About half of patients with depression who complete the UK National Health Service Talking Therapies stepped care pathway still have symptoms. A randomized trial tested whether adding mindfulness-based cognitive therapy (MBCT) via videoconference to treatment as usual improves outcomes for these patients. At 34 weeks, the MBCT group had significantly lower depression scores than the treatment-as-usual group (adjusted difference -2.49 points on the PHQ-9). The MBCT group also had slightly lower healthcare costs and higher quality-of-life scores, with a 99% chance of being cost-effective at the £20,000 per QALY threshold. No serious adverse events occurred. MBCT is an effective and scalable further-line treatment for depression that does not remit after psychological therapy.
For adults with difficult-to-treat depression—those who have not responded to prior treatments, have treatment-resistant depression, or have a chronic course—mindfulness-based cognitive therapy (MBCT) is likely superior to usual care, reducing depressive symptoms by a standardized mean difference of -0.40 at post-treatment and -0.41 at medium-term follow-up. There was a 92% and 85% probability, respectively, that these benefits exceeded a minimal important difference. However, MBCT did not show clear superiority over other active psychosocial interventions, and no robust moderators of outcome were identified across baseline severity, chronicity, or comorbidity.
Mindfulness-based cognitive therapy (MBCT) plus treatment as usual leads to greater symptom improvement than treatment as usual alone in adults with difficult-to-treat depression who have not remitted after high-intensity psychological therapy. The therapy works partly by increasing decentering—the ability to observe thoughts and feelings as temporary mental events—and this mechanism remains effective even when depressive symptoms are severe. Higher baseline depression severity does not limit the acquisition of decentering skills or the overall treatment effect; instead, decentering is more strongly linked to symptom reduction in those with more severe depression. These findings support using MBCT across a broad range of symptom severity.