A Pilot Study Comparing the Efficacy of Traditional Buddhist Mindfulness Training Versus Secular Mindfulness-based Cognitive Therapy for Patients Having Residual Depressive Symptoms

This study has the following objectives: 1. To investigate whether traditional Buddhist mindfulness training is non-inferior to secular MBCT in reducing depressive symptoms and improving psychological wellbeing (primary outcomes) 2. To compare the effectiveness of the two interventions on self-compassion, mindfulness, and spirituality/religiosity (secondary outcomes) 3. To investigate whether self-compassion, mindfulness, and spirituality/religiosity mediate the effectiveness of the interventions 4. To investigate whether baseline spirituality/religiosity moderates the effectiveness of the interventions 5. To compare the effectiveness of the two interventions in preventing depressive relapse over 6 months and 12 months. This will be a parallel group, randomized controlled trial conducted at Colombo North Teaching Hospital (CNTH), and the Faculty of Medicine, University of Kelaniya and involves interventions conducted over 4 months, followed by 12 months of follow-up. Patients with a history of depressive disorder will be recruited from the Psychiatry Clinic, Colombo North Teaching Hospital. Sample size, calculated for a non-inferiority trial design, is 30 in each group. Simple randomization and allocation concealment using sequentially numbered, opaque, sealed envelopes will be used. Both groups will undergo interventions over 8 weeks, with weekly 2-hour sessions. One group will undergo the novel intervention, i.e., traditional Buddhist mindfulness training. The other group will undergo MBCT. Primary outcomes will be depressive symptom severity (Beck Depression Inventory-II), Psychological wellbeing (WHO-5 Wellbeing Index), and the depressive relapse rate at 6 months and 1 year after completion of intervention. Secondary outcomes include mindfulness (Six-Facet Mindfulness Questionnaire), Self-compassion (Self-compassion scale - short form), Spirituality/religiosity (BENEFIT scale), and Acceptability/feasibility. To establish non-inferiority, the 95% CI of the mean difference will be compared against the non-inferiority margin. Moderator and mediation analyses will be conducted.