MINNEAPOLIS, Minn. — Electrical stimulation is becoming a more common tool for scientists trying to boost brain performance. Now, a new study has discovered one particular spot that may hold the key to treating mental illness. Scientists say stimulating the brain’s internal capsule both improves mental function and helps patients dealing with conditions like depression focus their thoughts.
The findings come from a pilot study of 12 patients undergoing brain surgery for epilepsy. Doctors placed hundreds of small electrodes throughout a patient’s brain which record mental activity and spots the areas where seizures start.
A team from the University of Minnesota Medical School and Massachusetts General Hospital found that applying small amounts of electrical stimulation to the internal capsule improved each patients mental function. The scientists say this part of the brain handles cognitive control, a process which helps a person shift from one thought to the next. Mental illness often impairs this ability.
“An example might include a person with depression who just can’t get out of a ‘stuck’ negative thought. Because it is so central to mental illness, finding a way to improve it could be a powerful new way to treat those illnesses,” says Minnesota Medical School’s Alik Widge, MD, PhD, an assistant professor of psychiatry, in a university release.
Decoding when a person needs a brain boost
Study authors developed a computer algorithm that could track the cognitive control abilities of patients after they underwent brain stimulation. It could also track when these abilities began to drop off. The controller method they created sent boosts of stimulation whenever a patient started to do worse during lab tests measuring cognitive control.
“This system can read brain activity, ‘decode’ from that when a patient is having difficulty, and apply a small burst of electrical stimulation to the brain to boost them past that difficulty,” Widge explains. “The analogy I often use is an electric bike. When someone’s pedaling but having difficulty, the bike senses it and augments it. We’ve made the equivalent of that for human mental function.”
Researchers add that their results are the first to show that precisely targeted electrical stimulation can reverse the declines in mental function due to mental illness. The team also found that there are specific regions in the internal capsule which electrical stimulation is particularly effective in treating.
A new tool are improving mental health issues
Study authors note that some of the epilepsy patients also suffered from high levels of anxiety. After undergoing electrical stimulation, they reported experiencing lower levels of anxiety. The participants added that they were able to shift their thoughts away from topics distressing them to the thoughts they wanted to focus on. Widge believes stimulating the internal capsule could therefore become a new treatment for drug-resistant cases of anxiety, depression, and other mental conditions.
“This could be a totally new approach in treating mental illness. Instead of trying to suppress symptoms, we could give patients a tool that lets them take control of their own minds,” Widge says. “We could put them back in the driver’s seat and let them feel a new sense of agency.”
Since the U.S. Food and Drug Administration has already approved deep brain stimulation for use in improving brain health, researchers believe they’ll be able to use existing tools to make this new treatment available sooner rather than later.
“The wonderful thing about these findings is that we are now in a position to conduct clinical trials to further demonstrate effectiveness and then hopefully move to helping treatment-resistant patients who are in desperate need for additional interventions to treat their illnesses,” concludes Darin Dougherty, MD, an expert in clinical brain stimulation.
The study is published in the journal Nature Biomedical Engineering.