Abstract This study evaluated the effectiveness of metacognitive therapy (MCT) in the treatment of major depression. Rumination has attracted increasing interest in the past 15 years and research has demonstrated significant relationship between rumination, depression, and meta-cognition. MCT for depression is a formulation-driven treatment grounded in the Wells and Matthews‟ self-regulatory model. MCT focuses on reducing unhelpful cognitive processes and facilitates metacognitive modes of processing. MCT enables patients to interrupt rumination, reduce unhelpful self-monitoring tendencies, and establish more adaptive styles of responding to thoughts and feelings. MCT was evaluated in six-eight sessions of up to one hour each across three patients with major depressive disorder (MDD). A non-concurrent multiple-baseline with follow-up at one, six and 24 months was used. Patients were randomly allocated to different length baselines and outcomes were assessed via self-report and assessor ratings. Treatment was associated with large and clinically significant improvements in depressive symptoms, rumination and metacognitive beliefs; the gains were maintained over the follow-up
