The Long-Term Effects of Mindfulness-Based Cognitive Therapy as a Relapse Prevention Treatment for Major Depressive Disorder.

Background: Mindfulness-based Cognitive Therapy (MBCT) is a relapse prevention treatment for major depressive disorder. Method: An observational clinical audit of 39 participants explored the long-term effects of MBCT using standardized measures of depression (BDI-II), rumination (RSS), and mindfulness (MAAS). Results: MBCT was associated with statistically significant reductions in depression from pre to post treatment. Gains were maintained over time (Group 1, 1-12 months, p = .002; Group 2, 13-24 months, p = .001; Group 3, 25-34 months, p = .04). Depression scores in Group 3 did begin to worsen, yet were still within the mild range of the BDI-II. Treatment variables such as attendance at \"booster\" sessions and ongoing mindfulness practice correlated with better depression outcomes (p = .003 and p = .03 respectively). There was a strong negative correlation between rumination and mindful attention (p < .001), consistent with a proposed mechanism of metacognition in the efficacy of MBCT. Conclusion: It is suggested that ongoing MBCT skills and practice may be important for relapse prevention over the longer term. Larger randomized studies of the mechanisms of MBCT with longer follow-up periods are recommended.