RTMS for Depression Increases Volume of Specific Brain Regions
Repeated transcranial magnetic stimulation (rTMS) is a treatment for depression in which magnets placed near the skull stimulate electrical impulses in the brain. In a poster presented at the 2015 meeting of the Society of Biological Psychiatry, Martin Lan and colleagues presented results of the first study of structural changes in the brain following rTMS.
In the study, 27 patients in an episode of major depression underwent magnetic resonance brain scans before and after receiving rTMS treatment over their left prefrontal cortices. Lan and colleagues reported that several cortical regions related to cognitive appraisal, the subjective experience of emotion, and self-referential processing increased in volume following rTMS treatment: the anterior cingulate, the cingulate body, the precuneous, right insula, and gray matter in the medial frontal gyrus. The increases ranged from 5.3% to 15.7%, and no regions decreased in volume. More than 92% of the participants showed increased gray matter in all of these regions.
The brain changes were not correlated with antidepressant response to rTMS, but suggest a possible mechanism by which rTMS is effective in some people. Lan and colleagues concluded that rTMS likely had neuroplastic effects in areas of the brain that are important for emotion regulation.