This study evaluated changes in positive affect within cognitive-behavioral treatments (CBT) for anxiety disorders. It was hypothesized that there would be significantly greater increases in positive affect in CBT conditions compared to the waitlist, and particularly higher in the Unified Protocol (UP) than the single disorder protocols (SDP) given the UP's focus on emotions (including positive emotions) rather than symptoms.

Patients with heterogeneous anxiety disorders (N = 223) were randomly assigned to the UP, SDP or waitlist. Linear mixed model regression (intent to treat) analyses were used to compare change in positive affect, quality of life, and savoring between patients in the treatment conditions (UP and SDP) versus waitlist conditions. Between condition effect sizes were calculated to assess the magnitude of difference within conditions at post-treatment.

Results indicated a significant Group (treatment vs. waitlist) × Time (pre- post-treatment) interaction (F(1, 154.36) = 6.75; p = .01) for positive affect in which the treatment group showed significant improvements in positive affect pre- to post-treatment (ESsg = 0.37, SEsg = 0.09, 95% CI [0.20: 0.54]) and the waitlist condition did not. There were no differences between UP and SDP conditions in positive affect at baseline or at post-treatment.

These results suggest CBT, which typically focuses on reductions in negative affect, may also improve positive affect. The importance of future research evaluating, targeting, and improving positive affect in CBT trials is discussed.

Clinicaltrials.gov Identifier: NCT01243606