Predictors and Session-Specific Effects of Metacognitive Training for Depression (D-MCT)

Cognitive biases contribute to symptoms of depression in both its primary diagnosis and comorbid expressions. Exploring the module-specific effects of Metacognitive Training for Depression (D-MCT) in patients with comorbid depression offers valuable insights into how the various D-MCT modules address shared mechanisms, paving the way for a better understanding of how it works for these patients.

Participants with primarily comorbid depression were recruited on a specialized ward for OCD and anxiety-related disorders (N = 108). The study investigated the session-specific effects of each module of the D-MCT by linear mixed effect models (i) over the course of the intervention, (ii) within each session, and (iii) between sessions. Secondly, a Lasso regression analysis was performed to examine whether changes in cognitive biases in specific modules would predict overall change in depressive symptoms of the D-MCT.

The results indicated small effects for the change in beliefs about rumination (d = 0.49) and mind reading (d = 0.24) over the time of the intervention. Within-session analyses revealed several session-specific effects, including a change in maladaptive beliefs about rumination within the module on this topic, with a medium effect size (d = 0.67). The Lasso regression indicated the change in negative filter as a predictor for the change in depressive symptoms, but this was not confirmed by a subsequent linear regression analysis.

The results suggest that patients with comorbid depression might benefit from special emphasis on themes such as rumination that bridge the primary and comorbid diagnoses in groups with a high prevalence of OCD and an anxiety-related disorder.