ABSTRACT
Objectives: To determine the prevalence and correlates of treatment-resistant schizophrenia (TRS) through a systematic review and meta-analysis. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria, an electronic search was performed in PubMed and Embase through May 17, 2022. All study designs that assessed a minimum of 20 schizophrenia-spectrum patients and provided data on TRS prevalence or allowed its calculation were included. Estimates were produced using a random-effects model meta-analysis. Results: The TRS prevalence across 50 studies (n = 29,390) was 36.7% (95%CI 33.1-40.5, p < 0.0001). The prevalence ranged from 22% (95%CI 18.4-25.8) in first-episode to 39.5% (95%CI 32.2-47.0) in multiple-episode samples (Q = 18.27, p < 0.0001). Primary treatment resistance, defined as no response from the first episode, was 23.6% (95%CI 20.5-26.8) vs. 9.3% (95%CI 6.8-12.2) for later-onset/secondary (≥ 6 months after initial treatment response). Longer illness duration and recruitment from long-term hospitals or clozapine clinics were associated with higher prevalence estimates. In meta-regression analyses, older age and poor functioning predicted greater TRS. When including only studies with lower bias risk, the TRS prevalence was 28.4%. Conclusion: Different study designs and recruitment strategies accounted for most of the observed heterogeneity in TRS prevalence rates. The results point to early-onset and later-onset TRS as two separate disease pathways requiring clinical attention. Registration number: PROSPERO CRD42018092033.
ABSTRACT
Abstract Background Despite of its global underuse, clozapine is still the golden standard antipsychotic for patients with treatment-resistant schizophrenia (TRS). Objective To evaluate the patterns of clozapine and other antipsychotic drugs prescription in TRS in community mental health centers in São Paulo, Brazil. Methods A multiple-choice questionnaire was applied to fifteen psychiatrists at five centers inquiring about patients’ clinical condition, adherence to oral treatment and current antipsychotic treatment. History of previous and current antipsychotic treatment was collected through medical chart review. Results Out of 442 schizophrenia patients, 103 (23.3%) fulfilled the criteria for TRS. Fifty-eight patients (56.3%) were receiving polypharmacy; 30 (29.1%) were on atypical antipsychotic monotherapy, 14 (13.6%) were on typical antipsychotic monotherapy, 25 (24.3%) were taking depot antipsychotic medication and only 22 (21.4%) were receiving clozapine. Discussion As well as in other parts of the world, many TRS patients (78.6%) receive other drugs instead of clozapine in São Paulo, the best evidence-based medication for patients with TRS. The government should make every effort to provide medical training and the equipment and logistic support to adequately serve those who could benefit from clozapine treatment at the community health centers.