Introduction
major depression, anxiety, depressive disorder, depressive symptoms, depression
REMISSION
Major depressive disorder, a highly prevalent mental health condition characterized by persistent negative mood and loss of pleasure, is linked to significantly decreased quality of life and poses a major societal burden [Telehealth interventions present especially attractive options for alleviating such mental health disparities [Among the various forms of telehealth interventions, asynchronous message-based psychotherapy holds particular promise, as it is more likely to be accessible through mobile apps and is met with less skepticism as a means of intervention [Previous studies have demonstrated that asynchronous message-based psychotherapy is acceptable and feasible for treating various mental health conditions, including major depression [Asynchronous message-based psychotherapy also appears to be efficacious in improving depressive symptoms. The results of a pilot study assessing message-based asynchronous psychotherapy treatment over 12-16 weeks demonstrated that patients reported significantly less life distress following 3.9 months of treatment, with 46% experiencing clinically significant symptom remission [Although existing research shows potential for treating major depression through asynchronous message-based psychotherapy, the need for further randomized controlled trials remains. The purpose of this study was to evaluate whether asynchronous message-based psychotherapy is clinically effective and acceptable for treating major depression when compared to weekly video-based psychotherapy (a standard practice) in a randomized controlled trial. Treatment efficacy was measured by changes in depression, anxiety, and functional impairment, and acceptability by treatment credibility and expectancy, therapeutic alliance, and engagement. It was hypothesized that both the treatment efficacy and acceptability of asynchronous message-based psychotherapy would be noninferior to those of video-based psychotherapy. That is, reductions in depression, anxiety, and functional impairment in the message-based condition would not be significantly smaller than those in the video-based condition. Similarly, levels of treatment credibility and expectancy, therapeutic alliance, and engagement in the message-based condition would not be significantly lower than those in the video-based condition.