Which emotion regulation strategies are mediating the outcome of acceptance and commitment therapy compared to cognitive-behaviour therapy in the treatment of anxiety symptoms?

OBJECTIVE

To examine multiple emotion regulation strategies as mediators in ACT compared to CBT for anxiety. It was hypothesized that augmenting acceptance and reducing suppression, distraction, and perseverative thinking would mediate the effect of ACT compared to CBT. Cognitive reappraisal was included as a competitive mediator.

METHOD: Data were collected as part of a randomized controlled trial comparing ACT and CBT in a sample of 314 older adults with anxiety symptomatology. Participants filled in self-report questionnaires assessing anxiety symptom severity (Generalized Anxiety Disorder-2) and the putative mediators a total of five times over the course of treatment. Latent growth curve models, parallel process models, random intercept-cross lagged panel models, and autoregressive latent trajectory models were used to model the hypothesized prospective and mediational relationship.

RESULTS

ACT differentially affected acceptance, suppression, and distraction, and changes in all mediators (except acceptance) showed significant cross-sectional associations with outcome. Only cognitive reappraisal predicted subsequent anxiety levels and vice versa, irrespective of treatment. However, none of the emotion regulation variables mediated the effect of ACT.

CONCLUSIONS

The discrepancy with previous positive findings on emotion regulation as a mediator may be attributed to earlier studies not using a longitudinal design and analysis on the within-person level.