The Unified Protocol for Transdiagnostic Treatment of Emotional Disorders compared with diagnosis-specific protocols for anxiety disorders: A three-year follow-up.

OBJECTIVE

Compare the long-term efficacy of diagnosis-specific and transdiagnostic cognitive-behavioral therapies (CBT) from a randomized equivalence trial for the treatment of heterogenous anxiety disorders.

METHOD: Participants were treatment completers (N = 80; 58.8% female) from the parent equivalence trial treated with either the Unified Protocol (UP; n = 44) or the single-disorder CBT protocol (SDP; n = 36) for their primary anxiety disorder. Clinical interviews were conducted at 24- and 36-month follow-up and self-report questionnaire batteries were completed at 18-, 24-, 30-, and 36-month follow-up. With-in condition effect sizes were calculated to determine maintenance of treatment gains in each treatment condition over time and potential differences between treatment conditions were evaluated using the principal diagnosis clinician severity rating (CSR) from the Anxiety Disorder Interview Schedule (ADIS); additional outcomes included anxiety, depression, and functional impairment.

RESULTS

Treatment gains within each condition were largely maintained at three years post-treatment, with small fluctuations in subclinical symptoms. At 36-month follow-up, the UP and SDP treatment conditions remained comparable on the principal diagnosis ADIS CSR. Although there were some differences on secondary outcomes favoring the SDP condition at intermediate time points, there were no significant differences between the UP and SDP conditions on ADIS CSR or any secondary outcomes at 36-month follow-up.

CONCLUSIONS

Results further support the utility of the UP as a single intervention that produces durable treatment effects for the most commonly occurring psychological disorders through demonstration of outcomes commensurate with current first-line SDPs.