A Randomized Controlled Trial of the Effectiveness of Metacognitive Therapy (MCT) in the Treatment of Patients With Major Depressive Disorder (MDD)

Major depressive disorder is a disabling condition which adversely affects a person's family, work or school life, sleeping and eating habits, and general health.

Cognitive-behavioral therapy (CBT) is a recommended treatment for depression, with a large number of clinical trials supporting its efficacy. However, despite the success of CBT relative to other treatments, only 40-58 % of patients receiving CBT may be classified as recovered using clinical significant change assessed by the Beck Depression Inventory. Moreover, research demonstrates that only between one-third and one quarter of patients receiving CBT remain recovered at 18 months follow-up.

A new treatment approach to MDD is Meta-Cognitive Therapy. In this treatment approach, MDD is conceptualized as being maintained by rumination and meta-cognitions. Treatment seeks to challenge and change specific meta-cognitions and rumination, through behavioural experiments and verbal reattribution. No randomized controlled studies have compared the effectiveness of MCT to a waiting-list condition for MDD. Related to this, no study has examined the specific elements of therapy that are hypothesized to be of most importance for changing rumination, leading to positive treatment outcomes.

The purpose of this trial is to investigate the efficacy of Wells' MCT for Major Depressive Disorder (MDD). Another aim will be to examine the in-treatment processes associated with positive treatment outcomes.

The study will be a randomized controlled, trial comprising 50 patients with a primary diagnosis of major depressive disorder (DSM-IV; APA, 1994). Experienced diagnosticians will assess all patients by using structural interviews such as SCID-I, SCID II and the Hamilton Rating Scale for Depression.