Long-term efficacy of Metacognitive Training for Depression (D-MCT): A randomized controlled trial

The availability of treatment for depression needs to be improved. Among the barriers are the dearth of group programmes and the high demand of many programmes with regard to staff expertise. The Metacognitive Training for Depression (D-MCT) is a new, easy-to-administer, cognitive behaviour-based group intervention. In a previous 6-month trial, D-MCT was highly accepted by patients and efficacious compared to a control treatment. The aim of the current study was to examine whether the effects of the D-MCT can be sustained over 3.5 years.

Long-term follow-up of a randomized controlled trial.

A total of 84 patients with a confirmed diagnosis of unipolar depressive disorder were enrolled in a randomized, controlled, assessor-blind, parallel group trial comparing two interventions added to usual care: D-MCT and general health training (HT). Patients were reassessed 3.5 years after the interventions were terminated. Primary outcome was the Hamilton Depression Rating Scale. Self-assessed depressive symptom severity (BDI), dysfunctional cognitive (DAS) and metacognitive (MCQ) beliefs, self-esteem (RSE), and quality of life (WHOQOL-BREF) served as secondary outcomes.

Primary intention-to-treat analyses using analysis of covariance showed negative results, and only secondary post-hoc analyses utilizing latent growth modelling demonstrated superiority of D-MCT over HT with regard to the long-term course of depressive symptom severity and cognitive and metacognitive outcomes as well as physical and psychological quality of life.

Findings suggest that D-MCT may be a promising add-on treatment for unipolar depression that should be investigated in large multi-centre studies. Independent replications are needed.

Clinical implications: The current study shows tentative evidence that positive effects of the D-MCT reported at the 6-month follow-up assessment were sustained over 3.5 years. Potential positive effects regard severity of depression, dysfunctional cognitive, and metacognitive beliefs as well as quality of life. If positive results are replicated with less trained therapists, D-MCT offers the possibility of providing a simple and easy-to-administer CBT-based group treatment for depression with long lasting effects.

Sample size was small; a large-scale multi-centre trial would be desirable to gain high statistical power with an adequate sample size and to allow the investigation of possible allegiance effects. D-MCT was delivered as an add-on intervention and not as a stand-alone intervention.