Effectiveness of Prefrontal Transcranial Magnetic Stimulation for Depression in Older US Military Veterans.

Objective: While typical aging is associated with decreased cortical volume, major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) likely exacerbates this process. Cerebral atrophy leads to increased coil-to-cortex distance and when using transcranial magnetic stimulation (TMS), potentially reducing effectiveness in older adults.

Methods: Data from a large-scale quality improvement project was used. Included veterans eligible for TMS and completed TMS treatment. Age was assessed as a predictive factor of depression outcomes after TMS treatment among veterans. Secondary analyses examined the impact of age on 1) MDD response and remission and 2) MDD change within MDD-only verses comorbid MDD and PTSD groups.

Results: The entire sample included 471 veterans. Primary analysis revealed age as a negative predictor of depression outcomes (p = 0.019). Secondary analyses found age to be a significant predictor of remission (p = 0.004), but not clinical response. Age was not a predictive factor in depression outcomes between those with MDD-only compared to MDD+PTSD.

Conclusions: Increased age predicts greater MDD symptom reduction after TMS. Although age did not predict response rates, it did predict increased rates of remission in veterans. Age did not differentially predict depression outcomes between those with or without PTSD. The sample size was sufficient to discern a difference in efficaciousness, and limitations were those inherent to registry studies in veterans. This data indicates that TMS can be an important treatment option for older individuals.