Therapist adherence to interpersonal vs. supportive therapy for social anxiety disorder.

We assessed therapist adherence to interpersonal therapy (IPT) and supportive therapy (ST) in a controlled trial for social anxiety disorder. Raters blindly scored n = 133 videotapes from 53 participants using the Collaborative Study Psychotherapy Rating Scale (CSPRS). Results reveal statistical differences across groups, but higher than expected overlap. Greater use of IPT in beginning sessions predicted better outcome in both therapies. Suboptimal adherence may be due to the crossed design in which the same therapists delivered both IPT and ST. Since switching between different approaches is a clinical reality for integrative psychotherapists, these findings may have important clinical implications.