THURSDAY, May 19 (HealthDay News) -- Children whose parents are deployed in Afghanistan or Iraq face a higher risk of psychiatric problems requiring hospitalization, a new study indicates.

Researchers from the Uniformed Services University of the Health Sciences tracked over 375,000 children, aged 9 to 17, whose parents were on active duty between 2007 and 2009.

"There was a 10 percent increased risk of hospitalization among children 9 to 17 whose parents were deployed," said Dr. Jeffrey Millegan, disaster and preventive psychiatry fellow at the Uniformed Services University of the Health Sciences.

He presented the finding this week at the American Psychiatric Association's annual meeting in Honolulu.

In all, the investigators found that 2,533 children in the study were hospitalized for a mental or behavioral health problem, staying a median of eight days.

Of that, about one-third, or 858 children, had parents who were deployed during the study period.

After taking into account factors such as past history of psychiatric problems, Millegan arrived at the 10 percent increased risk. When he looked at the parents' length of deployment, he found the link only held up when the parent was gone longer than six months.

More attention needs to be paid to the mental health of children of active duty military parents when they are deployed, the researchers said.

What can parents do to lessen the impact? While resilience research is still in its infancy, Millegan suggested that family doctors should ask parents about to be deployed how their children are doing.

Parents and others who are aware of the risk, he said, may better catch mental health problems when they are less serious than those needing hospitalization.

The study was deemed novel by Dr. Jeffrey Borenstein, chair of the American Psychiatric Association's Council on Communications, who moderated the Monday news conference announcing the findings.

"There really hasn't been this kind of research up until now on the effect on the children," he said. Previous research has linked a parent's deployment to war with increased anxiety and behavioral problems in their children.

Borenstein said the finding about length of deployment having an effect on the child's mental health was of particular interest. With further research, he said, the number of times a parent is deployed would likely be found to have an effect, too.

For now, he said, the research can help inform those involved and alert them to try to minimize the risk.

Millegan also found that children with a past history of mental health problems were more likely to have them again. The civilian parent's past psychiatric history also affected the child's risk of hospitalization for mental health problems.

The increased mental health problems, Millegan said, are likely related to the obvious family disruption that occurs when a major caregiver leaves for a period of time.

Other research has found that mental health issues can affect both the deployed parent and the parent who stays home, suggesting there could be a trickle-down effect. "It's quite clear that [the mental health issues faced by the parents] can have an influence on the children," he said.

Because this study was presented at a medical meeting, the data should be viewed as preliminary until published in a peer-reviewed journal.

More information

To learn more about how to help children with deployed parents, visit Our Military Kids.