(PS8-C66) Change in Aversive Reactivity to Emotions Predicts Decreases in Symptoms After Treatment Termination

The question of when to discontinue treatment is important for both clinicians and treatment researchers. As improvement in putative mechanisms of action may precede symptom change during treatment, change in mechanisms could be used to trigger decisions regarding when to end treatment. One psychological process that has been proposed to maintain symptoms is aversive reactivity to emotional experiences. We used a sequential multiple assignment randomized trial (SMART) adaptive treatment design to examine whether change in this mechanism of action during treatment can serve as an indicator of later treatment response, thus indicating when treatment can be ended. Seventy outpatients with transdiagnostic emotional disorders completed up to 12 sessions of the Unified Protocol (UP), which includes five core skill modules designed to reduce aversive reactivity to emotions. Patients underwent two stages of randomization. In the first-stage randomization, patients were assigned at baseline to receive the core UP modules in an order that prioritized their personal strengths, deficits, or the standard published order. In the second-stage randomization, patients were assigned to either discontinue care at session six (brief treatment) or receive the remaining six sessions (full treatment). The second-stage randomization enabled us to examine whether the degree of mechanism engagement during the first six sessions could predict maintenance or continued symptom improvement for patients who ended treatment after six sessions. To do this, we estimated separate latent intercept and slope factors for anxiety and depression scores across the first- and second-stage randomizations, as well as a latent intercept and slope factor for aversive reactivity scores across the first-stage randomization. We then regressed the latent second-stage anxiety scores on latent first-stage intercepts and slopes of aversive reactivity and second stage anxiety intercepts, including first-stage sequencing condition as a covariate. We repeated this model with depression scores. Steeper decreases in aversive reactivity during sessions 1-6 predicted continued steeper decreases in anxiety during weeks 7-12, regardless of whether patients continued treatment, b = .51, SE = .23, p = .03, 95% CI [.06, .97]. In addition, lower aversive reactivity at week seven predicted steeper decreases in depression during weeks 7-12 for patients in both conditions, b = .51, SE = .17, p < .01, 95% CI [.18, .84]. Using the intercept of depression slopes across weeks 7-12 (a = –.66, SE = .38, p = .09), patients with aversive reactivity scores of 34.63 or lower would be likely to demonstrate continued decrease in depression across weeks 7-12. This result suggests that initial level, level at session seven, and change in aversive reactivity during treatment may serve as predictors of subsequent change in anxiety and depression after six sessions of treatment, regardless of whether treatment is continued. This information may benefit clinicians in that more than six sessions may be unnecessary for some patients, as they are likely to continue to improve in the absence of treatment.