Low-frequency right repetitive transcranial magnetic stimulation for the treatment of depression after traumatic brain injury: A randomized sham-controlled pilot study

Objective: Major depression is the most common psychiatric sequela of traumatic brain injury (TBI), but effective treatment continues to be a challenge, with few studies providing guidance. Methods: In a pilot study, the authors evaluated the effect size of low-frequency right-sided (LFR) repetitive transcranial magnetic stimulation (rTMS), compared with sham treatment, over the right dorsolateral prefrontal cortex (DLPFC) in patients (N=30) with TBI depression and co-occurring neuropsychiatric symptoms, including suicidal thoughts, anxiety, posttraumatic stress disorder, sleep disturbance, behavioral problems, and cognitive dysfuncti on. Expl oratory anal yses of di ffusi on tensor imaging pre-and postintervention were performed to determine the effect size of LFR rTMS on white matter integrity. Results: Small (Hedge’s g=0.19) and highly variable effects of LRF rTMS over right DLPFC in TBI depression were observed. Similarly, the effect of LFR rTMS for treatment of comorbid neuropsychiatric symptoms varied from small to moderate. Conclusions: These findings suggest that the observed effects of LFR rTMS over the right DLPFC in TBI depression and co-occurring neuropsychiatric symptoms are small, at best, and, preliminarily, that low-frequency right DLPFC stimulation has limited potential in this patient population. However, studies employing different rTMS parameters (e.g., type, location, frequency, duration) or other participant characteristics (e.g., TBI severity, chronicity, comorbidity, concurrent treatment) may potentially yield different responses.