A group of Emory University scientists wants to use a sweat test to pre-screen people for PTSD immediately following a traumatic event.
They measured hand sweat - an important measure of unconscious physical responses to threat - to see if perspiration would predict PTSD in people visiting the ER immediately following a potentially traumatic event.
More palm sweat did predict greater risks of PTSD down the road for many patients.
But the test also returned false positives, raising potential ethical questions.
Stress activates the sympathetic nervous system, including sweating. Emory University researchers think an over-active sweat response may predict who develops PTSD after trauma
Trauma is almost ubiquitous to the human experience - but post-traumatic stress disorder (PTSD) is not.
Estimates (and definitions) of how many people experience trauma in their lives and how many develop PTSD thereafter vary widely.
Some figures estimate that 51 percent of men and 61 percent of women go through a traumatic event, while others place that number as high as 70 percent overall.
About 20 percent of that 70 percent are thought to develop PTSD, but other estimates suggest that 10 percent of people the world over will develop long-term issues after trauma has passed.
The trouble is working out which 10 or 20 percent will develop PTSD and why.
'That's the million dollar question,' says Dr Tanja Jovanovic, an Emory University psychiatrist who is leading the development of the sweat test for PTSD.
It's also the subject of much of her research: 'Determining the biology that puts someone at risk, including possible genetic markers - genes that code for stress response - is an important component,' she says.
We also know that elements of personal history, such as childhood adversity or abuse and depression, increase the risks of developing PTSD at some point.
But these rather broad risk factors are not yet fine enough instruments to predict PTSD.
So Dr Jovanovic is developing a deceptively simple test: sweat.
Our bodies are equipped with an alarm and response to any kind of danger or threat, called the sympathetic nervous system.
Without us consciously telling it to, the body starts gearing up for fight or flight.
That means that adrenaline surges, heightening our senses and priming our musculoskeletal system to react quickly to
