ObjectivesEvidence suggests the efficacy of mindfulness-based cognitive therapy (MBCT) to prevent depression relapse and decrease depressive symptoms during the acute phase. However, the effectiveness of MBCT in real-world heterogeneous samples treated in clinical health settings, including primary care, has received little attention. This study had two aims: (1) to evaluate the effectiveness of MBCT delivered in primary care considering pre-treatment depression scores and (2) to explore the role of participants’ characteristics on symptom improvement.MethodsData were obtained from 433 individuals who received MBCT. Participants completed the Personality Inventory for ICD-11 (PiCD) pretreatment and the Beck Depression Inventory (BDI-II) pre- and post-treatment.ResultsSixty percent presented moderate-to-severe depression according to scores on the BDI-II, 18.1% presented mild depression, and 21.7% were in the non-depressed range. The severity of pre-treatment depressive symptoms was associated with outcomes. Most individuals who lacked depressive symptoms at baseline remained in the non-clinical range after the treatment. Those in the severe group benefited the most from the intervention, since 35.6% were considered recovered. Rates of deterioration ranged from 2.1 to 2.7%, depending on the depression-baseline scores. Depression severity at the entrance, attendance, and age, but not personality traits, appear to be related to symptom improvement.ConclusionsAccording to our results, MBCT can be effectively and safely delivered in primary care.