A randomized controlled trial comparing Transdiagnostic Behavior Therapy (TBT) and behavioral activation in veterans with affective disorders

•Veterans with affective disorders were randomized to TBT or BATD.•Treatments gains were evidenced across symptoms of depression, anxiety, and PTSD.•Outcomes generally favored TBT over BATD with small effects.•Findings provide support for the movement towards transdiagnostic treatments. This randomized controlled trial (RCT) compared the efficacy of Transdiagnostic Behavior Therapy (TBT) to Behavioral Activation Treatment for Depression (BATD) in veterans diagnosed with affective disorders. TBT is a transdiagnostic psychotherapy designed to address depressive, anxiety, and post-traumatic stress disorder (PTSD) symptoms. Preliminary findings have been promising; however, no RCT has been completed to date. 105 treatment-seeking veterans were recruited and completed diagnostic and self-report measures, and then randomized into TBT or BATD treatment conditions for 12 weekly psychotherapy sessions. Assessment measures were re-administered at immediate post-treatment and 6-month follow-up. Of the 93 participants initiating treatment, 50 participants completed the full treatment protocol (TBT n = 29; BATD n = 21). No differences were observed in treatment completion across groups. Participants demonstrated significant treatment improvements across all assessments, including measures of depression, anxiety (general, cognitive, and somatic), stress, PTSD symptoms, and transdiagnostic impairment. Group differences with small effect sizes were observed in most of the studied measures, favoring TBT compared to BATD. Together, the findings support the growing literature on the efficacy of transdiagnostic psychotherapies, compared to disorder-specific treatments (DSTs). Related to the outcome findings, the benefits for transdiagnostic protocols in terms of symptom coverage, dissemination, and access were discussed.