November 3 (HealthDay News) -- Children of U.S. military personnel deployed to Iraq and Afghanistan are more likely to have behavioral problems than children whose parents aren't deployed, a new study shows.

Researchers studied 169 families with children aged 18 months to 5 years old enrolled in a day-care center at a Marine base.

Of those families, 55 (33 percent) had a deployed parent, with an average deployment length of 3.9 months. The researchers found that children aged three years and older with a deployed parent had significantly higher scores on measures of externalizing and overall behavior problems than children of the same age without a deployed parent.

"Such reported differences might be dismissed as distorted perceptions of the child by the distressed non-deployed parent; however, the association remained after controlling for parental stress and depressive symptoms," wrote Dr. Molinda M. Chartrand, of the Boston University School of Medicine and Boston Medical Center, and colleagues.

"Larger, longitudinal studies are needed to ascertain whether there are changes in children's behavior from the time before parental deployment, during parental deployment, and at the time of reunification," the researchers added.

"This information is necessary to provide clinicians serving military families with evidenced-based anticipatory guidance and clinical interventions. Finally, the needs of the children of deployed parents in the National Guard and Reserves also warrant urgent further education."

The study was published in the November issue of the Archives of Pediatrics & Adolescent Medicine.

"Findings from this study highlight the need for increased attention to mental health concerns of young children of deployed soldiers as well as the mental health concerns of the soldiers and non-deployed spouses," David J. Schonfeld and Robin Gurwitch, of the Cincinnati Children's Hospital Medical Center, wrote in an accompanying editorial. "[The study authors] raise questions of how to best determine deployment length and what preventive measures can be taken to reduce stress and distress to the non-deployed spouses and children left behind."

More than 2 million American children have had parents deployed to Iraq or Afghanistan, and about 40 percent of those children are younger than 5.

SOURCE: JAMA/Archives journals, news release, Nov. 3, 2008