Does a lifestyle-based intervention improve sleep quality in individuals with major depressive disorder? A randomized controlled trial

Abstract Objective: Major depressive disorder (MDD) is a leading cause of global disability, contributing to substantial individual, social, and economic burdens. While antidepressant therapy remains the cornerstone of treatment, complementary lifestyle-based interventions, such as multimodal exercise and mindfulness, have shown promise in alleviating mood symptoms. However, their specific impact on sleep quality, a critical therapeutic target in MDD, remains underexplored. Methods: In a 12-week randomized controlled trial, 88 patients with MDD were assigned to three groups: pharmacotherapy alone (control group - CG), pharmacotherapy plus home-based multimodal exercise (exercise group - EG), or pharmacotherapy plus home-based mindfulness training (mindfulness group - MF). Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI) at baseline, week 5, and week 12. Results: A linear mixed-model (LMM) was performed, and significant group-by-time interactions were observed. At baseline, the EG exhibited lower PSQI scores compared to the MF (p = 0.002, d = 0.75) and CG (p = 0.001, d = 0.83). At week 5, the EG continued to show superior sleep quality relative to mindfulness (p = 0.018, d = 0.64) and CG (p = 0.001, d = 0.89). At week 12, the MF also demonstrated better sleep quality than the CG (p = 0.002, d = 0.80). All groups improved over time, with exercise yielding rapid benefits and MF showing progressive, sustained improvements. Conclusion: Lifestyle-based interventions enhance sleep quality in MDD when combined with antidepressant therapy. Multimodal exercise offers immediate improvements, while mindfulness provides gradual, long-term benefits. These findings underscore the value of adjunctive lifestyle interventions in MDD management and highlight the need for further research into their long-term efficacy and potential synergistic effects. Clinical trial registration: Brazilian Registry of Clinical Trials, RBR-4pgd3ct, date of registration: 10/19/2023.