Researchers at the Minneapolis VA Medical Center are testing low-level electrical brain stimulation to reduce impulsivity and recklessness in veterans — a problem for some soldiers who struggle with tame civilian life after the chaos and trauma of wartime deployments.
Impulsive, dangerous behavior is a hallmark of alcoholism, depression and post-traumatic stress disorder, so figuring out ways to reduce it could help veterans and others who are prone to those disorders, said Casey Gilmore, a leader of the research.
"Maybe treating the underlying impulsive behaviors will at least mitigate the effects of the disorders," he said.
The researchers attached electrodes on the scalps of six veterans with impulse-control problems — near the prefrontal cortex portions of their brains, which are associated with decision-making. The six were then asked to pump up a balloon — getting points as the balloon got larger, but losing points if the balloon popped.
All six felt the initial tingle as the current increased to 2 milliamperes, but only three had the current active for the full 20 minutes of the exercise.
"Risky people tend to keep on pumping to try and get more points until it explodes," said Gilmore, who is leading the research under a contract with the U.S. Department of Defense and its Defense and Veterans Brain Injury Center.
Gilmore's team theorized that this "transcranial direct current stimulation" (tDCS) would be more effective if patients were simultaneously using the portions of their brains that were targeted — hence the balloon exercise.
After two months of treatments, researchers tested the participants' impulsivity with another exercise. In this case, the veterans earned points by finding a token under blocks, but were tantalized with more points if they chose blocks that were least likely to conceal it. "That's sort of a hallmark of impulsivity," Gilmore said. "They make these rash decisions and don't consider the long-term consequences."
Impulsive decision-making dropped 16 percent in veterans who received the current but only 6 percent in those who received the sham treatment.
Gilmore differentiates tDCS from electroconvulsive therapy, or ECT, which uses higher electrical currents to cause seizures that alter brain chemistry in ways that reduce symptoms of certain mental illnesses. Veterans couldn't feel the current during tDCS, which is why they didn't know if they were receiving the real treatment. Gilmore tried it himself and said he couldn't feel it.
He added that tDCS must be studied in larger populations, and in context with medications and other treatments people receive, before being used in clinical care.
"This was sort of a pilot study to see if this was worth following up," he said. "Now we're in the process of expanding this project."
Jeremy Olson • 612-673-7744
