Cost and Outcome of Behavioural Activation versus Cognitive Behavioural Therapy for Depression (COBRA) : a randomised, controlled, non-inferiority trial

BACKGROUND: Depression is a common, debilitating, and costly disorder. Many patients request psychological therapy, but the best-evidenced therapy-cognitive behavioural therapy (CBT)-is complex and costly. A simpler therapy-behavioural activation (BA)-might be as effective and cheaper than is CBT. We aimed to establish the clinical efficacy and cost-effectiveness of BA compared with CBT for adults with depression. METHODS: In this randomised, controlled, non-inferiority trial, we recruited adults aged 18 years or older meeting Diagnostic and Statistical Manual of Mental Disorders IV criteria for major depressive disorder from primary care and psychological therapy services in Devon, Durham, and Leeds (UK). We excluded people who were receiving psychological therapy, were alcohol or drug dependent, were acutely suicidal or had attempted suicide in the previous 2 months, or were cognitively impaired, or who had bipolar disorder or psychosis or psychotic symptoms. We randomly assigned participants (1:1) remotely using computer-generated allocation (minimisation used; stratified by depression severity [Patient Health Questionnaire 9 (PHQ-9) score of