Examining a Fully Automated Mobile-Based BehavioralActivation Intervention in Depression: RandomizedControlled Trial

Background: Despite significant progress in our understanding of depression, prevalence rates have substantially increased inrecent years. Thus, there is an imperative need for more cost-effective and scalable mental health treatment options, includingdigital interventions that minimize therapist burden.Objective: This study focuses on a fully automated digital implementation of behavioral activation (BA)-a core behavioralcomponent of cognitive behavioral therapy for depression. We examine the efficacy of a 1-month fully automated SMS textmessage-based BA intervention for reducing depressive symptoms and anhedonia.Methods: To this end, adults reporting at least moderate current depressive symptoms (8-item Patient Health Questionnairescore >= 10) were recruited online across the United States and randomized to one of three conditions: enjoyable activities(ie, BA), healthy activities (ie, an active control condition), and passive control (ie, no contact). Participants randomizedto enjoyable and healthy activities received daily SMS text messages prompting them to complete 2 activities per day;participants also provided a daily report on the number and enjoyment of activities completed the prior day.Results: A total of 126 adults (mean age 32.46, SD 7.41 years) with current moderate depressive symptoms (mean score16.53, SD 3.90) were recruited. Participants in the enjoyable activities condition (BA; n=39) experienced significantly greaterreductions in depressive symptoms compared to participants in the passive condition (n=46). Participants in both activeconditions-enjoyable activities and healthy activities (n=41)-reported reduced symptoms of anxiety compared to those inthe control condition.Conclusions: These findings provide preliminary evidence regarding the efficacy of a fully automated digital BA interventionfor depression and anxiety symptoms. Moreover, reminders to complete healthy activities may be a promising intervention forreducing anxiety symptoms.