Effects of transcranial magnetic stimulation on sleep quality and mood in patients with major depressive disorder

Study Objectives: It is unknown whether sleep quality improvements after repetitive transcranial magnetic stimulation (rTMS) are inherent to the intervention or related to improvements in depressive symptoms. This retrospective study examined sleep quality in patients with major depressive disorder before and after treatment with rTMS, adjusting for age, sex, sedative-hypnotic use, number of rTMS treatments, depression severity, and changes in depressive symptoms. Methods: Adults with major depressive disorder underwent a 6-week course of 10 Hz rTMS over the left dorsolateral prefrontal cortex. Patients completed the Patient Health Questionnaire-9 depression rating scale and the Pittsburgh Sleep Quality Index before and after treatment. To limit confounding, analysis of depressive symptoms occurred without item 3 (the sleep item) of the Patient Health Questionnaire-9. Results: Twenty-one patients completed the study, with a mean (+/- standard deviation) baseline Pittsburgh Sleep Quality Index score of 12.0 (+/- 3.8), compared to 10.5 (+/- 4.3) posttreatment (P = .01). The mean baseline Patient Health Questionnaire-9 score without item 3 was 17.3 (+/- 3.0), compared to 12.2 (+/- 4.9) posttreatment (P = .0001). Pittsburgh Sleep Quality Index and modified Patient Health Questionnaire-9 changes were uncorrelated in nonadjusted and adjusted linear regression models and in the Spearman rank-order correlation. Conclusions: Mood and sleep quality improved independently after rTMS treatment, even after adjusting for age, sex, sedative-hypnotic use, number of rTMS treatments, and depression severity. These findings suggest that rTMS exerts direct effects on both mood and sleep in patients with major depressive disorder.