Abstract
BACKGROUND: Previous studies have indicated that higher subjective well-being works as a protective factor for health. Some studies have already shown the effects of mindfulness-based interventions on improving subjective well-being. However, these studies targeted specific populations rather than the general public. Furthermore, they assessed either life evaluation or affective aspects of subjective well-being rather than the concept as a whole, including the eudemonic aspect of well-being. OBJECTIVE: This study aims to investigate the effectiveness and cost-effectiveness of mindfulness-based cognitive therapy (MBCT) for improving the wholistic aspects of subjective well-being in healthy individuals. METHODS: This study was an 8-week, randomized, parallel-group, superiority trial with a 2-month follow-up. Healthy individuals aged 20-65 years with scores lower than 25 on the Satisfaction With Life Scale (SWLS) were eligible to participate and randomly allocated to the MBCT group or the wait-list control group. The intervention program was developed by modifying an MBCT program to improve the well-being of a nonclinical population. The primary outcome was the difference between the two groups in mean change scores from the baseline on the SWLS. The secondary outcomes included scores on the Flourishing Scale and the Scale of Positive and Negative Experience as well as the incremental cost-effectiveness ratio. RESULTS: This study began recruiting participants in July 2018 and recruitment was completed at the end of September 2019. Data collection and dataset construction was completed by the end of March 2020. CONCLUSIONS: This study is unique in that it investigates MBCT's effects on the three different aspects of subjective well-being: life evaluation, affect, and eudemonia. It is limited, as the specific effect attributable to MBCT cannot be detected because of the lack of an active control group. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) UMIN000031885; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000036376. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/15892.