTIVES

 This study aimed to evaluate the trends in the sociodemographic, clinical, and prescription characteristics of patients with psychotic illnesses seen in the outpatient psychiatry department of a tertiary care facility.

METHODS

 Between March 2021 and April 2022, a cross-sectional, prospective, observational, naturalistic, non-interventional study was conducted. A total of two hundred prescriptions were analyzed. To assess the rationality of prescriptions, World Health Organization (WHO) indicators were also computed.

RESULTS

 With a range of 18 to 75 years, the cohort's mean age was 40.26 years, and its average disease duration was 10.75 years. Sixty-seven patients (68.5%) were diagnosed with schizophrenia. Of the 200 prescriptions that were analyzed, 13 antipsychotic prescriptions were written 343 times. Olanzapine was prescribed as an antipsychotic the most frequently (132, 66%), followed by clozapine (75, 37.5%). Haloperidol (41, 20.5%), trifluoperazine (3, 1.5%), loxapine (1, 0.5%), and flupenthixol depot (1, 0.5%) were the most commonly prescribed typical antipsychotics. 91% (181/200) of patients received prescriptions for other drugs in addition to antipsychotics. Trihexyphenidyl (45%), escitalopram (30%), clonazepam (26.5%), sodium valproate (10%), propranolol (10.5%), and modafinil (9.5%) were the most frequently prescribed concurrent medicines. Forty-eight percent (95/200) of prescriptions demonstrated polypharmacy. Among patients, the frequency of antipsychotic prescriptions was 1 in 44% (88/200), 2 in 36.50% (73/200), 3 in 17% (34/200), 4 in 0.5% (1/200), and 5 again in 0.5% (1/200).  Conclusions: On average, the cohort of the current study was young. The commonest diagnosis was mainly schizophrenia. Atypical antipsychotics accounted for the majority of antipsychotic prescriptions in the current study. In this study, a high prevalence of polypharmacy was noted.

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.

Efficacy and Safety Profiles of Antipsychotic Drugs as Viewed by Psychiatrists: A Comparative Analysis of Cariprazine and Risperidone

BACKGROUND

Physicians hold the belief that the treatment outcomes and the treatment strategy they eventually adopt is largely determined by the differences in medications. Despite numerous studies focusing on the decision-making processes of psychiatrists, including the choice of antipsychotics when prescribing pharmacotherapy, the impact of therapeutic drug profiling on physicians' decision-making remains poorly comprehended.

AIM

The aim of this study is to assess the quantitative differences in perceptions of antipsychotics by psychiatrists using cariprazine and risperidone as examples.

METHODS

A total of 79 psychiatrists were interviewed anonymously in St. Petersburg, Russia. The physicians documented the clinical advantages they perceived drugs to possess relative to one another, following a predetermined principle: A B, A=B, A B (2-AC protocol). The comparison is based on eleven parameters that assess the effectiveness and safety of cariprazine or risperidone. It has been hypothesized that the pattern of responses (qualitative difference) and the degree of preference for each drug (quantitative difference) may not align with the data in the original meta-analyses.

RESULTS

The perception parameter exhibited a greater difference than anticipated (δ - 0.889), while the threshold for differentiating between the drugs was lower (τ - 1.001). The response pattern only aligned with theory by 44.37%. The dispersion of responses was associated with the length of work experience.

CONCLUSION

The perceived difference between the drugs significantly deviates from the theoretical data, both in terms of strength of perception and pattern (quantitative and qualitative differences).