Mediators in psychological treatment of social anxiety disorder: individual cognitive therapy compared to cognitive behavioral group therapy.

According to cognitive-behavioral models of social anxiety disorder (SAD), four of the important maintaining mechanisms are avoidance, self-focused attention, anticipatory processing and post-event cognitive processing. Individual cognitive therapy (ICT) and cognitive behavioral group therapy (CBGT) both have substantial empirical support. However, it is unclear whether they achieve their effects by similar or different mechanisms. The aim of this study was to investigate whether changes in the four maintenance processes mediate clinical improvement in ICT and CBGT for SAD. We analyzed data from participants (N = 94) who received either ICT or CBGT in two separate RCTs. The results showed that ICT had larger effects than CBGT on social anxiety and each of the four potential mediators. More pertinently, moderated mediation analyses revealed significant between-treatment differences. Whereas improvement in ICT was mainly mediated by reductions in avoidance and self-focused attention, improvement in CBGT was mediated by changes in self-focused attention and in anticipatory and post-event processing. These results support the importance of the putative mediators, but suggest that their relative weights are moderated by treatment type.