Mobile App-Guided Exposure Therapy for Panic Disorder With and Without Agoraphobia: Randomized Controlled Trial.

Background: Mobile apps that implement disorder-specific psychotherapy for panic disorder (PD) with and without agoraphobia can be used in real-life situations that trigger symptoms and, therefore, are a promising novel therapeutic tool. Objective: This randomized controlled trial aimed to expand the currently limited evidence base for the efficacy of mobile interventions for PD with and without agoraphobia by evaluating a mobile app focusing on interoceptive and in-vivo exposure therapy. Methods: After establishing the diagnosis of PD with and without agoraphobia using a secure video communication platform, we randomized 111 adults to 3 equally sized groups: disorder-specific exposure therapy app, mindfulness meditation app unrelated to the disorder (active control condition), and waiting list (passive control condition). Participants used the apps in a self-guided manner. Additional psychotherapy was not allowed during the study. Self-reported PD with and without agoraphobia symptom severity was our primary outcome parameter and measured by the Panic and Agoraphobia Scale and symptom subset scales. Secondary outcome parameters included depressive symptoms and quality of life. We conducted assessments at baseline, after the intervention (allocation+5 wk), and at follow-up (allocation+13 wk). Results: We observed significantly lower overall PD with and without agoraphobia symptom severity in the exposure app group compared to waiting list post-treatment (P=.04, Cohen d=0.55) and at follow-up (P=.04, Cohen d=0.60). At follow-up, the exposure app group demonstrated significantly stronger improvements than the waiting list group in depressive symptoms (P=.007, Cohen d=0.75) and psychological quality of life (P=.01, Cohen d=0.63). We observed no significant differences between the exposure and the meditation apps in overall PD with and without agoraphobia symptom severity (post-treatment: P>.99, follow-up: P=.84). In the exposure app group, 35% (n=11) of participants showed reliable improvement in overall PD with and without agoraphobia symptom severity at post-treatment (meditation app: n=2, 6%; waiting list: n=2, 7%; P=.002). The dropout rate after 5 weeks was 14% (5/37) in the exposure app group (meditation app: 3/37, 8%; waiting list: 6/37, 16%; P=.68). No adverse outcomes were reported in the exposure app group. Conclusions: Our findings suggest that app-guided exposure therapy can be a useful further treatment option in addition to established psychological and pharmacological strategies. However, superiority compared to the disorder-unspecific meditation app remains unclear.