Disorder-specific internet-based cognitive-behavioral therapy in treating panic disorder, comorbid symptoms and improving quality of life: A meta-analytic evaluation of randomized controlled trials.

Compared to conventional face-to-face psychological treatments, internet-based cognitive-behavioral therapy (iCBT) presents an innovative alternative that has been found to be effective in the treatment of anxiety disorders. The current study provides a meta-analysis investigating the efficacy of disorder-specific guided self-help (Gsh) iCBT compared to various active and inactive control conditions, with focus on adult panic disorder sufferers with or without agoraphobia (PD/A). Systematic literature search yielded 13 randomized controlled trials (RCTs) (N = 1214) that met the eligibility criteria for this study. We found no statistically significant differences between Gsh iCBT and various active CBT interventions in reducing PD/A symptoms at both post-test (g = 0.015, k = 10) and follow-up (g = 0.113, k = 6) levels. Also, comorbid anxiety and depression were reduced equivalently at post-test (g = 0.004, k = 6) and follow-up (g = 0.004, k = 6). Quality of life was equally improved at post-test (g = -0.100, k = 5) and follow-up (g = 0.074, k = 2). When compared to inactive controls, we found large effect sizes in PD/A (g = -0.892, k = 9) and comorbid anxiety and depression (g = -0.723, k = 9) symptoms, and moderate change in quality of life (g = -0.484, k = 3) at post-test. There was no difference between Guided self-help iCBT and Self-help iCBT in PD/A (g = -0.025, k = 3) and comorbid anxiety and depression (g = -0.025, k = 3) at post-test. Baseline severity, country of original research and adherence to the treatment in form of initial uptake were identified as statistically significant moderators of the iCBT treatment.