People suffering from post-traumatic stress disorder (PTSD) could someday be treated with the help of an electric patch worn on their head when they are sleeping, researchers say.

However, much further research is needed to confirm whether this treatment is actually effective or not, experts added.

In the small new study, 12 people who had been suffering from PTSD and depression for an average of 30 years — and were already being treated with psychotherapy, medication or both — wore the patch each night while sleeping, over an eight-week period. The researchers found that the severity of the participants' PTSD decreased by an average of more than 30 percent, and the severity of their depression dropped by an average of more than 50 percent, over the study period.

"Most patients with PTSD do get some benefit from existing treatments, but the great majority still have symptoms and suffer for years from those symptoms," Dr. Andrew Leuchter, senior author of the study and a psychiatrist at the University of California, Los Angeles, said in a statement. "This could be a breakthrough for patients who have not been helped adequately by existing treatments."

PTSD is a mental illness marked by severe anxiety, flashbacks and uncontrollable thoughts about a traumatic event. About 3.5 percent of the U.S. population has PTSD, the researchers said, including soldiers who have been in combat, and people who have survived terrifying events.

People with PTSD may try to avoid situations that could trigger flashbacks, which sometimes makes them reluctant to socialize or venture from their homes, leaving them isolated, the researchers said. People with the disorder are six times more likely than people who don't have PTSD to die by suicide, and they are at increased risk for marital difficulties and dropping out of school.

For the participants in the new study — who were survivors of rape, car accidents, domestic abuse and other traumatic events —the new patch delivered a kind of treatment known as trigeminal nerve stimulation (TNS). Prior research found that TNS can treat people with epilepsy who aren't helped by medication as well as people with depression who aren't helped by therapy, the researchers said. [Bionic Humans: Top 10 Technologies]

While a patient sleeps, a 9-volt battery powers the patch, which sends a low-level electrical current to nerves that run through the forehead. These nerves send electrical signals to parts of the brain, such as the amygdala and the medial prefrontal cortex, which regulate mood, behavior and cognition, and that previous studies found were linked with PTSD.

The study participants had chronic PTSD and severe depression. An average of 30 years had passed since the traumatic events that had left them depressed, anxious, irritable, hypervigilant, unable to sleep well and prone to nightmares.

While they continued their regular treatments, they also wore the patch when they slept, for 8 hours a night. The participants completed questionnaires about the severity of their symptoms and the degree to which the disorders affected their work, parenting and socializing at the start and end of the study.

"We're excited that we're seeing strong evidence that TNS may be helpful to patients with PTSD," Leuchter said. "This was a group of patients that had been ill for years, and had been through all the best available treatments without significant relief for most of their symptoms. The fact that we could relieve symptoms in this chronically and seriously ill group was surprising and very encouraging."PTSD symptoms stopped completely for one-quarter of the patients in the study. In addition, participants generally said they felt better able to take part in daily activities.

The treatment worked best in patients who used the device consistently for eight weeks — participants who were inconsistent in using the device did not have as good outcomes, Leuchter said. Future research will examine the long-term effects of this treatment, he added.

"I recall one woman who came in who was just delighted," Leuchter told Live Science. "After using the device for just a few weeks, she said she was able to sleep through the night for the first time in years without nightmares."

This is the first evidence that TNS can help treat people with chronic PTSD, the researchers said. The treatment showed no serious side effects during the course of the study. "Some subjects showed some slight skin irritation on the forehead where the patch was applied, and this was easily addressed by moving the patch or applying some skin cream," Leuchter said.

"Some of the study subjects have continued to use the device for months or years as part of the study and have continued to show benefit," Leuchter said. "Some other subjects who stopped using the device also have maintained their improvement." [5 Amazing Technologies That Are Revolutionizing Biotech]

One of the participants died by suicide in the seventh week of the study. The person had denied having any suicidal thoughts at the start of the research and throughout it. The researchers noted the participant's treating psychiatrist, who was not affiliated with the study, concluded the suicide was more likely related to the person's underlying psychiatric illness than to the device or study.

Much further research is needed to see whether this strategy is actually effective at treating PTSD, said Dr. Paul Rosch, a clinical professor of medicine and psychiatry at New York Medical College who was not involved in the new study.

He noted this preliminary study was small, and no sham treatment was given to participants to examine whether any benefits of the study were due to the device itself or just the placebo effect, "which is not uncommon in electric and magnetic stimulation studies," Rosch told Live Science.

The researchers are now testing the patch in a larger study — they are recruiting 74 veterans who have served in the military since 9/11. PTSD affects a greater percentage of military veterans than civilians —an estimated 17 percent of active military personnel experience symptoms, and about 30 percent of veterans who have returned home from service in Iraq and Afghanistan have had signs of the disorder, the researchers said.

In this larger study, half of the veterans will get TNS, and half will receive a fake TNS patch. At the end of this study, volunteers who got the fake patch will receive the option of undergoing actual TNS.

"PTSD is one of the invisible wounds of war," study lead author Dr. Ian Cook, of the University of California, Los Angeles, said in a statement. "The scars are inside, but they can be just as debilitating as visible scars. So it's tremendous to be working on a contribution that could improve the lives of so many brave and courageous people who have made sacrifices for the good of our country."

Cook, who co-invented TNS, is now on leave from his position at UCLA and is serving as chief medical officer at NeuroSigma in Los Angeles, which is licensing the technology and funding the research. NeuroSigma is already marketing the patch overseas and has plans to make it available to patients in the United States.

The scientists detailed their findings online today (Jan. 28) in the journal Neuromodulation: Technology at the Neural Interface.

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