Monitoring and Acceptance, or Monitoring Only? Effects of a Dismantled Mindfulness Intervention on Mindfulness and Emotional Outcomes: A Randomized Controlled Trial.

INTRODUCTION: Previous studies based on the Monitoring and Acceptance Theory (MAT) failed to find differential effects of monitoring plus acceptance (MA) and monitoring only (MO) training on negative affect. This study aimed to investigate the differences between MA and MO from the perspective of mindfulness and emotional outcomes. METHODS: A total of 392 participants were randomly assigned to three groups (MA, MO, or Waiting-List [WL]). MA or MO participants received a 14-day online mindfulness training focused on monitoring and acceptance skills, or only monitoring skills, respectively. We used the Five Facet Mindfulness Questionnaire, the Positive and Negative Affect Scale, and the Emotional Reactivity Scale (ERS) assess the outcomes before the intervention (T1), after the intervention (T2), and at the 2-week follow up (T3). Linear mixed model (LMM) was conducted to explore the data based on intent-to-treat (ITT) and per-protocol (PP) analyses. RESULTS: Both the MA and MO groups demonstrated significant improvements in the total mindfulness score and positive affect compared to the WL group (p < 0.05). A significant Group × Time interaction was observed for ERS; however, post hoc tests revealed no significant between-group differences. Negative affect did not differ significantly across groups (p > 0.05). No significant differences between MA and MO were observed for any outcome (p > 0.05). DISCUSSION: This study demonstrated that MA and MO had equivalent effects on mindfulness and emotional outcomes following a 2-week online training program.