Behavioral Activation for Depression and Glycemic Control in Type 2 Diabetes: A Systematic Review and Meta-Analysis.

Depression in type 2 diabetes mellitus (T2DM) hinders self-management and glycemic control. Behavioral activation (BA), by increasing participation in positive activities, holds promise for simultaneously improving depressive symptoms and diabetes outcomes. This study evaluated the effects of BA or BA-based interventions on depressive symptoms, glycated hemoglobin (HbA1c), diabetes self-efficacy, and self-management behaviors in adults with T2DM, and summarized their implementation characteristics. PubMed, Web of Science, Embase, Cochrane Library, PsycINFO, CNKI, VIP, and Wanfang Data were searched from inception to February 1, 2026. Interventional studies assessing BA or BA-based interventions in adults with T2DM and reporting at least one prespecified outcome were included. Quantitative meta-analyses were restricted to randomized controlled trials (RCTs) and conducted using random-effects models. Implementation characteristics from all included studies were narratively synthesized. Six studies involving 252 participants met the inclusion criteria, including five RCTs and one single-arm pre-post study. The meta-analysis suggested a reduction in depressive symptoms (SMD = -0.81, 95% CI: -1.22 to -0.41, p < 0.001), but no statistically significant effects on HbA1c (MD = -0.04%, 95% CI: -0.30 to 0.22, p = 0.76), diabetes self-efficacy (SMD = 0.03, 95% CI: -0.30 to 0.35, p = 0.87), or self-management behaviors (SMD = 0.04, 95% CI: -0.23 to 0.32, p = 0.77). Narrative synthesis indicated that BA interventions varied in delivery format, dosage, provider background, and integration with diabetes-specific content. Most interventions were delivered by non-mental health professionals and incorporated core BA components such as activity monitoring and goal setting. BA may reduce depressive symptoms in adults with T2DM, whereas its effects on glycemic control, diabetes self-efficacy, and self-management behaviors remain uncertain. BA has been delivered in flexible formats and may have potential for integration into diabetes care, but larger, well-powered RCTs with longer follow-up are needed to determine whether diabetes-specific BA can improve behavioral and physiological outcomes.