Science and Technology

Researchers report first objective test of post-traumatic stress

Discovery could lead to safer diagnostic status of patients with debilitating disorder

Foto: Nestor Müller / Secom
Professional performs tomography on patient
Professional performs tomography on patient

Tapping into the "babble" between groups of neurons in the brain, University of Minnesota researchers have linked a pattern of signals to post-traumatic stress disorder (PTSD), a debilitating condition for which there is no objective test.

Such a test could give doctors a way to diagnose PTSD, assess its severity, and evaluate treatments. It could also guide those who decide who is entitled to disability payments or which soldiers are fit for redeployment.

PTSD patients typically suffer from nightmares and relive involuntarily traumatic experiences. The disorder can be caused by almost any situation of intense fear or violence, such as sexual assault, a car accident, or the horrors of battle.

"Across all types of disabling diseases, PTSD consistently ranks in the top 20, especially among women," says Engdahl. "The current lifetime prevalence is about 3.4 percent for men and 9.7 percent for women. The cost in human and economic terms is staggering."

As with nearly all mental disorders, PTSD leaves few clues for the outside world to latch onto. Neither X-rays nor brain scans like CT or MRI can identify patients who have it.

"It's like depression in that it can be hidden by the sufferer, it can be latent, and it can be re-activated," says Georgopoulos. "That's a major issue for the Army, which has to decide whether to re-deploy troops who have had it."

Many people who suffer from a stress disorder keep silent in order to protect their careers, says Engdahl, who has counseled PTSD patients. "But in talking to them, somehow the notion that high-technology could detect some abnormalities is comforting. An objective test for PTSD may help remove some of the stigma."

The researchers examined 74 veterans of conflicts in World War II, Vietnam, Iraq, or Afghanistan who had been diagnosed with PTSD, along with 250 healthy volunteers. Using a technique developed by Georgopoulos, they monitored magnetic signals from groups of neurons in communication with each other.

They noted a pattern of miscommunication that was nearly unique to PTSD patients. Overall, they were able to identify people as PTSD patients or healthy controls with more than 90 percent accuracy.

"Compared to evidence from functional MRI and other diagnostic tools currently being accepted by courts for other disorders, this test is much stronger and has a higher probability of being accepted as evidence by courts," Georgopoulos says.

The pattern seen in PTSD patients appears to be a flaring up of brain networks that have to do with reliving experiences. Also, the strength of the pattern mirrored the severity of symptoms, suggesting that the test may be used to monitor a patient's progress during treatment.