Abstract
BACKGROUND: This systematic review evaluates specialized psychosocial and complex interventions for early bipolar disorder (BD), early borderline personality disorder (BPD), early depression, early psychosis, and first-episode mental illness in general (FEMI). METHODS: We included systematic reviews and randomized controlled trials (RCTs) of interventions with psychosocial components, excluding trials that focused on pharmacological-only interventions and stand-alone psychotherapies. Searches were conducted in January 2023 across five databases. Review quality was assessed using AMSTAR-2 and risk of bias for RCTs using the Cochrane tool. RESULTS: Ten studies met the inclusion criteria: seven reviews and three RCTs. High-to moderate-quality evidence supports complex psychosocial interventions combined with pharmacotherapy for early psychosis. The most robust effects were reductions in relapse and improvements in psychosocial functioning; additional benefits were observed for symptom burden, remission, treatment discontinuation, and hospital admissions. Benefits were most sustained in longer-duration, community-based programs. For early BD, limited evidence suggests that combining pharmacotherapy with family-focused therapy or structured psychoeducation may improve the course of illness and treatment satisfaction. One RCT in early BPD reported improved engagement with a developmentally tailored program. Two FEMI RCTs found that nurse-led psychoeducation and psychosocial programs improved in-patient duration, symptoms, insight, self-efficacy, quality of life, and engagement. No eligible studies addressed early-stage depression, indicating a notable evidence gap for multimodal psychosocial interventions. CONCLUSIONS: Complex psychosocial interventions are strongly supported for early psychosis. Preliminary data in BD, BPD, and FEMI suggest consistent benefits for engagement, but further rigorous trials - especially in early depression - focusing on different outcomes - are required.