Web-Based Imagery Behavioral Activation (WIMBA): Study Protocol for a Randomized Controlled Trial Testing the Effects, Acceptability, and Feasibility of a Mental Imagery Activity Scheduling Training Delivered Online

Behavioral activation (BA) is an effective and efficacious treatment for depression. Activity scheduling is the central treatment component of BA and involves planning of potentially enjoyable and rewarding activities. Evidence from non-clinical studies suggests that mental imagery simulations of planned activities can increase motivation and anticipated pleasure for these activities. We describe a randomized controlled trial testing a mental imagery activity scheduling training delivered online in four weekly sessions (total training duration approximately 90 minutes) in a sample meeting diagnostic criteria of a major depressive episode, as indicated by the Diagnostic Short-Interview for Mental Disorders (Mini-DIPS), and not currently receiving treatment. Participants (N = 140) will be randomized to either mental imagery activity scheduling or a wait-list control condition. Depressive symptoms (BDI-II) and behavioral activation (BADS) are the primary outcomes; BDI-II will be measured at Session 1, Session 4, and at two-week follow-up, BADS at Sessions 1-4 and at two-week follow-up. It is discussed how the expected results may reflect mechanisms and effects of a mental imagery activity scheduling training delivered online in a sample of individuals with depression. Concluding we outline next steps for future research and highlight the potential of this novel treatment for dissemination in the wider community and integration into routine care.