SALT LAKE CITY — Retired Sgt. Josh Hansen said he didn't think much about traumatic head injuries until he got blown up eight times.
As an improvised explosive device hunter in Iraq, he was in eight explosions and received six concussions.
"Either you see the stuff or you get blown up by it," he said.
Hansen said the injuries changed him.
"I used to like to read a book and it got to the point where I couldn't really focus on the book to read it," he said.
According to research at the University of Utah, the traumatic brain injuries put him at a higher risk of suicide.
"After sustaining an injury we see increased rates of insomnia," said National Center for Veterans Studies Associate Director Craig Bryan. "We see increased rates of depression, anxiety, post-traumatic stress disorder. All of these are risk factors for suicide, as well."
As an Air Force psychologist, Bryan ran a traumatic brain injury (TBI) clinic in Balad, Iraq in 2009. He accumulated a mountain of data fresh off the battlefield.
"Nobody had such an extensive database of service members within one or two days of their injury," he said.
Bryan's analysis of the information he collected confirms the generally-accepted link between TBIs and the risk of suicide, but it also shows soldiers who've had more than one TBI have a significantly higher risk.
One in 25 soldiers who had one TBI reported suicidal thoughts. Among those with multiple injuries, the ratio was one in five.
"Service member who had sustained multiple traumatic brain injuries were more sensitive to the negative effects of depression, so, in effect, the multiple TBIs turned up the volume of depression and made the depression riskier," he said.
Bryan said the evidence from his study and others seems to suggest that suicide risk is more closely linked to milder head injuries.
"And it is interesting that the milder forms of head injuries are what has been more strongly associated with psychological distress, sleep problems, depression, etc.," he said. "We don't really know why it is the case."
Hansen said he has also seen a link between suicide and head injuries. In Iraq he lost six men in combat. Since returning home, four of his men have taken their own lives. All of the four had TBIs, Hansen said.
"There's got to be something there," he said. "I don't know what it is. These guys that received injuries, it catches up to them."
This research is one small piece of a big puzzle — why the suicide rate among the military, which was once lower than that of the general public, has been rising. A recent study concluded deployment to war zones and combat were not major contributing factors. Most military personnel who commit suicide have not been in combat.
Hansen said he wasn't suicidal, but did have a very hard time adjusting to life after TBIs. Prior to his military service, he was a mechanic for pro motocross racers. He said he couldn't do that job anymore.
"You know what your life used to be and what you could do and now you can't do any of that stuff and you go into this huge depression," he said.
He said he really began to heal when he found a group called Wasatch Adaptive Sports. The group taught him how to ski, and they took him mountain biking and paddle boarding.
"You kind of change your life, adapt and overcome," he said. "And I think that's where my healing process started getting better."
Now Hansen, as a volunteer military liaison for the group, tries to encourage other injured veterans to get out and get involved.
"I've actually had soldiers tell me straight up, ‘Dude, I probably wouldn't be here right now if you wouldn't have come up here and convinced me to get outdoors and start doing things,' " he said.
"And that's really my goal," he said. "In Iraq you protected your men and took care of them and here at home I want to do the same thing. I don't want to lose any more men to suicide."