The role of self-acceptance, negative mood regulation, and ruminative brooding on mindfulness and depressive symptoms: A longitudinal, randomized controlled trial of mindfulness meditation vs. relaxation training

Date of Completion

January 2008


Psychology, Clinical




Depression is a significant mental health risk in student populations. Mindfulness-based interventions have gained increasing support for improving mood and reducing depressive symptoms. This study of approximately 83% White college students proposed (1) a theoretical model of mindfulness meditation and depressive symptoms with self-acceptance, negative mood regulation, positive affect, and ruminative brooding as hypothesized mechanisms; and (2) a longitudinal randomized trial with an active control that dismantles the mindfulness meditation (MM) component of mindfulness-based interventions and compares it with relaxation training (RT). Findings from Study 1 (n = 514) using a Structural Equation Modeling (SEM), indicate that mindfulness, as measured by the Freiburg Mindfulness Inventory (FMI), was statistically significantly related to self-acceptance, negative mood regulation, and positive affect while indirectly and inversely related to ruminative brooding and depressive symptoms as measured by the CES-D. Study 2 (n = 120) consisted of students screened for depressive symptoms who were randomly assigned to either an MM (n = 61) or an RT (n = 59) group and instructed to listen to a 20-minute guided CD three times a week for four weeks. Participants were assessed at four time points: at baseline, 5, 12, and 24 weeks. Using a Hierarchical Linear Modeling (HLM), results indicate that both groups improved significantly on depressive symptoms. There were statistically significant Time X Group differences for mindfulness and self-acceptance with the Time X Group differences in negative mood regulation approaching significance. Both groups experienced a significant decrease in ruminative brooding. Analyses of mediation indicate that self-acceptance, negative mood regulation and ruminative brooding mediate the effects of mindfulness on depressive symptoms, with negative mood regulation providing full mediation. This study provides a powerful examination of the effects of mindfulness on depressive symptoms. It is also of practical relevance in supporting the effectiveness of a stand-alone MM training in decreasing depressive symptoms. Findings from this study contribute to the ongoing dialogue on mindfulness meditation by proposing a model of mindfulness and depression and by isolating mindfulness as a key component of mindfulness-based interventions in precipitating improvement in psychological outcomes. ^