The COMET study: Metacognitive Therapy and Cognitive Behaviour Therapy for Depression

INTERVENTION: Participants will be randomised to receive 12 weeks of individual therapy;either Metacognitive therapy(MCT) or cognitive behaviour therapy (CBT). Most participants will receive 12 sessions in 12 weeks with 6 sessions in the first 4 weeks however the range permissible is 8 to 15 sessions over the 12 weeks. Therapy sessions last up to 1 hr. Clinical psychologists deliver both therapies and follow the work of AT Beck and J Beck for CBT(1,2) and of Adrian Wells and Costas Papageorgiou for MCT (3,4). References 1. Beck AT, Rush AJ, Shaw BF, Emery G. Cognitive therapy of depression. Guildford Press, New York,1979. 2. Beck JS. Cognitive therapy: basics and beyond. The Guilford Press, New York, 1995. 3. Wells A. Metacognitive Therapy for Anxiety and Depression The Guilford Press; 2009. 4. Papageorgiou C, Wells A, eds. Depressive rumination: nature, theory and treatment. John Wiley, West Sussex, England, 2004. CONDITION: Major depressive disorder PRIMARY OUTCOME: Early change measured by percent change in brain activation on fMRI in the dorso‐lateral prefrontal cortex and amygdala regions Reduction in depressive symptoms at end treatment measured by change in the Quick Inventory of Depressive Symptomatology (QIDS‐C‐16 item) (rated by an independent rater) Speed of early change measured by reduction in Quick Inventory of Depressive Symptomatology scores (QIDS‐C‐16 item) (rated by an independent rater) SECONDARY OUTCOME: Improved emotional processing, measured by the Recognition of posed facial expressions task Improvement in executive functioning, measured by the Rapid Visual Information Processing (CANTAB) Reduction in depressive rumination, measured by the Response Styles Questionnaire‐ rumination subscale Reduction in maladaptive metacognitions measured by the Metacognitions‐30 scale Reduction in self‐report depressive symptoms at end treatment rated by the Quick Inventory of Depressive Symptomatology‐ self report (QIDS‐ SR) Time to achieve non‐depressed status over the course of treatment measured by the Quick Inventory of Depressive Symptomatology‐ self report (QIDS‐ SR) (survival curve, QIDS‐SR<6). INCLUSION CRITERIA: Current major depressive disorder (DSM‐IV) Able to complete questionnaires and psychotherapy in the english language.