Brief Web-based Intervention for Depression: A Randomized Controlled Trial on Behavior Activation (STRONG-study) (Preprint)

BACKGROUND: Web-based interventions have been shown to be effective for the treatment of depression. However, interventions are often complex and include a variety of elements, making it difficult to identify the most effective component(s). OBJECTIVE: The aim of this pilot study was to shed light on mechanisms in the online treatment of depression by comparing a single-module, fully automated intervention for depression (internet-based behavioral activation [iBA]) to a nonoverlapping active control intervention and a nonactive control group. METHODS: We assessed 104 people with at least mild depressive symptoms (Patient Health Questionnaire-9, >4) via the internet at baseline (t0) and 2 weeks (t1) and 4 weeks (t2) later. After the t0 assessment, participants were randomly allocated to one of three groups: (1) iBA (n=37), (2) active control using a brief internet-based mindfulness intervention (iMBI, n=32), or (3) care as usual (CAU, n=35). The primary outcome was improvement in depressive symptoms, as measured using the Patient Health Questionnaire-9. Secondary parameters included changes in activity, dysfunctional attitudes, and quality of life. RESULTS: While groups did not differ regarding the change in depression from t0 to t1 (etap(2)=.007, P=.746) or t0 to t2 (etap(2)=.008, P=.735), iBA was associated with a larger decrease in dysfunctional attitudes from t0 to t2 in comparison to CAU (etap(2)=.053, P=.04) and a larger increase in activity from t0 to t1 than the pooled control groups (etap(2)=.060, P=.02). A change in depression from t0 to t2 was mediated by a change in activity from t0 to t1. At t1, 22% (6/27) of the participants in the iBA group and 12% (3/25) of the participants in the iMBI group indicated that they did not use the intervention. CONCLUSIONS: Although we did not find support for the short-term efficacy of the single-module iBA regarding depression, long-term effects are still conceivable, potentially initiated by changes in secondary outcomes. Future studies should use a longer intervention and follow-up interval. TRIAL REGISTRATION: DKRS (#DRKS00011562).