A randomized controlled trial of mindfulness-based cognitive therapy for major depressive disorder in undergraduate students: Dose- response effect, inflammatory markers and BDNF

•Dose-response effect.•MBCT and MDD.•Inflammatory markers and BDNF. To examine the dose-response effect of mindfulness-based cognitive therapy (MBCT) for college students with major depressive disorder (MDD), a randomized control trial with MBCT and a wait-list (WL) group was performed. All participants were invited to self-administer a set of questionnaires at baseline, mid-intervention (4th week), and post-intervention (8th week) by the 9-item Patient Health Questionnaire (PHQ-9), the 7-item Generalized Anxiety Disorder scale (GAD-7), the Pittsburgh Sleep Quality Index (PSQI), the Five Facet Mindfulness Questionnaire (FFMQ), the Self-Compassion Scale (SCS). The serum levels of IL-1β, IL-6, IL-8, TNF-α, BDNF were detected at baseline and post-intervention. After intervention, the scores of PHQ-9, GAD-7, PSQI, and the levels of IL-1β, IL-6, IL-8 and TNF-α in the MBCT were significantly lower than those in WL group, and total scores of FFMQ, SCS, and the level of BDNF were significantly higher than those in WL group. In MBCT group, daily practice time and session numbers positively related to reduction rates of PHQ-9, GAD-7 and PSQI at post-intervention. The reduction rate of PHQ-9, GAD-7 and PSQI at post-intervention in the completers were higher significantly than those in the partial attendees. These findings suggested MBCT is effective for MDD, and the intervention has a dose-response effect. Registration number is [ChiCTR2100044309].