BACKGROUND:Mindfulness-based cognitive therapy (MBCT) and maintenance antidepressant medication (mADM) both reduce the risk of relapse in recurrent depression, but their combination has not been studied. AIMS: To investigate whether MBCT with discontinuation of mADM is non-inferior to MBCT+mADM. METHOD: A multicentre randomised controlled non-inferiority trial (ClinicalTrials.gov:NCT00928980). Adults with recurrent depression in remission, using mADM for 6 months or longer (n= 249), were randomly allocated to either discontinue (n= 128) or continue (n= 121) mADM after MBCT. The primary outcome was depressive relapse/recurrence within 15 months. A confidence interval approach with a margin of 25% was used to test non-inferiority. Key secondary outcomes were time to relapse/recurrence and depression severity. RESULTS: The difference in relapse/recurrence rates exceeded the non-inferiority margin and time to relapse/recurrence was significantly shorter after discontinuation of mADM. There were only minor differences in depression severity. CONCLUSIONS: Our findings suggest an increased risk of relapse/recurrence in patients withdrawing from mADM after MBCT.