"Intellect", a Mobile Health Application based on cognitive-behavioral therapy principles, improves Anxiety and Worry: A Randomized Controlled Trial with an Active Control and a 2-Week Follow-Up

Digital self-guided mobile health (mHealth) applications are cost-effective, accessible, and well-suited to improve mental health at scale. This randomized controlled trial (RCT) evaluated the effectiveness of a recently developed mHealth programme based on cognitive-behavioral therapy (CBT) principles in improving worry. We also examined psychological mindedness (PM) as a mediator by which app engagement is thought to improve outcomes. The intervention group completed a 2-week "Anxiety and Worry" programme with daily CBT-informed activities, while the active waitlist-control completed a matched 2-week mHealth programme on procrastination. Participants filled out the Generalized Anxiety Disorder (GAD-7), Patient Health Questionnaire (PHQ-9), and Psychological Mindedness Scale (PMS) at baseline, post-intervention and 2-week follow-up. App engagement was measured at post-intervention only. Both groups showed significant improvements on anxiety and depression scores from baseline to post-intervention, but no group differences were observed. From post-intervention to follow-up, only the intervention group showed further improvements for anxiety levels. Higher engagement with the mHealth app reported lower anxiety at post-intervention, and this relationship was fully mediated by psychological mindedness. This study provides evidence that (a) engaging in a CBT mHealth App can effectively reduce anxiety and worry, and (b) Psychological mindedness is a potential pathway by which engaging with a mHealthapp improves worry. While overall effect sizes were small, at the population level, these can make significant contributions to public mental health. Author SummaryIncreasing burden of anxiety amongst young adults has made widely accessible mobile health applications a promising tool in improving anxiety levels at scale. We conducted a randomized controlled trial (N=309) to examine the effectiveness of a brief, publicly available mobile health application (Intellects "Anxiety and Worry" programme) in reducing anxiety and worry levels among young adults. Participants who received the intervention showed significant reduction in anxiety and depression levels, however, effects did not significantly differ from active control. At post-intervention, only the intervention group continued to experience improvements in anxiety level. We also found that higher app engagement with the mHealth app predicted better anxiety and depression outcomes, and this relationship was fully mediated by psychological mindedness. Future work would benefit from inclusion of waitlist control, a larger sample size, and identification of alternative mediators.