Intensive 7-day internet-delivered cognitive behavioural therapy for social anxiety disorder: A randomized controlled trial

This is the first randomised controlled trial (RCT) to examine the efficacy of intensive internet-delivered CBT (iCBT) for social anxiety disorder (SAD). Adults (mean age: 44.77 years, 75.4 % female) diagnosed with SAD were randomly allocated to iCBT (n = 33) or a waitlist control group (WLC; n = 28). The iCBT group received a clinician-guided, six lesson program delivered online over seven days. Participants completed self-report measures of social anxiety and depression symptoms, and functional impairment at two- (post-treatment) and six-weeks post-baseline (one-month follow-up), and a diagnostic interview to assess SAD and major depressive disorder (MDD) at baseline and one-month follow-up. The iCBT group reported significantly lower social anxiety symptoms (Hedges' g's > .96), and functional impairment at post and one-month follow-up (g's > .59), but there were no significant differences in depression symptoms (g's = .42). Participants in the iCBT group were less likely to continue to meet criteria for SAD (47.6 %) at follow-up compared to WLC (96.4 %). Adherence (83.9 % completion) and program satisfaction (85.2 % reported being 'mostly' or 'very satisfied') were promising. Delivering iCBT over an intensive treatment period is feasible and acceptable to participants with SAD and showed promise for reducing social anxiety and functional impairment. Further research is needed to compare intensive iCBT with active control groups, using a larger and more diverse sample and longer-term outcomes.