Veterans' brains may help unlock PTSD mysteries
Patients with post-traumatic stress disorder may soon have access to personalized treatments thanks to a collaboration announced a week ago between Stanford Medicine and Cohen Veterans Bioscience.
The collaboration will examine 160 veterans who are currently receiving psychotherapy, the go-to treatment for PTSD, to try to identify a cognitive biomarker that can help scientists predict whether one of two types of psychotherapy will be more effective.
PTSD is a psychological disorder that arises after someone experiences or witnesses a traumatic event, such as a combat situation, natural disaster or sexual assault. About 3.5% of the U.S. adult population has PTSD at any given time, according to the National Institute of Mental Health.
"Not everyone who experiences a traumatic event is going to develop the condition," said Dr. Magali Haas, president of Cohen Veterans Bioscience, a nonprofit research organization focused on PTSD and Traumatic Brain Injury research affecting veterans.
In many cases, two people can experience the same event and one will develop PTSD while the other will not. Doctors have yet to determine why this is the case. The new study may bring them closer to unlocking this mystery.
"Although it is a psychological response to a traumatic event, it actually causes a change to the wiring of your brain," Haas said. "So the psychological experience turns into a biological response that we can measure, that we can intervene in when we finally understand those mechanisms."
The new research is based on an earlier study by Dr. Amit Etkin of Stanford Medicine. The details of that study are currently under embargo while the paper is being reviewed, but Cohen Veterans Bioscience thought them promising enough that they funded this follow-up study.
Etkin said the study may have identified a biomarker that could help diagnose PTSD. Currently doctors have no objective test for PTSD. Instead, they rely solely on interviews with patients to diagnose the disorder. Having a clear, measurable test could change the course of treatment, by helping doctors identify the disease and tailor treatments to individual patients.
Under the new study, patients who have been diagnosed with PTSD will be compared against a control of healthy patients with the goal of replicating Etkin's initial results.
"What we're looking for is a signature in their brain essentially, a descriptor of how different parts of their brain function together that tells us how efficient their brain is at processing information," Etkin said. "Imagine it's like an orchestra. An orchestra needs to work together, work in unison, to make the music sound good … Whose brain is making good sounding music and whose brain is falling apart?"
Like most psychological disorders, PTSD can manifest in many ways. Thus far, doctors have had no way of telling one type of PTSD from another. As a result, patients receive standardized treatments that may not help them.
"The idea, furthermore, is that if you don't have the right treatment for that subtype, you are giving either an ineffective or potentially harmful treatment to somebody who's not going to respond," Etkin said. "You realize just how strange our current approach is, which is this one-size-fits-all approach, which we know is not optimal, but we've not yet had the tools to go beyond it."
Etkin's early research investigated female civilians who had experienced sexual assault, car accidents, violent crimes or other traumatic situations. The new research will look at veterans.
"It happens that veterans are both an important population to study, but also an ideal context for trying to make the bridge to the real world and real world clinics because the VA has really done a wonderful job in rolling out standardized treatments," Etkin said.
If the new study successfully replicates and expands upon Etkin's earlier results, Cohen Veterans Bioscience would work to develop a definitive diagnostic test and get it approved for commercial use, Haas said.
"The reality is to understand it as you understand any chronic medical condition, like diabetes, like high blood pressure that leads to problems," Etkin said. "PTSD is exactly like that, it's a chronic condition that has no cure and it's biological in its basis, though psychological in its experience. You have to find the right intervention for the person and without that there's some very bad outcomes."