As many as 1 in 5 veterans return from war with post-traumatic stress disorder. Their current options for treatment are some combination of behavioral therapy and medicine.
But those don't address the electrical circuitry at work in the brain, which scientists hope will provide a more precise option for treatment.
"We've focused a lot on the chemical side, because in the mid-20th century, we began to develop the first medications that affected neurotransmitters," said Dr. Darin Dougherty, director of the division of neurotherapeutics and the department of psychiatry at Massachusetts General Hospital. "The other side, the electrical, that's been less exploited as a treatment potential."
Dougherty and others are working to change that. With funding from the Defense Advanced Research Projects Agency, or DARPA, scientists are working to build new ways to treat psychiatric disorders, like PTSD, through deeper understandings of the electrical signals in our brains.
"What it really boils down to is precision interaction with neurons of the brain that are involved in neuropsychiatric illness," said Justin Sanchez, director of DARPA's biological technologies office.
Patients are already using early models; deep-brain stimulation is FDA-approved for the treatment of Parkinson's disease symptoms as well as obsessive compulsive disorder.
Liss Murphy has firsthand experience. She had a deep-brain stimulation device implanted 10 years ago to treat her severe depression. She now calls it a lifesaver after an episode of depression that started in 2004.
"Nothing could budge it," Murphy said. "I had a resume of like seven pages of all the drugs I tried. I did 30 rounds of [electroconvulsive therapy]. That did nothing; it didn't make a dent. It just got worse and worse and worse."
Out of options, Murphy agreed to try deep-brain stimulation — which is not FDA-approved for depression. It's a serious procedure, requiring brain surgery to put in place.
"Brain surgery just sounds so dramatic and severe and intense," Murphy said. "My greatest hope that day was that I would die on the table. I just had no — it was going to be my last shot: I'll do this and if it doesn't work I can say I tried everything."
But, Murphy said, "It worked."
The device, made by Medtronic, sends a constant electrical charge to her brain. The newer prototypes being worked on now will be a closed-loop system: Sensing misfires among neurons, and sending corrective charges when needed.
It may be an uphill battle. Previous large studies of the current deep-brain stimulation devices failed to show a benefit in treatment-resistant depression. But researchers like MGH's Dougherty say they hope the next generation of devices could present a whole new set of options for psychiatric disorders.
Murphy says she plans to wear her device for the rest of her life.
"The quality of life is much better and very different," she said. "Just this calmness, of, 'OK, this is what life is like.' It's not feeling nothing all the time or a complete void. I was content."