How Hormones Could Predict Who Gets PTSD

A new study on soldiers suggests that cortisol might be a key factor.

Mar 10 2017, 10:14pm

Chris Anderson/Getty Images

For soldiers returning from wartime deployments in Iraq and Afghanistan, post-traumatic stress disorder is a major problem. The US Department of Veteran's Affairs estimates that up to 20 percent of those veterans developed some symptoms of PTSD; the disorder can be crippling, leading in extreme cases to an inability to trust others and a constant feeling of being in danger. A new study suggests that by looking at hormone levels, doctors may be able to predict which soldiers have a predisposition to PTSD—and possibly work to prevent it. 

Researchers from The University of Texas at Austin homed in on cortisol, a hormone the body releases during emergencies. It's a key part of the fight-or-flight response, and previous research had associated abnormal cortisol levels with an increased risk for PTSD. But the effects and interactions of hormones in the body are famously complex, and follow-up research never pinned down cortisol as a primary driver of PTSD. 

The new research suggests cortisol does play a critical role, but only when testosterone (another hormone, and one of the most important for men) is suppressed. The two have a dynamic; the study's lead author said in a statement that, "It is becoming clear to many researchers that you can't understand the effects of one without simultaneously monitoring the activity of the other." Past research may have hit a roadblock with cortisol because it failed to account for the effects of testosterone. 

The UT researchers came to that conclusion by using hormone data from 120 US soldiers. Their stress responses were tested before deployment; the normal response was elevated cortisol. Some soldiers, though, showed no change in the hormone—an abnormal response. 

The soldiers' combat experiences were tracked, giving researchers a catalog of their war-time experiences and exposure to stress and trauma. Those who'd shown an abnormal cortisol response to the stress test were more likely to develop PTSD, but only if they didn't also have an elevated testosterone response to the same test. In other words, they were more likely to develop PTSD if they had both an abnormal cortisol response and no elevated testosterone response. 

That's a more complicated situation than "this hormone causes PTSD." But it's also to be expected: Hormones interact with one another in remarkably complex ways. The research, does, however, suggest to scientists that they're at least looking in the right general area. It's also part of a larger project at the US Department of Defense aimed at identifying the predictive factors for PTSD. In time, that could lead to interventions that won't simply treat post-traumatic stress disorder, but prevent it from happening in the first place. 

Read This Next: Can Researchers Treat PTSD Without Using Triggers?