The findings suggest that military service, and particularly combat experience, is a hidden variable in research on aging, said Carolyn Aldwin, director of the Center for Healthy Aging Research in the College of Public Health and Human Sciences at OSU and one of the study's authors.

"There are a lot factors of aging that can impact mental health in late life, but there is something about having been a combat veteran that is especially important," Aldwin said.

The findings were published this month in the journalPsychology and Aging. The first author is Hyunyup Lee, who conducted the research as a doctoral student at OSU; co-authors are Soyoung Choun of OSU and Avron Spiro III of Boston University and the VA Boston Healthcare System. The research was funded by the National Institutes on Aging and the Department of Veterans Affairs.

现有研究,研究the effects of combat exposure on aging and in particular on the impacts of combat on mental health in late life, Aldwin said. Many aging studies ask about participants' status as veterans, but don't unpack that further to look at differences between those who were exposed to combat and those who weren't.

Using data from the Veterans Affairs Normative Aging Study, a longitudinal study that began in the 1960s to investigate aging in initially healthy men, the researchers explored the relationship between combat exposure and depressive and anxiety symptoms, as well as self-rated health and stressful life events.

They found that increased rates of mental health symptoms in late life were found only among combat veterans. The increases were not seen in veterans who had not been exposed to combat.

Generally, mental health symptoms such as depression and anxiety tend to decrease or remain stable during adulthood but can increase in later life. The researchers found that combat exposure has a unique impact on that trajectory, independent of other health issues or stressful life events.

"In late life, it's pretty normal to do a life review," Aldwin said. "For combat veterans, that review of life experiences and losses may have more of an impact on their mental health. They may need help to see meaning in their service and not just dwell on the horrors of war."

Veterans' homecoming experience may also color how they view their service later in life, Aldwin said. Welcoming veterans home and focusing on reintegration could help to reduce the mental toll of their service over time.

Most of the veterans in the study served in World War II or Korea. Additional research is need to understand more about how veterans' experiences may vary from war to war, Aldwin said.

Aldwin and colleagues are currently working on a pilot study, VALOR, or Veterans Aging: Longitudinal studies in Oregon, to better understand impacts of combat exposure. The pilot study is supported by a grant from the OSU Research Office and includes veterans with service in Vietnam, the Persian Gulf and the post-9/11 conflicts.

The researchers have collected data from 300 veterans and are beginning to analyze it. Based on their initial findings, they are also planning a second, larger study with more veterans. They expect to see differences between veterans from different wars.

"Each war is different. They are going to affect veterans differently," Aldwin said. "Following 9-11, traumatic brain injuries have risen among veterans, while mortality rates have lowered. We have many more survivors with far more injuries. These veterans have had a much higher levels of exposure to combat, as well."

VALOR also offers researchers the opportunity to explore the impact of service on women veterans, whose experiences have not often been captured in previous research. About one-third of the participants in the pilot study were female veterans, Aldwin said.