Abstract
BACKGROUND: Exposure-based CBT is highly effective in treating patients with panic disorder and agoraphobia; however, access to such treatments is often limited. Smartphone-based self-management apps offer a promising low-threshold treatment alternative to face-to-face therapy. Although such health apps have shown to be effective in reducing anxiety symptoms, comparisons to active treatments are still scarce. Therefore, this study compared the effectiveness of a self-help app to an established face-to-face CBT intervention for panic and agoraphobia. METHOD: The present study conducts a post hoc comparison of two independent RCTs examining participants with panic disorder and/or agoraphobia. Interventions in both studies were based on the same CBT manual. Study 1 (n = 138) included face-to-face CBT; Study 2 addressed the effects of a digital self-help intervention (n = 57). Main outcomes comprised symptoms of both panic disorder and agoraphobia, depressive symptoms and agoraphobic avoidance. Data were analysed using linear mixed models in intent-to-treat and completer data sets. RESULTS: Linear mixed models showed that face-to-face treatment was superior to app treatment in reducing panic and agoraphobic symptoms (R(2) = 0.32), depressive symptoms (R(2) = 0.24) and agoraphobic avoidance (R(2) = 0.12 and 0.15). Dropout rates did not differ significantly, and both interventions demonstrated high levels of adherence. DISCUSSION: Although a smartphone-based CBT intervention was effective in reducing symptoms of panic and agoraphobia, its efficacy was significantly below the effects of the same intervention delivered in face-to-face format. Thus, digital interventions might be most suitable within a stepped-care approach or to bridge waiting times for psychotherapy.