Effectiveness of Mindfulness-Based Cognitive Therapy for Improving Subjective and Eudaimonic Well-Being in Healthy Individuals: A Randomized Controlled Trial

Objectives: Better subjective and eudaimonic well-being fosters better health conditions. Several studies have confirmed that mindfulness-based interventions are effective for improving well-being; however, the samples examined in these studies have been limited to specific populations, and the studies only measured certain aspects of well-being rather than the entire construct. Additionally, few studies have examined the effect of mindfulness-based cognitive therapy on well-being. The present study examines the feasibility of mindfulness-based cognitive therapy and its effectiveness for improving subjective and eudaimonic well-being among community residents. Methods: The study design featured an 8-week randomized, waiting-list controlled, parallel-group study. 8 weekly mindfulness classes, followed by 2 monthly classes, were provided for healthy individuals aged 20-65 years who had a Satisfaction with Life Scale score of ≤ 24 indicating average to low cognitive aspect of subjective well-being. This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry (ID: UMIN000031885, URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000036376). Results: The results showed that cognitive aspect of subjective well-being and mindfulness skills were significantly improved at 8 weeks, and this effect was enhanced up to the end of the follow-up period. Positive affective aspect of subjective and eudaimonic well-being were significantly improved at 16 weeks. Conclusions: Eight weeks of mindfulness-based cognitive therapy with a 2-month follow-up period improves cognitive and affective aspects of subjective and eudaimonic well-being in healthy individuals. The order of improvement was cognitive, positive affective, and eudaimonic well-being. To verify these findings, multi-center randomized controlled trials with active control groups and longer follow-up periods are warranted.