Combat Tied to New-Onset PTSD, Comorbidities

ATLANTA — Combat deployments are difficult and stressful, and might be the primary driver of postdeployment mental health symptoms, including new-onset posttraumatic stress disorder, suggests an ongoing study of more than 55,000 military personnel.

In addition, smoking and problem drinking are associated with more mental health symptoms among active service members and Guard or Reserve personnel in the longitudinal Millennium Cohort Study.

“PTSD, of course, comes with many comorbidities. [Problem drinking] is one of them,” Tyler C. Smith, Ph.D., said at the annual meeting of the International Society for Trauma Stress Studies.

Dr. Smith and his associates assessed possible coping behaviors. “A significant amount of newly reported smoking and problem drinking is associated with new-onset PTSD.” Of those with baseline symptoms of posttraumatic stress disorder (PTSD), for example, 12% reported an alcohol-related problem, and 20% started smoking within 5 years of follow-up.

Dr. Smith and his colleagues assessed data from the PTSD Checklist–Clinical Version and the PRIME-MD patient health questionnaire. The survey also includes questions such as: “Has your doctor ever told you that you have PTSD or depression?”

At baseline, the weighted prevalence of PTSD was 3.6%. At 5 years, about 7% of those who had a PTSD screen were diagnosed with the disorder. In addition, about 49% of the cohort had a mental health diagnosis at 5 years.

New-onset PTSD symptoms were reported by 8.7% of those deployed with combat, 2.1% of those deployed without combat, and 3.0% of those who did not deploy.

“Not all deployments are equal, but there are subpopulations at risk for higher symptoms,” said Dr. Smith, principal investigator of the Millennium Cohort Study and a researcher at Naval Health Research Center in San Diego. He had no relevant disclosures.

Military personnel with a history of assault might be a more vulnerable population, for example. New-onset PTSD symptoms or diagnosis among those deployed to combat was identified in 22% of women who reported prior assault and 10% of women who did not. Similarly, new symptoms or diagnosis was identified in 12% of men who deployed to combat and reported prior assault and 6% of men who did not.

Combat deployment also increased the likelihood of smoking. Dr. Smith and his colleagues found smoking reuptake played a larger role than smoking initiation. In addition, there was a dose-response relationship: More or longer deployment(s) were associated with increased smoking rates.

Weight gain and physical activity also were studied. “Those with new-onset PTSD symptoms experienced 3 to 4 pounds of weight gain, compared to those without new symptoms,” Dr. Smith said.

The good news is that participants reporting light-to-moderate exercise were less likely to report new onset symptoms at follow-up. In addition, vigorous physical activity was associated with decreased odds of new-onset, persistent PTSD symptoms.

Dr. Smith and his associates also looked at new-onset depression. They found almost 6% of men and 16% of women exposed to combat reported this outcome.

The cohort is a random sample, but might not be representative of all military personnel or all those who deploy, Dr. Smith said at the meeting, which was cosponsored by Boston University. Use of a self-reported exposure assessment is another potential limitation, as is use of a mental health screen, which might not be a good surrogate for diagnosis by a health care professional, he added.

A minority of military personnel in the study represent the majority of those with posttraumatic distress symptoms, Dr. Smith said. “About 22% participants are contributing to about 60% of the postcombat PTSD symptoms. This is an area we could focus on [in future studies].”

The Department of Defense sponsors the Millennium Cohort Study. The primary aim is to follow military personnel over time to assess their health risks during active duty and thereafter.

An initial 77,000 military personnel were enrolled in 2001. A second panel of about 31,000 personnel was added in 2004, followed by a third panel of 43,000 others in 2007.

Visit www.millenniumcohort.org for more information.