Emotion regulation as mechanism of change in the treatment of depression - a latent change score analysis.

Deficits in emotion regulation (ER) are associated with major depressive disorder (MDD). Therefore, enhancing ER is a promising target in the treatment of MDD. In this study, we examined ER as a mechanism of change in outpatient, group-based ER-focused psychotherapy for MDD, conducting secondary analysis of randomized controlled trial (RCT) data. Depressive symptom severity (DSS) and ER were assessed five times during an 8-week Affect Regulation Training (N = 73). Firstly, we tested cross-sectional correlations of ER and DSS at all assessment points. Then, we employed latent growth curve modeling (LGCM) to explore associations between changes in ER and DSS during treatment. Finally, we applied bivariate latent change score modeling (LCS) to test whether improvements in ER skills predicted subsequent reductions in DSS. Cross-sectional analyses revealed negative correlations between ER and DSS at all time points. Longitudinal LGCM analyses showed that an increase in ER skills during treatment was associated with a decrease in DSS. Finally, LCS analyses indicated that changes in ER predicted subsequent changes in DSS, whereas the reverse relationship was not significant. These finding support a causal relationship between the enhancement of ER skills and subsequent reduction of DSS, highlighting the importance of ER as a mechanism of change in the treatment of depression. Future research should extend these analyses to other disorders beyond depression to further clarify the role of ER as a critical transdiagnostic factor and a promising treatment target for a wide range of mental health conditions. The original RCT was registered at ClinicalTrials.gov, Nr. NCT01330485.