Postpartum depression (PPD) affects 13 % of new mothers and 5-13 % of fathers, influencing family dynamics and child development. This systematic review evaluates the efficacy of psychological interventions in preventing PPD among expectant parents, highlighting the role of early, preventive psychological therapies. We conducted a systematic search across the databases: CINAHL, Cochrane Library, Embase, PsykINFO, Web of Science, and PubMed, identifying studies published in English that met our inclusion criteria: (1) randomized controlled trials
(2) interventions focusing on psychological therapies such as psychoeducation, psychosocial support, and cognitive-behavioral strategies
(3) targeting expectant mothers and co-parents without severe depressive symptoms
and (4) measuring outcomes with validated tools. Quality was assessed using the Risk of Bias 2 tool, and data synthesis was performed descriptively due to the heterogeneity of interventions. From 5319 articles screened, 25 studies were included, encompassing a variety of intervention strategies and participant demographics. Psychological interventions significantly reduced PPD incidence in half the studies. Interventions included psychoeducation, mindfulness exercises, internet-based and interpersonal cognitive behavioral therapies, with longer intervention durations and low-risk participant profiles showing the most notable benefits. The studies collectively emphasized the potential of early intervention during pregnancy to prevent PPD. Psychological interventions in expectant parents can significantly lower the risk of developing PPD, with benefits extending to family dynamics and child development. The diversity of effective strategies supports tailored approaches based on individual risk profiles and preferences. Future research should focus on broadening participant demographics, incorporating longitudinal designs, and enhancing methodological rigor to refine prevention strategies further.