"Powerful magnetic pulses applied to the scalp to stimulate the brain can bring fast relief to many severely depressed patients for whom standard treatments have failed. Yet it's been a mystery exactly how transcranial magnetic stimulation, as the treatment is known, changes the brain to dissipate depression. Now, research led by Stanford Medicine scientists has found that the treatment works by reversing the direction of abnormal brain signals."
"When they analyzed fMRI data across the whole brain, one connection stood out. In the normal brain, the anterior insula, a region that integrates bodily sensations, sends signals to a region that governs emotions, the anterior cingulate cortex.
"You could think of it as the anterior cingulate cortex receiving this information about the body—like heart rate or temperature—and then deciding how to feel on the basis of all these signals," Mitra said.
In three-quarters of the participants with depression, however, the typical flow of activity was reversed: The anterior cingulate cortex sent signals to the anterior insula. The more severe the depression, the higher the proportion of signals that traveled the wrong way."
"When depressed patients were treated with SNT, the flow of neural activity shifted to the normal direction within a week, coinciding with a lifting of their depression."
https://medicalxpress.com/news/2023-05-depression-reversing-brain-wrong.html [medicalxpress.com]