Tolerability of effective high doses of paliperidone palmitate in patients with severe resistant schizophrenia

Healthcare utilization and economics evaluation of paliperidone palmitate once-monthly in schizophrenia: a one-year, real-world, and retrospective mirror image study in China

Background

Investigation and analysis of the changes in healthcare resources and burden of schizophrenia in the real world before and after switching from oral antipsychotics (OAPs) to paliperidone palmitate once-monthly (PP1M) could provide evidence to clinicians and patients for choosing treatment modality and data support for health policy optimization.

Methods

The first dosage of PP1M was set as mirror point, and patients with mirror point between January 2020 and June 2022 were recruited in the study. The differences in treatment patterns, healthcare resource utilization, and costs within one year before and after the mirror point were compared.

Results

A total of 72 patients transitioning from OAPs to PP1M (mean age, 35.33 years; 43.06% female) were included in the study. Of the 72 patients, the application of PP1M resulted in a significant reduction in the hospitalization times, emergency room visits, and direct medical costs (P < 0.001), while the pharmacy cost and total cost increased by 222.57% (P < 0.001) and 16.35% (P < 0.001), respectively; PP1M accounted for 88.48% of the pharmacy cost. For patients with ≥1 hospitalization during the OAPs phase (n = 25), the number of hospitalizations, hospitalization days and hospitalization expenses decreased by more than 90% (P < 0.001). Total one-year expenses decreased by 37.67% (P < 0.001), and pharmacy expenses increased by 185.21% (P < 0.001). For patients with no hospitalizations during the OAPs phase (n = 47), emergency and outpatient visits decreased by 70% (P < 0.001) and 30.27% (P < 0.05), respectively, while the total cost increased by 117.56% (P < 0.001), and the pharmacy cost increased by 260.15% (P < 0.001) after initiation of PP1M treatment.

Conclusion

After the transition to PP1M, the number of hospitalizations and outpatient and emergency department visits reduced, and healthcare resources were conserved. Switching to PP1M may be more economically beneficial for patients with prior hospitalizations while on OAP regimens. The high price of PP1M might be an obstacle to its widespread use.

Long-Acting Injectable Second-Generation Antipsychotics in Seriously Ill Patients with Schizophrenia: Doses, Plasma Levels, and Treatment Outcomes

This research studies the dose-plasma level (PL) relationship of second-generation antipsychotics, together with the treatment outcomes achieved, in seriously ill people with schizophrenia. An observational, prospective, one-year follow-up study was carried out with patients (N = 68) with severe schizophrenia treated with paliperidone three-month (PP3M) or aripiprazole one-month (ARIM). Participants were divided into standard-dose or high-dose groups. PLs were divided into "standard PL" and "high PL" (above the therapeutic reference range, TRR) groups. The dose/PL relationship, and severity, hospitalizations, tolerability, compliance, and their relationship with doses and PLs were evaluated. There was no clear linear relationship between ARIM or PP3M doses and the PLs achieved. In half of the subjects, standard doses reached PLs above the TRR. The improvements in clinical outcomes (decrease in clinical severity and relapses) were related to high PLs, without worse treatment tolerability or adherence. All participants remained in the study, regardless of dose or PL. Clinical severity and hospitalizations decreased significantly more in those patients with high PLs. Considering the non-linear dose-PL relationship of ARIM and PP3M in people with severe schizophrenia, PLs above the TRR are linked to better treatment outcomes, without worse tolerability. The need in a notable number of cases for high doses to reach those effective PLs is highlighted.

Plasmatic Levels and Response to Variable Doses of Monthly Aripiprazole and Three-Month Paliperidone in Patients with Severe Schizophrenia. Treatment Adherence, Effectiveness, Tolerability, and Safety

Introduction

There is a need when optimizing antipsychotic treatment to know the plasmatic levels (PLs) achieved with the different doses and their relationship with effectiveness and toxicity, especially in patients with poor clinical progress. This study investigates the dose-PL-response relationship of monthly aripiprazole (AOM) and three-month paliperidone (PP3M).

Methods

Observational, 52-week prospective study of patients with severe schizophrenia (CGI-S ≥ 5) treated with PP3M or AOM for at least one year before their inclusion in the study (N=68). Dose-PL relationship was determined. Subjects were included in standard-dose and high-dose (above labeled) and standard/therapeutic range-PLs and high-PLs (above range) groups. Treatment adherence, effectiveness (hospitalizations, severity), tolerability and safety were assessed. PLs and clinical response were evaluated.

