The alliance mediates outcome in cognitive-behavioral therapy for social anxiety disorder, but not in attention bias modification.

The aim of the current study was to examine changes in the therapeutic alliance and its role as a mediator of treatment outcome in cognitive behavioral therapy (CBT) for social anxiety disorder (SAD) compared to attention bias modification (ABM). Patients were randomized to 16-20 sessions of CBT (n = 33) or 8 sessions of ABM (n = 17). Patient-rated alliance and self-reported social anxiety were measured weekly and evaluator-rated social anxiety was measured monthly. Early alliance predicted greater subsequent anxiety reduction in CBT but not in ABM. The alliance increased and weekly improvements in alliance predicted weekly contemporaneous and subsequent decreases in anxiety only in CBT. Decreases in anxiety did not predict subsequent improvements in alliance. Both treatments were effective in reducing anxiety, but treatment effects were mediated by stronger early alliance and stronger cross-lagged effects of alliance on outcome in CBT compared to ABM. The results highlight the importance of the alliance in CBT for SAD. Further studies should examine the role of alliance alongside additional mediators to better understand differential mechanisms in CBT and ABM.