Researchers found boys had higher rates of mental health problems years after their families got vouchers to move out of impoverished neighborhoods, compared to boys who didn't get assistance.

On the other hand, moving out of high-poverty neighborhoods was linked to lower rates of depression and behavior problems among girls.

"The girls seemed like they were helped a lot by moving and the boys were hurt a lot," the study's lead author from Harvard Medical School in Boston Ronald Kessler told Reuters Health.

Between 1994 and 1998 the U.S. Department of Housing and Urban Development (HUD) implemented an experiment known as Moving to Opportunity, which recruited over 4,500 families with young children living in high-poverty areas.

The families were randomized to either receive vouchers to move their family to less impoverished communities or to not receive any new assistance.

An initial review of the children in the experiment four to seven years later found families that got vouchers moved to better neighborhoods.

For example, about 7 percent of boys who received vouchers were depressed and had post traumatic stress disorder (PTSD), compared to about 4 percent of those who didn't receive additional assistance.

The boys whose families received vouchers were also more likely to have post traumatic stress disorder (PTSD) and behavioral problems than those in the comparison group.

The rates of PTSD among boys in the study, about 4.4 percent, are similar to those found in studies of soldiers returning from combat, the researchers note.

In contrast, about 7 percent of girls whose families received vouchers were depressed, versus about 11 percent in the comparison group. The girls who got vouchers were also less likely to have behavioral problems.

Dr. Neal Halfon wrote in an editorial that boys may not benefit from moving to better neighborhoods without other supports, because they have fewer social skills.

For girls, the reduction in depression and behavioral problems compared to girls in the old neighborhood may be due to moving into areas that are less sexually coercive, wrote Halfon, who is with the Center for Healthier Children, Families and Communities at the David Geffen School of Medicine at the University of California, Los Angeles.

Kessler said the key is to find a way to utilize HUD's resources to allow people not to just find new homes but also better integrate them into the community.