Results

No clear linear relationship was found between doses and PLs. In a considerable number of cases, standard doses achieved PLs above the therapeutic range. A significant clinical improvement was related to high PLs, without less safety, tolerability, or treatment compliance being involved. Clinical severity decreased more frequently in patients who received high doses and reached high PLs. Hospital admissions decreased significantly in those patients with high PLs.

Conclusion

Taking into account the absence of a linear relationship between doses and PLs, the effectiveness in people with severe schizophrenia of AOM and PP3M depends on reaching high PLs, achieved with high doses, but also with standard doses in some cases, without leading to worse treatment tolerability, safety, or adherence.

The Use of Second-Generation Antipsychotics in Patients with Severe Schizophrenia in the Real World: The Role of the Route of Administration and Dosage-A 5-Year Follow-Up

To assess the impact of the route of administration and doses of second-generation antipsychotics (SGAs) on treatment adherence, hospital admissions, and suicidal behaviour in patients with severe schizophrenia (Clinical Global Impression−Severity−CGI-S ≥ 5), we implemented an observational 5-year follow-up study. A total of 37.5% of the patients on oral antipsychotics (Aps) and 11.5% of those on long-acting injectables (LAIs) abandoned the treatment (p < 0.001). There were no differences in treatment discontinuation between the LAI-AP standard and high-dose groups. A total of 28.1% of the patients on oral Aps had at least one hospitalisation, as well as 13.1% of patients on LAIs (p < 0.001). There were fewer hospitalisations of patients on LAIs in the high-dose group (p < 0.05). Suicide attempts were recorded for 18% of patients on oral Aps but only for 4.6% of patients on LAIs (p < 0.001). No differences were found between the dosage groups on LAIs. Tolerability was good for all Aps and somewhat better for LAIs than oral Aps in terms of side effects (p < 0.05). There were no differences between the standard and high-dose groups. More patients discontinued treatment due to side effects in the oral AP group (p < 0.01). LAI SGA treatment was more effective than oral AP in terms of adherence and treatment outcomes for managing people with severe schizophrenia. Moreover, significant improvements were found that favour high-dose LAI SGA treatment for some of these patients. This study highlights the need to consider LAI antipsychotics and high-dose strategies for patients with severe schizophrenia.

Second-Generation Antipsychotics' Effectiveness and Tolerability: A Review of Real-World Studies in Patients with Schizophrenia and Related Disorders

Despite methodological limitations, real-world studies might support clinicians by broadening the knowledge of antipsychotics' (APs) effectiveness and tolerability in different clinical scenarios and complement clinical trials. We conducted an extensive literature search in the PubMed database to evaluate the effectiveness and tolerability profiles of second-generation antipsychotics (SGAs) from real-world studies to aid clinicians and researchers in selecting the proper treatment for patients with schizophrenia and related disorders. The present review evidenced that SGAs demonstrated superior effectiveness over first-generation antipsychotics (FGAs) in relapse-free survival and psychiatric hospitalization rate and for treating negative symptoms. Persistence and adherence to therapy were higher in SGAs than FGAs. Most studies concluded that switching to long-acting injectables (LAIs) was significantly associated with a lower treatment failure rate than monotherapy with oral SGAs. Considerable improvements in general functionality, subjective well-being, and total score on global satisfaction tests, besides improved personal and social performance, were reported in some studies on patients treated with LAI SGAs. Clozapine was also associated with the lowest rates of treatment failure and greater effectiveness over the other SGAs, although with more severe side effects. Effectiveness on primary negative symptoms and cognitive deficits was rarely measured in these studies. Based on the data analyzed in the present review, new treatments are needed with better tolerability and improved effectiveness for negative, affective, and cognitive symptoms.

