A randomized clinical trial of transdiagnostic cognitve-behavioral treatments for anxiety disorder by comparison to relaxation training.

Transdiagnostic cognitive-behavioral treatments (CBT) for anxiety disorders have been gaining increased attention and empirical study in recent years. Despite this, all of the research on transdiagnostic anxiety treatments to date have either not used a control condition, or have relied on no-treatment or delayed-treatment controls, thus limiting inferences about comparative efficacy. The current study was a randomized clinical trial examining the efficacy of a 12-week transdiagnostic cognitive-behavioral group treatment in comparison to a 12-week comprehensive relaxation training program. Results from 87 treatment initiators suggested significant and statistically equivalent/noninferior outcomes across conditions, although relaxation was associated with a greater rate of dropout despite no differences in treatment credibility. No evidence was found for any differential effects of transdiagnostic CBT for any primary or comorbid diagnoses.