Effectiveness of Behavioral Activation in Treating Thai Older Adults with Subthreshold Depression Residing in the Community

Background In recent years, behavioral activation (BA) has attracted increased interest as an effective depression treatment. However, empirical evidence supporting its effectiveness in non-Western countries is currently limited. Objective To examine the effectiveness of BA in reducing depressive symptoms, stress, and anxiety among Thai older adults with subthreshold depression. Methods and Subjects A clustered randomized controlled trial was conducted in two health promoting hospitals (HPHs) in the Samut Songkhram province of Thailand. One hospital was used for the intervention (BA+usual care group) and the other for the control (usual care-only group). Each HPH randomly selected 41 eligible older adults residing in their jurisdictions to take part in the study. Mental health outcomes were assessed using the Thai Geriatric Depression Scale (TGDS) and Depression Anxiety Stress Scales (DASS). The BA effectiveness was evaluated using generalized estimating equations (GEE) at a group level and the reliable change index (RCI) at the individual level. Results Over 9 months, the adjusted mean change in depression (TGDS) scores [−2.47 (95% CI: −3.84, −1.00)], mental health status (DASS), specifically depression and stress score [−1.47 and −1.87 (95% CI: −2.43, −0.50 and −2.94, −0.79, respectively)], improved significantly in the BA+usual care group compared to the usual care-only group, whereas anxiety score improved significantly only at 6 months [−0.87 (95% CI: −1.52, −0.23)]. Additional RCI analysis showed that BA was directly associated with 14.63 to 24.39% points increase in the reliable improvement of depressive outcome compared to the usual care-only group. Conclusion This study showed that the BA effectively improved depression, stress, and anxiety in older adults with subthreshold depression in a Thai community setting. Future research should evaluate the longer-term effectiveness of BA in diverse population groups.