How Does the Mindfulness-Based Stress Reduction Program Achieve Its Effects on Emotional States? The Mediating Effects of Rumination Reduction and Increase in Insight

ObjectivesThis study's main goal was to test whether rumination reduction and increase in insight into one's psychological states are mechanisms through which the Mindfulness-Based Stress Reduction (MBSR) program achieves its effects on positive and negative emotional states.MethodsA quasi-experimental study was conducted on a sample of 276 CBT psychotherapy trainees, of whom 180 were in the program group (87% female, Mage = 32). Measures of mindfulness, rumination, and insight, as well as negative and positive feelings, were completed prior to and following the program.ResultsThe program was effective in increasing mindfulness (eta p2 = 0.24, 90% CI [0.17, 0.31]), reducing rumination (eta p2 = 0.11 90% CI [0.06, 0.17]) and increasing positive emotions (eta p2 = 0.09 90% CI [0.04, 0.15]), especially those relating to relaxation and warmth (eta p2 = 0.2 90% CI [0.13, 0.27]). Reduction in negative emotions was moderate (eta p2 = 0.04 90% CI [0.01, 0.09]), while insight increase approached significance (eta p2 = 0.01 90% CI [0, 0.04]). Mindfulness achieved a strong direct effect on reducing negative and increasing positive emotional states. Rumination reduction partially mediated the relationship between mindfulness and negative emotions. Rumination reduction was a stronger mediator in comparison to increase in insight, which was not significant. The model yielded a good fit (chi 2 (9, 269) = 20.529, p = 0.015, CFI = 0.984, GFI = 0.977, TLI = 0.973, RMSEA = 0.069).ConclusionsThe results suggest that the MBSR program is effective in reducing negative emotional states, and especially in increasing positive feelings of relaxation and warmth. Reducing rumination by focusing on the present is a more important mindfulness mechanism than insight.