Objectives: Deep transcranial magnetic stimulation (DTMS) has been shown to be efficacious and relatively safe for major depressive disorder (MDD). However, its clinical utility as an augmenting strategy for treatment-resistant depression (TRD) remains unexplored.
Methods: In an open label trial, 17 outpatients with severe TRD received 4 weeks of daily high frequency DTMS over the left dorsolateral prefrontal cortex. Depressive and anxious symptoms, suicidality and quality of life (QOL) were measured at baseline (i.e., in the week prior to the start of the DTMS treatment) and at week 5 (i.e., in the week following the end of the DTMS treatment). Primary outcome measures were rates of response and remission at week 5 using an intention-to-treat approach.
Results: Response and remission rates at week 5 were 70.6 and 41.2%, respectively. Also, depression, anxiety, and suicidality ratings were significantly improved by week 5 (with Hedges' g estimates ranging from 0.6 to 1.72), as well as four of the five QOL domain scores (i.e., global, psychological, environmental and social). Finally, two patients dropped out of the study at week 1 because of significant scalp discomfort during stimulation.
Conclusions: Our study suggests that DTMS, when used as an augmenting strategy for antidepressants in severe TRD, is efficacious, safe and relatively well tolerated. However, controlled studies with larger samples are needed to confirm and expand our preliminary findings.
Keywords: prospective study; quality of life; transcranial magnetic stimulation; treatment-resistant depression; unipolar major depression.