TMS for Generalized Anxiety Disorder (GAD)

Researchers are continuously coming up with creative new therapies using transcranial magnetic stimulation (TMS) as a treatment modality. Now, they have performed a new study using TMS to improve the symptoms of generalized anxiety disorder (GAD). Generalized anxiety disorder is characterized by chronic worry, tension and anxiety. These symptoms can often occur for no apparent reason and can be quite distressing. For this new study researchers recruited patients who had a diagnosis of GAD. They first performed an fMRI on the subjects to determine which area of the brain to target. This is one of the relatively few fMRI-guided TMS studies I have seen. Basically they take a brain scan, and then target the abnormal area visualized on that scan with TMS.

The goal of this pilot study was to evaluate whether functional magnetic resonance imaging (fMRI)-guided rTMS is effective in reducing symptoms of GAD.

It looks like they got fairly promising preliminary results from this trial.

RESULTS: Overall, rTMS was associated with significant decreases in HAM-A scores (t = 6.044, p = .001) indicative of clinical improvement in GAD symptoms. At endpoint, 6 (60%) of the 10 participants who completed the study showed reductions of 50% or more on the HAM-A and a CGI-I score of 1 or 2; those 6 subjects also had an endpoint HAM-A score.

I think this shows that in the future, researchers will basically be able to look at a real time brain scan to tell which brain areas are overactive or underactive in those with mental illness. If a person is exhibiting a specific symptom associated with a particular brain region being overactive or underactive, they can then increase or decrease activity in that area using TMS or deep TMS. So TMS therapies can be individualized for each person. Researchers have already correlated specific symptoms of mental illness with metabolism in specific brain areas.

"Psychic depression correlated positively with metabolism in the cingulate gyrus (most of the dorsal posterior cingulate and subgenual anterior cingulate), thalamus, ventral striatum, hypothalamus and subgenual basal forebrain. Sleep disturbance correlated positively with metabolism in limbic structures and basal ganglia. Loss of motivated behavior shows a significant negative correlation with an extensive network of dorsal cortical regions, including the dorsolateral prefrontal cortex (PFC), dorsal parietal cortex, and dorsal temporal association cortices."

So in the future, I think there will be a move to diagnosing specific symptoms as opposed to labeling disorders. Usually most mental illnesses are quite heterogenous, as different people may suffer from different symptoms and different brain overactivity or underactivity.