Effectiveness of More Personalized, Case-Managed, and Multicomponent Treatment for Patients with Severe Schizophrenia Compared to the Standard Treatment: A Ten-Year Follow-Up

Case management is a model of personalized intervention in people with severe mental illness. To explore the treatment adherence and effectiveness of patients with severe schizophrenia (Clinical Global Impression Severity, CGI-S ≥ 5) undergoing treatment in a community-based, case-managed program (CMP) with an integrated pharmacological and psychosocial approach compared with the standard treatment, an observational, ten-year follow-up study was conducted on patients treated in mental health units (MHUs) or a CMP (n = 688). Treatment discontinuation, hospitalizations, suicide attempts, and antipsychotic (AP) medications were recorded. Clinical severity was assessed with the CGI-S. Adherence to the CMP was higher than adherence to standard treatment (p < 0.001). There were fewer hospitalizations and suicide attempts in the CMP (p < 0.001). The clinical severity decreased more in the CMP (p < 0.005). Long-acting injectable (LAI) antipsychotic medication was more closely related to these outcomes than oral antipsychotics (APs) were (p < 0.001). Patients with severe schizophrenia in an integrated CMP recorded higher treatment compliance and better outcomes compared with standard care. Treatment with LAI APs was linked to these outcomes. A personalized combination of case management and LAI AP medication was more effective in these patients than standard treatment and oral APs.

Mirror image study (10 years of follow-up and 10 of standard pre-treatment) of psychiatric hospitalizations of patients with severe schizophrenia treated in a community-based, case-managed programme

OBJECTIVES

To determine the psychiatric hospitalizations of patients with severe schizophrenia before (standard treatment in mental health centres) and during treatment in a comprehensive, community-based, case-managed programme, as well as the role played by antipsychotic medication (oral or long-acting injectable).

METHODS

Observational, mirror image study of ten years of follow-up and ten retrospectives ('pre-treatment': standard), of patients with severe schizophrenia in a community-based programme, with pharmacological and psychosocial integrated treatment and intensive case management (N = 344). Reasons for discharge from the programme and psychiatric hospital admissions (and whether they were involuntary) were recorded ten years before and during treatment, as well as the antipsychotic medication prescribed.

RESULTS

The retention achieved in the programme was high: after 10 years only 12.2% of the patients were voluntary discharges vs 84.3% on previous standard treatment. The number of patients with hospital admissions, and number of admissions due to relapses decreased drastically after entering the programme (P < .0001), as well the involuntary admissions (P < .001). Being on long-acting injectable antipsychotic medication was related with these results (P < .0001).

CONCLUSIONS

Treatment of patients with severe schizophrenia in a comprehensive, community-based and case-managed programme achieved high retention rates, and was effective in drastically reducing psychiatric hospitalizations compared to the previous standard treatment in mental health units. Undergoing treatment with long-acting injectable antipsychotics was clearly linked to these outcomes.

Results from PSIPROSPER: A multicenter retrospective study to analyze the impact of treatment with paliperidone palmitate 1-month on clinical outcomes and hospital resource utilization in adult patients with schizophrenia in Portugal

BACKGROUND

Schizophrenia is a chronic psychiatric disorder with a significant impact worldwide. The early onset and its relapsing nature pose a significant challenge to patients and caregivers. The PSIPROSPER study aimed to characterize the real-world context of schizophrenia treatment in Portugal and to measure the impact of including paliperidone palmitate 1-month formulation (PP1M) in the clinical outcomes (relapses and hospitalizations) and healthcare resource utilization, in a context in which payment scheme in Portugal allows for patients to receive free antipsychotics if prescribed at public hospitals.

METHODS

This was a multicenter, retrospective, observational study. Male and female adults with a diagnosis of schizophrenia who initiated treatment with PP1M after a minimum of 12 months on an Oral Antipsychotic (OAP), and with complete medical charts, were consecutively included. A mirror-image design over 24 months allowed the comparison of outcomes before and after the PP1M introduction.

RESULTS

Out of the 51 patients included, 80.4% were male, with a mean age of 34 (±9.8) years. Around 92% of patients were being treated with PP1M at inclusion. Lack of adherence to previous OAP was the main driver for PP1M initiation. Only 9.8% of patients were hospitalized during the PP1M period vs. 64.7% during the OAP period (p < 0.0001). The mean number of hospitalizations (0.1) was significantly lower during the PP1M period (p < 0.0001). Type of treatment was the only variable found to be significant in predicting a lower hospitalization rate and a lower risk of hospitalization. Relapses were significantly lower (p < 0.0001) in PP1M (21.6%) vs. OAP (83.7%). Similarly, the mean change in the number of relapses (p < 0.0001) showed significantly better outcomes in PP1M.

CONCLUSION

This study supports PP1M as part of schizophrenia treatment in Portugal. Given the lower number of relapses and hospitalizations observed in schizophrenia patients treated with PP1M when compared to OAP-treated patients, this real-world study seems to provide further evidence to support the use of PP1M to treat this condition, in line with previous research. In the context of scarce public resources, these benefits should be carefully considered by healthcare decision-makers to ensure optimal value-based treatment strategies.

