A randomised controlled trial to investigate the clinical effectiveness and cost effectiveness of Mindfulness-Based Cognitive Therapy (MBCT) for depressed non-responders to Increasing Access to Psychological Therapies (IAPT) high-intensity therapies: study protocol - Barnhofer, Thorsten; Dunn, Barnaby D.; Strauss, Clara; Ruths, Florian; Barrett, Barbara; Ryan, Mary; Ladwa, Asha; Stafford, Frances; Fichera, Roberta; Baber, Hannah; McGuinness, Ailis; Metcalfe, Isabella; et al. (Trials, 2023)