The majority of mindfulness research to date has reported only on the group-level effects of interventions. Therefore, there is a need to better understand who is most likely to benefit from mindfulness interventions. This study reports on moderation analyses from a two-centre randomised controlled trial of mindfulness-based stress reduction (MBSR) among 288 medical and psychology students. The study investigated whether baseline personality factors (neuroticism, conscientiousness and extroversion) and baseline mindfulness moderated effects on mental distress, study stress and subjective well-being measured after the intervention. An increased effect of the intervention on mental distress and subjective well-being was found in students with higher scores on neuroticism. Students with higher scores on conscientiousness showed an increased effect of mindfulness training on study stress. The training protected students against an increase in mental distress and study stress and a decrease in subjective well-being that was seen in the control group. Baseline mindfulness and extroversion did not moderate the effects of the intervention on the outcomes. The majority of the 288 medical and psychology students in the study sample were female. Female participants scored significantly higher on neuroticism and conscientiousness, and they may therefore be an important target group for mindfulness interventions among students.
Keywords: MBSR; Mindfulness; Moderation; Personality; RCT; Students.