Abstract Background The co-occurrence of psychotic disorders and borderline personality disorder (BPD) complicates clinical management, with overlapping symptoms exacerbating morbidity and impairing therapeutic outcomes. This systematic review and meta-analysis aimed to estimate the prevalence of psychotic disorders and BPD co-occurrence, including with first-episode psychosis (FEP) and to describe associated sociodemographic and clinical characteristics. Methods Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, four databases were systematically searched from inception to June 2025. Eighteen studies met the inclusion criteria. Data extraction and quality appraisal (Effective Public Health Practice Project tool) were conducted independently by two reviewers. Random-effects meta-analyses estimated pooled prevalence rates. Results The pooled prevalence of BPD in people with psychotic disorders was 22.7% (95% CI: 14.2–34.3%), while 14.3% (95% CI: 5.5–32.1%) of individuals with BPD had a comorbid psychotic disorder. In FEP samples, 40.0% (95% CI: 21.9–61.3%) met the criteria for BPD. People with both conditions, often young women, showed greater emotional dysregulation, suicidality, psychotic symptoms, and social dysfunction. Trauma, dissociation and substance use emerged as frequent vulnerability factors. However, most studies were cross-sectional, with small samples and high heterogeneity ( I 2 > 80%), limiting generalizability. Conclusion This co-occurrence constitutes a distinct clinical subgroup with complex needs. Categorical diagnostic approaches may fail to capture the dimensional nature of overlapping affective and psychotic symptoms. Integrative and personalized care pathways, especially in early intervention settings, are warranted. This review was registered in PROSPERO (CRD42024577525).
Jourdan et al. (Thu,) studied this question.