Post-traumatic stress disorder (PTSD) sufferers have reported large improvements in their symptoms after wearing an electronic patch that stimulates a cranial nerve. The initial study was small and did not have a control group. However, the benefits described were so significant that researchers are optimistic for the treatment's future.
PTSD is defined as an ongoing psychological disturbance in response to a violent or stressful experience. It is estimated to affect around 3.5 percent of American adults. In financial terms alone, the U.S. cost is around $45-50 billion a year, with treatment typically involving counseling such as cognitive behavioral therapy or antidepressant medication, like Prozac.
"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," said UCLA professor Andrew Leuchter in a statement. It is common for PTSD to co-occur with other mental health conditions, worsening the prospects of treating either.
For the study, Leuchter recruited 12 adults with long-term PTSD and major depressive disorder (MDD), and had them wear a patch powered by a 9-volt battery on their forehead at night. The patch sends signals through the cranial nerves to parts of the brain shown to be disturbed in PTSD sufferers. The process, known as trigeminal nerve stimulation (TNS), has some common ground with transcranial magnetic stimulation (TMS), but avoids the need for frequent hospital visits. It has already shown some success against epilepsy and depression that have not responded to other treatments.
In Neuromodulation: Technology at the Neural Interface, Leuchter and colleagues report on the patients' response to eight weeks of treatment, during which time the patients maintained their previous antidepressant drug programs. Tragically, one patient committed suicide during the trial, despite reporting improvements to his psychiatrist. The remaining patients showed dramatic improvements on multiple measures of depression and PTSD, largely within the first two weeks, and most reported no side effects.
"We're talking about patients for whom illness had almost become a way of life," said Leuchter. "Yet they were coming in and saying, 'For the first time in years I slept through the night,' or 'My nightmares are gone.' The effect was extraordinarily powerful."
The trial was a “proof of concept” and therefore insufficient to prove the efficiency of TNS because it lacked a control group given a non-working version of the patch. Without this, it is not possible to be sure whether some or all of the benefits were the result of the placebo effect. In addition, there appears to have been no follow-up investigations, so it's unclear how long-lasting the treatment is.
Leuchter plans to address this deficiency with a larger study. He is recruiting 74 military veterans with PTSD from the Greater Los Angeles area. Half of these participants will be given the real TNS patch and half a fake version.
The authors have high hopes for TNS treating PTSD because the trigeminal nerve (stimulated in the process) connects to the part of the brainstem that sends signals to areas of the brain thought to be important in PTSD. “As a result,” they write, “the trigeminal system is neuroanatomically well placed to exert influence on cortical and subcortical structures involved in cognitive, affective, and behavioral symptoms of PTSD.”