Differential Treatment Mechanisms in Mindfulness Meditation and Progressive Muscle Relaxation

Mindfulness meditation and progressive muscle relaxation (PMR) practices are both effective in reducing stress, anxiety, and depression. To examine the mechanisms of change in mood in these two treatments, 95 participants were randomly assigned to present awareness mindfulness (PAM; N = 47) or PMR (N = 48). They were each given a 5-min audiotape of PAM or PMR and were asked to practice at least 5 min a day for 3 months. After attrition, 55 participants completed the post-intervention assessment. An additional 47 participants were assigned to a waitlist control group. Mindfulness, perceived stress, well-being, and mood symptoms were measured at pre-treatment, post-treatment, and 1-month follow-up assessment periods. PAM and PMR both led to a significant improvement in mindfulness and reduction in stress. Results of the latent growth curve analyses revealed that mindfulness and non-reactivity mediated changes in mood for PAM more than for PMR. These results suggest that differential treatment mechanisms underlie PAM and PMR.