Comparative effectiveness of mindfulness and physical exercise on rumination in patients with major depression: An integrated evaluation of an open label randomized trial

Background and aims: Rumination, characterized by repetitive and prolonged negative thoughts, is a common symptom of Major Depressive Disorder (MDD) that can impair treatment effectiveness. Among MDD treatments, pharmacological and non-pharmacological approaches have been demonstrating important changes in brain and behavior. Therefore, this randomized controlled trial aimed to evaluate the level of rumination of individuals who underwent the combined use of escitalopram and physical exercise or mindfulness practice, compared to those who used the medication as a stand-alone. Methods: Rumination was evaluated in 88 MDD patients who were randomly assigned to three groups: stand-alone pharmacotherapy (control group, CG, n = 33), escitalopram adjunct to exercise (exercise group, EG, n = 26, 2 h/week), and escitalopram adjunct to mindfulness (mindfulness group, MG, n = 29, 2 h/week), in a 12-week treatment. The Ruminative Response Scale-Short Form (RRS-SF) was administered pre- and post-treatment to assess changes in rumination levels. Results: While all groups exhibited reductions in general rumination, the mindfulness group demonstrated larger effect sizes (MG: d = 1.30; EG: d = 0.68; CG: d = 0.96), particularly among patients with high baseline rumination levels (MG: d = 1.51; EG: d = 0.88; CG: d = 0.42). Results for patients with low baseline levels of rumination were mixed. Further analysis of the reflective factor of the RRS-SF showed reductions only for EG and MG. A greater reduction in the brooding factor was found for MG in patients with high level of rumination. Conclusion: These findings suggest that mindfulness, when used as a complementary therapy, may reduce the burden of MDD by promoting a more resilient state of mind that fosters less ruminative thought patterns, particularly in patients with intense rumination.