Deep brain stimulation could dampen depression
Researchers have pinpointed an area of the brain that could be targeted via deep brain stimulation to tackle treatment-resistant depression.
Deep brain stimulation – in which electrodes are implanted into brain areas and generate electrical impulses – has been utilized for years to treat movement disorders such as Parkinson’s disease, tremor, and dystonia. Utilizing PET imaging, a team of researchers from the University of Texas (TX, USA) has tailored the method to treat depression.
Although deep brain stimulation has been previously studied as a possible treatment for depression, locating the exact area of the brain that needs to be stimulated in order to achieve this has been tricky. In the study, the researchers decided to pinpoint an area of the brain termed the superolateral branch of the medial forebrain bundle, which has been linked to motivation and reward.
“We targeted a bundle of fibers that leave this small area in the brainstem to travel to other areas throughout the brain,” explained first author, Christopher Conner. “The PET scans indicated that this small target area has very diffuse downstream effects. It’s not one single effect because there’s not one single area of the brain linked to depression. The whole brain needs to be changed and through this one small target, that’s what we were able to do.”
The team performed the deep brain stimulation procedure on ten patients, conducting PET scans prior to the procedure, and at 6 and 12 months after the procedure, to monitor any changes that had taken place in the brain.
Among the patients, eight out of ten showed a response, meaning that they experienced at least a 50% decrease in their symptoms. Correlating with this reduction in symptoms, the PET scans revealed that metabolic brain changes had occurred over the 12 months after the procedure had taken place.
“This is something that people have been trying to do for a long time, but we have not always been very successful with using deep brain stimulation for psychiatric illnesses,” commented Conner. “But this PET study shows that we’re altering how the brain is functioning long term and we are starting to change the way [the] brain starts to organize itself and starts to process information and data.”
Importantly, these results reveal that deep brain stimulation could be a potential therapy for cases of depression that have proved difficult to treat with traditional methods, such as antidepressants or psychological counseling.
“…for patients with severe chronic treatment-resistant depression, decreasing our symptoms by half is a lot. It’s the difference between being disabled to being able to do something…” concluded co-author João de Quevedo.
