TUESDAY, Oct. 30, 2007 (HealthDay News) -- A study of U.S. veterans suffering from depression finds that their risk factors for suicide differ in surprising ways from those of other depressed Americans.
Specifically, the risk for suicide appears highest among younger veterans -- the reverse of what's seen in the general population.
And even though post-traumatic stress disorder (PTSD) can be deeply mentally distressing, veterans suffering with the disorder were actually less prone to suicide than those not afflicted by the condition.
The reasons for that remain unclear, the study authors said.
"It's possible that people with PTSD may be receiving additional services, they may have a greater connection to the VA health system -- more psychotherapy visits, for example," said lead researcher Kara Zivin, a Veterans Administration investigator and assistant professor of psychiatry at the University of Michigan at Ann Arbor.
Her team published its findings Tuesday in the online edition of the American Journal of Public Health.
Military service comes with special challenges, and the 1999 Veterans Health Study found that nearly a third -- 31 percent -- of veterans were suffering depressive symptoms, a rate that's two to five times higher than observed in the general public.
Now, as a new generation of soldiers returns from Iraq and Afghanistan, Zivin's team sought to better understand the risks depressed veterans face for suicide. To do so, they pored through data from the VA's National Registry for Depression for the years 1999 to 2004.
Overall, the researchers looked at information on almost 808,000 veterans diagnosed with depressive symptoms; 1,683 (0.21 percent) of those veterans took their own lives.
The researchers compared the characteristics of the depressed veterans who committed suicide against the characteristics of those who did not.
Dividing veterans into three groups by age -- 18 to 44 years, 45 to 64 years, and 65 or over -- Zivin's team found that the youngest group was at higher risk of suicide. Veterans aged 18 to 44 committed suicide at a rate of about 95 suicides per every 100,00 person years, versus about 78 per 100,000 person years in the group aged 45 to 64, and 90 per 100,000 for those 65 or older.
That findings are at odds with suicide trends among the general population, where younger depressed people are typically at lower risk than older individuals, the researchers said.
Zivin said the finding for veterans "wasn't what we expected, and our data doesn't allow us to figure out why that happened." She also said the finding should serve as a heads-up to doctors that a veteran's youth does not make him or her any less of a risk for suicide -- and might even add to the risk.
Dr. Marcia Valenstein, senior author of the study and an assistant professor in the department of psychiatry at the University of Michigan, added, "Clinicians have to be aware that they can't simply rely on the predictors of suicide in the general population -- in this depression treatment population, it is the younger individuals who are most at risk rather than the older individuals."
Another surprise finding was that a diagnosis of PTSD actually helped protect veterans against suicide. Depressed veterans with PTSD had a suicide rate of about 68 per 100,000 person years, the study found, while the rate was much higher in veterans without the disorder -- almost 91 suicides per 100,000 person years.
That finding was also a bit of a puzzle, Zivin said. She speculated that PTSD may encourage affected depressed veterans to more readily seek out psychiatric care.
Another expert agreed.
"The VA system is now much more accepting of looking out for, and hearing about, PTSD -- it's on the tip of everyone's tongue," said Dr. Charles Goodstein, a psychiatrist at the New York University Medical Center and professor of medicine at the NYU School of Medicine.
Compared to depression, PTSD "has become a more acceptable set of symptoms with which a person can present himself," said Goodstein, who is also a co-founder of a nonprofit, free mental health outreach program aimed at veterans called The Soldiers Project (www.thesoldiersproject.org).
"So, both the doctor's antenna is up [for PTSD], and the vet is more likely to be able to bring it to the doctor's attention, because there won't be such a stigma connected to it as there might be with depression," he said. As the PTSD patient receives needed care, his or her risk for suicide should decline, Goodstein said.
Similarly, the study found that depressed veterans with any physical disability were also at lowered risk for suicide -- possibly because they, too, saw doctors more often.
Other risk factors for suicide mirrored those seen in the general population. Veterans struggling with depression were much more likely to kill themselves if they were also battling substance abuse, the study found. Depressed male veterans were about three times as likely to kill themselves compared to females, and whites were at higher risk than blacks or Hispanics.
Due to a lack of data, the study was not able to assess the impact of specific military activity, such as active combat, on risks for depression and suicide.
The real challenge, experts agreed, is to make sure that all veterans struggling with depression get the care they need.
Certain VA centers "are beginning to set up what's called a Suicide Attempts Registry so that they can follow veterans who are at higher risk," said Gregory K. Brown, a specialist in these issues.
"I think having registries that follow up on high-risk veterans is one of the ways to go," said Brown, a research associate professor in the department of psychiatry at the University of Pennsylvania.
The VA has also set up a special suicide hotline specifically aimed at veterans, accessed toll-free at 1-800-273-TALK.
Still, some improvements could be made, Brown added.
"While the VA have both mental health programs set up and substance abuse programs, they need to have ways of merging the two programs so that veterans who have both disorders get [coordinated] treatment," he said.
A veteran's family and friends can help, too.
"Families should take any comments about suicide or 'life is not worth living' seriously," Brown said. "They shouldn't pass it off as just somebody being upset."
"The key thing is to talk to people," she said. "It's hard to know without conversation what someone is thinking."
For more about suicide and depression, visit the American Association of Suicidology.