Family-based psychosocial interventions and social functioning in schizophrenia: a retrospective cohort study of caregiver–patient dyadic outcomes

Background The effectiveness of family-based psychosocial interventions (FPIs) in schizophrenia, particularly regarding dose – response patterns and caregiver – patient dynamics, remains insufficiently understood. This study examined how varying levels of real-world FPI exposure relate to social functioning in adults diagnosed with schizophrenia.Methods A retrospective cohort of 812 Chinese adults diagnosed with schizophrenia treated at a psychiatric hospital was analyzed. Participants were categorized by documented FPI exposure from none to high (≥5 sessions). The primary outcome was change in social functioning measured by the Personal and Social Performance Scale (PSP). Secondary outcomes included caregiver burden and patient – caregiver associations. Multivariable regression models adjusted for demographic and clinical covariates.Results Higher FPI exposure was associated with greater PSP improvement (p < 0.001). In adjusted models, greater FPI intensity remained associated with improved functioning (β = 0.28, p < 0.001) and reduced caregiver burden (β = −0.28, p < 0.001). Lower caregiver burden at follow-up was also associated with better patient functioning (β = −0.25, p < 0.001). High-exposure participants were more likely to achieve clinically meaningful improvement (aOR = 2.11, 95% CI: 1.41–3.16).Discussion Greater FPI exposure was associated with clinically meaningful functional gains, suggesting a potential threshold effect. Findings should be interpreted cautiously given the observational design but support sustained family involvement in routine care.