Objectives: Clinician-supported internet-delivered cognitive behavioral therapy (ICBT) can be an effective treatment option when treating social anxiety disorder (SAD). Unguided ICBT is often found to be less effective. One possible solution to reduce the costs of clinician support is to provide support on demand. In this format of guidance, participants have the option to contact their clinician if needed. In a few studies, this mode of support has been compared favorably to scheduled support.

Method: Participants in a previously reported controlled trial on SAD who had been in a waitlist control group were randomly allocated to ICBT with either on-demand guidance or scheduled weekly therapist guidance. A total of 99 participants were included. Data were collected weekly on the primary outcome measure, the Liebowitz Social Anxiety Scale self-report (LSAS-SR), and at pre- and post-treatment for secondary measures. Data were analyzed in accordance with the intention-to-treat principle using mixed-effects models.

Results: Both groups improved significantly during the treatment according to the LSAS-SR ratings. The groups did not differ in their estimated change during the treatment period, with a between-group effect of d = 0.02, 95% CI [-0.37, 0.43]. Both groups experienced similar improvement also on the secondary outcome measures, with small between-group effect sizes on all outcomes.

Conclusions: The findings indicate that support on demand can be an effective way of providing guidance in ICBT for SAD, although more research on this topic is needed. A limitation of the study is that it was conducted in 2009, and the findings were in the file drawer. Subsequent published studies support our initial findings, but more research is needed.