PTSD Raises Suicide Risk, But How?
Date: February 1, 2010
Posttraumatic stress disorder and young adulthood can be a lethal mix. For people in their late teens and early 20s, having PTSD puts them at increased risk of attempting suicide, a recent Hopkins study has shown.
“The tie to PTSD wasn’t such a surprise,” says the study’s leader, Holly Wilcox, as other researchers have shown that exposure to sexual abuse or some other trauma—triggers for PTSD—raises the likelihood of a suicide try in adults.
But Wilcox’s eye picked out something most studies had overlooked: the idea that having PTSD itself was what was important. “In other words,” she says, “it’s likely that the particular response to trauma is more crucial as far as suicide is concerned.” And that’s what her new study showed.
By following up on nearly 2,000 children tracked since they entered Baltimore public schools some 15 years ago, Wilcox’s team gathered robust data implicating PTSD rather than trauma alone in raising the risk of suicide attempts. It’s a find with the immediate benefit of sensitizing psychiatrists to this risk in their young adult patients. And what should raise more red flags is the study’s conclusion that those most in danger have PTSD following “assaultive” violence like rape or stabbing.
As important to Wilcox, though, is that the work adds to her mission to show how environment and genetics interact early on to turn people on the cusp of life against their own bodies. “What I want most,” she says, “is to understand the biology behind self harm in young people—cutting as well as suicide.” And her approach as a psychiatric epidemiologist—one of a handful at Hopkins—lets the large numbers of patients she studies become a laser pointer showing where to look for answers.
Wilcox holds that stress and trauma “dysregulate emotional parts of the brain,” which, in turn, may make people more impulsive, more likely to hurt themselves. To prove that, though, some basic questions need answering. Exactly how might PTSD or depression—a more traditional suicide risk—alter emotional pathways? Do those disorders hold common genes that make such pathways vulnerable?
Wilcox’s newest studies make a start. Currently, she’s sampling the DNA of 100 older teens marked “at risk” by having a parent with a history of severe depression. A similar study is ongoing with her earlier PTSD subjects. She’s also measuring their levels of cortisol, a byproduct of the HPA axis, the body’s stress pathway.
“A dysregulated axis–with it’s high cortisol–appears to make people more impulsive,” Wilcox explains. And a body of work ties depression and high cortisol. “It’s more complicated with PTSD, though,” says Wilcox, “because there, cortisol response seems blunted. What it boils down to, I think, is that in either illness the HPA axis isn’t working normally.” The new work should help sort it out.
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