Psychosocial and Pharmacological Approaches for Improving Treatment Adherence and Outcomes in People With Severe Schizophrenia: A 10-Year Follow-up

The objective of this study was to understand the psychosocial and pharmacological approaches linked to better treatment adherence and outcomes (psychiatric hospitalizations, clinical severity, and suicide attempts) among patients with schizophrenia receiving the standard treatment in mental health units (MHUs) compared with patients in a community-based, case-managed program (CMP). An observational, prospective (10 y) study was conducted involving patients with severe schizophrenia (N=688). The treatment adherence of patients in the CMP was higher than among those in the MHUs (12.2% vs. 84.3% abandoning treatment; P<0.0001). Hospital admissions and suicide attempts were significantly lower among those treated in the CMP than among those receiving standard care in the MHUs (P<0.001). Scores on the clinical severity scale decreased significantly more in the group in the CMP than in the group in the MHUs (P<0.005). Treatment with long-acting injectable antipsychotic medication was closely linked with higher treatment retention (P<0.001) and fewer hospital admissions and suicide attempts compared with treatment with oral antipsychotics in both patient groups, with the effect greater in the group in the CMP (P<0.001). We highlight how patients with severe schizophrenia treated in a CMP with integrated treatment showed a higher retention rate, fewer psychiatric hospital admissions and suicide attempts, and less clinical severity compared with those receiving standard treatment in MHUs. Treatment with long-acting antipsychotics was also clearly related to these outcomes. A combination of intensive case-managed integrated treatment and treatment with long-acting antipsychotic medication facilitated the achievement of clinical and rehabilitation goals in patients with schizophrenia with severe symptoms and impairment compared with standard care and treatment with oral antipsychotics.

Adherence, Tolerability and Effective Doses of Aripiprazole Once-monthly in the Long-term Treatment of Patients with Severe Schizophrenia

BACKGROUND

The evaluation of long-term effectiveness and tolerability of Aripiprazole Once-monthly (AOM) is yet scarce, and severely ill patients have not been specifically studied.

OBJECTIVE

The aim of the study was to explore the long-term adherence, effectiveness and tolerability of AOM in the treatment of patients with severe (Clinical Global Impression-Severity, CGI-S ≥ 5) schizophrenia, and whether high-dose therapy may benefit patients inadequately controlled on standard doses.

METHOD

Six-year mirror-image study, with 36-month prospective follow-up, was conducted on patients with severe schizophrenia who underwent treatment with AOM (n = 60). Assessment included the CGI-S, the WHO Disability Assessment Schedule (WHO-DAS), the Medication Adherence Report Scale (MARS), laboratory tests, and weight and adverse effects reported. Reasons for treatment discontinuation, hospital admissions and psychiatric medications in the previous three years and during the follow-up were recorded.

RESULTS

The average dose was found to be 780 (120) mg/28 days. Tolerability was good, with few side effects or biological parameters alterations reported. There were three discharges due to adverse effects, two due to lack of effectiveness and one treatment abandoning. Weight and prolactin levels were found to be decreased. CGI-S and WHO-DAS decreased (p < 0.001), and MARS increased (p < 0.001). There were less treatment abandoning, hospital admissions (p < 0.0001) and concomitant medication (p<0.01) than during the previous 36 months.

CONCLUSION

Treatment adherence and tolerability of AOM were found to be remarkable, even in those patients on high doses. AOM showed effectiveness in patients with severe schizophrenia, who recorded less hospitalizations and clinical severity and disability, although a considerable percentage of them needed higher doses than labeled.

Oral Versus Long-Acting Injectable Antipsychotic Treatment for People With Severe Schizophrenia: A 5-Year Follow-up of Effectiveness

ABSTRACT

The objective here is to compare the effectiveness of long-acting injectable antipsychotics (LAI-APs) and oral ones (OAPs) in patients with severe (Global Clinical Impression-Severity ≥ 5) schizophrenia (N = 688). A 5-year follow-up study has been conducted in patients undergoing standard treatment in mental health units (MHUs) or on a severe mental illness program (SMIP). A total of 8.7% of the patients on the SMIP discontinued treatment, whereas 43.6% did so in MHUs (p < 0.0001). In both cases, treatment retention was significantly higher in patients on LAI-APs (p < 0.001). Also, hospital admissions were in both cases fewer among those on LAI-APs (p < 0.001). There was a significant link between suicide attempts and OAP treatment (p < 0.01). Given the relationship between the use of LAI-APs versus oral treatments in achieving higher adherence and less relapses and suicide attempts, the use of second-generation antipsychotics LAIs should be considered more suitable for people with severe schizophrenia.

