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.

Objective: There is growing evidence supporting the association between migration and posttraumatic stress disorder (PTSD). Considering the growing population of migrants and the particularities of providing culturally sensitive mental health care for these persons, clinicians should be kept up to date with the latest information regarding this topic. The objective of this study was to critically review the literature regarding migration, trauma and PTSD, and mental health services. Methods: The PubMed, SciELO, LILACS, and ISI Web of Science databases were searched for articles published in Portuguese, English, Spanish, or French, and indexed from inception to 2017. The following keywords were used: migration, mental health, mental health services, stress, posttraumatic stress disorder, and trauma. Results: Migration is associated with specific stressors, mainly related to the migratory experience and to the necessary process of acculturation occurring in adaptation to the host country. These major stressors have potential consequences in many areas, including mental health. The prevalence of PTSD among migrants is very high (47%), especially among refugees, who experience it at nearly twice the rate of migrant workers. Conclusions: Mental health professionals must be trained to recognize and provide appropriate care for posttraumatic and/or stress-related disorders among migrants.