Sleep as a predictor of improved response to transcranial magnetic stimulation for depression (SPIRiTeD)

Transcranial magnetic stimulation (TMS) is an evidence-based approach to treatment- resistant Major Depressive Disorder (TRD). Sleep dysfunction is associated with poor outcomes in TRD, however, the impacts of sleep dysfunction on TMS treatment has yet to be defined. This study examined the association between sleep dysfunction and improvement in depression symptoms with TMS treatment for TRD.

A retrospective observational cohort study was conducted examining all Veterans receiving TMS treatments through the "VA TMS Clinical Pilot Program" over a three-year period. The Patient Health Questionnaire (PHQ-9) sleep item was utilized to assess sleep dysfunction. The association between sleep dysfunction improvements during TMS treatment with depression outcomes was analyzed.

94.3 % (N = 778) of Veterans reported baseline sleep dysfunction. Chi-square analysis demonstrated higher rates of depression remission at the completion of TMS treatment for those with sleep improvement at weeks 1, 3 and 6 (all p < .001). ANOVA comparing sleep improvements and end of treatment PHQ-8 score (modified to remove sleep item) found a statistically significant difference in mean improvements of depression scores at all 3 time points.

Limitations include those that are inherent to retrospective studies, as well as limitations in using the PHQ-9 sleep item as the primary means to assess sleep dysfunction.

This study reports on the largest sample size to date examining the relationship between sleep dysfunction and TMS treatment outcomes for MDD, and found that improvement in sleep dysfunction was associated with greater reductions in end of treatment depression symptoms including higher depression remission rates.