Paliperidone Palmitate Every Three Months (PP3M) 2-Year Treatment Compliance, Effectiveness and Satisfaction Compared with Paliperidone Palmitate-Monthly (PP1M) in People with Severe Schizophrenia

Paliperidone palmitate every three months (PP3M) is expected to facilitate patient's treatment compliance and satisfaction. The objective here was to compare PP3M treatment compliance and satisfaction, effectiveness and tolerability, with paliperidone palmitate-monthly (PP1M) in patients with severe schizophrenia. A 24-month prospective, open-label study of patients with severe schizophrenia treated with PP3M after at least 2 years of stabilization with PP1M (n = 84) was carried out. Treatment satisfaction was assessed with the Treatment Satisfaction Questionnaire for Medication (TSQM) and with a Visual Analogue Scale (VAS). Effectiveness was measured with psychiatric hospital admissions and the Clinical Global Impression-Severity (CGI-S) scale. Tolerability assessments included laboratory tests, weight and adverse effects. Reasons for treatment discontinuation were recorded. CGI-S significantly improved after 24 months. Three patients changed back to PP1M due to adverse effects, and four were hospitalized. There were neither abandoning nor significant changes in weight or biological parameters, and lower incidence of side effects, with PP3M treatment. TSQM and VAS scales increased. No differences were found related to doses. Apart from somewhat improvement in treatment adherence, effectiveness, and tolerability, patients with severe schizophrenia lengthy treated with PP1M showed more satisfaction with PP3M, even those who needed high doses to get clinical stabilization.

Suicide attempts in people with schizophrenia before and after participating in an intensive case managed community program: A 20-year follow-up

Lack of treatment compliance in patients with schizophrenia is a risk factor that leads to illness-relapse, hospitalization and potentially strengthens suicidal behavior. The purpose of this investigation was to assess treatment adherence, reasons for treatment discharge, suicidal behaviour and impact of route of antipsychotics administration in a group of patients with schizophrenia treated in a comprehensive, community-based, intensive case managed program for people with severe mental illness. And to compare it to previous standard treatment received in mental health units (MHU). An observational, longitudinal, mirror-image study of patients with severe schizophrenia (N = 344) was carried out: ten years of follow-up (Program) and ten years retrospective (MHU). Reasons for treatment discharge, suicide attempts and antipsychotic (AP) medication were recorded. Treatment adherence during the Program was higher than in MHU (abandonment of treatment: 12.2% vs. 84.3% of patients). Forty patients died during follow-up, five of them due to suicide. Suicidal attempts significantly decreased during Program treatment compared to the standard one (7.6% vs. 38.9% of patients). Long-acting injectable (LAI) AP medication was significantly related to this outcome. A combination of intensive case-managed and LAIAP treatment helped to improve compliance and to reduce suicidal behavior compared to standard treatment in patients with severe schizophrenia.

Efficacy and Safety of Paliperidone Palmitate Treatment in Patients With Schizophrenia: A Real-World Multicenter, Retrospective, Mirror-Image Study

PURPOSE

The aim of the study was to assess efficacy and safety of paliperidone palmitate (PP) in schizophrenic patients using real-life data.

METHODS

This national, multicenter, retrospective, and mirror-image study was performed reviewing the medical records of patients in 18 centers. Adult schizophrenic patients receiving PP treatment (n = 205) were enrolled. Patients' data covering the last 12 months before the initial PP injection and the period until the end of study with at least 12 months after the initial PP injection were evaluated. Patients' characteristics, scale scores, and adverse events were recorded.

RESULTS

Nonadherence to prior medication was the most frequent reason for switching to PP treatment. Comparing with the period before PP treatment, the rate of patients visiting the hospital for relapse (79.5% vs 28.9%, P < 0.001) and the median number of hospitalizations (2 vs 0, P < 0.001) were lower during PP treatment. During PP treatment, the Positive and Negative Syndrome Scale score decreased by 20% or more (response to treatment) in 75.7% of the patients. The frequency of adverse events did not differ between the period before and during PP treatment. Improvement in functionality was higher in those with disease duration of 5 years or less.

