Effects of an imagery-enhanced behavioral activation intervention on depressive symptoms and activation levels: Results from the WIMBA-trial

Psychological treatments for depression are effective but about half of the patients do not improve in treatment suggesting a need for treatment innovation. Evidence-based treatments, such as Behavioral Activation (BA), aim to increase rewarding activities in daily life. Lab-based research has shown that by generating mental imagery of potentially rewarding activities (rather than thinking about them verbally) individuals can alter their appraisals of these activities, increasing anticipated pleasure and motivation. However, BA does not explicitly encourage patients to use mental imagery when scheduling activities. The present randomized controlled parallel two-arm trial tested a novel imagery-enhanced BA intervention (Web-based Imagery Behavioral Activation or WIMBA) delivered online in a sample of N = 168 adults from Germany fulfilling diagnostic criteria for a major depressive episode. Participants were randomized 1:1 to four brief, unguided online WIMBA sessions or to a wait-list control condition (without active treatment components). WIMBA comprised four weekly sessions including psychoeducation, imagery-enhanced activity scheduling, and personalized feedback. Primary outcome measures were the Behavioral Activation for Depression Scale - Short Form and the Beck Depression Inventory-II. Intention-to-treat analyses showed significantly higher increases in behavioral activation for WIMBA compared to wait-list from session 3 which sustained through follow-up (baseline to follow-up increase of 9.4, d = 1.0). Depressive symptoms decreased significantly more after WIMBA (baseline to follow-up decrease of 9.3, d = 1.1). Dropout data and participant feedback support good acceptability and feasibility of WIMBA. Unguided web-delivered imagery-enhanced BA offers promise for scalability and further trials, including an active control, are warranted. Trial preregistration: https://osf.io/97wuf.