Effectiveness of interventions in the prevention of mood disorders: an overview of systematic reviews with meta-analysis

Introduction: Mood disorders are highly prevalent conditions associated with substantial clinical, social, and economic burden worldwide. Despite this impact, evidence-based guidance on preventive interventions remains limited, particularly regarding strategies to prevent disease onset and recurrence. Objective: To assess the effectiveness of preventive interventions for depressive and bipolar disorders through an overview of systematic reviews with meta-analyses. Methods: This overview followed the PRISMA guidelines and was prospectively registered in PROSPERO (CRD42022323580). Systematic reviews with meta-analyses published between 2010 and 2021 were identified in SciELO, LILACS, MEDLINE/PubMed, and the Cochrane Database of Systematic Reviews. Reviews addressing primary, secondary, or tertiary prevention of mood disorders were included. Methodological quality was assessed using AMSTAR-2. Results: Twenty-four systematic reviews met the inclusion criteria. For primary prevention, evidence was available exclusively for depressive disorder, showing that psychological and psychosocial interventions, such as cognitive-behavioral therapy, interpersonal therapy, psychoeducation, mindfulness-based programs, and family-focused interventions, were associated with a reduced incidence of depressive episodes in at-risk populations, including children, adolescents, adults, perinatal women, and post-stroke patients. Secondary and tertiary prevention studies primarily addressed relapse and recurrence. In major depressive disorder, both psychological interventions and pharmacological maintenance treatments significantly reduced relapse risk, with combined approaches often yielding superior outcomes. In bipolar disorder, maintenance pharmacotherapy with mood stabilizers and second-generation antipsychotics, as well as structured psychoeducational interventions, demonstrated efficacy in preventing mood episode recurrence. However, most reviews were rated as low or critically low methodological quality, reflecting heterogeneity, limited longitudinal data, and small sample sizes. Conclusions: Preventive interventions for mood disorders, particularly psychological, psychosocial, and maintenance pharmacological strategies, demonstrate consistent effectiveness in reducing incidence and recurrence across diverse populations. Although the overall evidence is constrained by methodological limitations, the findings support current international guideline recommendations and highlight prevention as a critical component of mental health care. Strengthening preventive psychiatry through robust research and integration into public health policies may substantially reduce the long-term burden of mood disorders.