CONCLUSIONS

Paliperidone palmitate is effective and safe in treatment of schizophrenic patients and in switching to PP treatment in patients with schizophrenia, which reduced the percentage of patients admitted to the hospital for relapse and the median number hospitalization, and has positive effects on functionality.

Mirror image study (10 years of follow-up and 10 of standard pre-treatment) of psychiatric hospitalizations of patients with severe schizophrenia treated in a community-based, case-managed programme

OBJECTIVES

To determine the psychiatric hospitalizations of patients with severe schizophrenia before (standard treatment in mental health centres) and during treatment in a comprehensive, community-based, case- managed programme, as well as the role played by antipsychotic medication (oral or long-acting injectable).

METHOD

Observational, mirror image study of ten years of follow-up and ten retrospectives ('pre-treatment': standard), of patients with severe schizophrenia in a community-based programme, with pharmacological and psychosocial integrated treatment and intensive case management (n=344). Reasons for discharge from the programme and psychiatric hospital admissions (and whether they were involuntary) were recorded ten years before and during treatment, as well as the antipsychotic medication prescribed.

RESULTS

The retention achieved in the programme was high: after 10 years only 12.2% of the patients were voluntary discharges vs 84.3% on previous standard treatment. The number of patients with hospital admissions, and number of admissions due to relapses decreased drastically after entering the programme (p<0,0001), as well the involuntary admissions (p<0,001). Being on long-acting injectable antipsychotic medication was related with these results (p<0,0001).

CONCLUSIONS

Treatment of patients with severe schizophrenia in a comprehensive, community-based and case-managed programme achieved high retention rates, and was effective in drastically reducing psychiatric hospitalizations compared to the previous standard treatment in mental health units. Undergoing treatment with long-acting injectable antipsychotics was clearly linked to these outcomes.

Accidental Overdose of Paliperidone Palmitate

Long-acting injectable (LAI) antipsychotics first introduced in 1960s are useful in the treatment of schizophrenic patients with poor medication adherence due to their maintaining feature of therapeutic plasma level without daily administration. Paliperidone Palmitate is one of such LAI antipsychotic drugs used due to its benefit of maintaining a therapeutic plasma level with four-week interval of injections. We report the case of a 21-year-old male with a history of mental illness that presented with selective mutism, disorganized speech, thought process and behavior, and auditory hallucinations who accidentally received 624 mg Paliperidone Palmitate intramuscularly with no reported side effects after 2 weeks of monitoring and observation. Paliperidone is a D2, 5HT2A receptor antagonist with additional antagonist activity at α-1 and α-2, H-1 receptor sites, and four metabolic pathways identified for its metabolism. Studies have reported adverse effects such as acute dystonia, acute renal failure, and cardiovascular abnormalities with Paliperidone overdose; however there is no reported literature on Paliperidone Palmitate overdose, though there have been reported cases of Paliperidone Palmitate side effects of hypersexuality and angioedema with the standard dose.

Adjunctive second-generation antipsychotics for specific symptom domains of schizophrenia resistant to clozapine: A meta-analysis

A fair amount of subjects with schizophrenia do not respond to clozapine and are defined 'ultra-resistant'. In this systematic review and meta-analysis, we tested the efficacy of adjunctive second-generation antipsychotics (SGAs) for main symptom domains (positive, negative, and depressive symptoms) in individuals with clozapine-resistant schizophrenia. We searched main electronic databases till December 2017. We included twelve double-blind, randomized, placebo-controlled trials (RCTs), evaluating the efficacy of SGAs for clozapine non/partial responders. We did not find any difference between SGAs and placebo (standardized mean difference, SMD = -0.21; p = 0.170; I² = 68.0%) in improving positive symptoms. The effect size varied according to RCT duration (p = 0.025) and assessment methods (p = 0.016). Low-moderate effects of SGAs on both negative (SMD = -0.38; p = 0.005; I² = 62.7%) and depressive symptoms (SMD = -0.35; p = 0.003; I² = 4.9%), were estimated. In sum, our meta-analysis highlights the lack of efficacy of SGAs as add-on treatment for positive symptoms in clozapine-resistant schizophrenia. A small benefit of SGAs was estimated for both negative and depressive symptoms. Further RCTs are needed to establish efficacy and tolerability of SGAs or other augmentation strategies for different symptoms of clozapine-resistant schizophrenia.