Former foster children are almost twice as likely to suffer from Post-Traumatic Stress Disorder (PTSD) as U.S. war veterans, according to a study released Wednesday by the Harvard Medical School (HMS), the University of Michigan and Casey Family Programs.

The Northwest Foster Care Alumni Study, which traced 659 alumni of the Oregon and Washington state welfare agencies, found that former foster children also have low completion rates for post-secondary education and lower employment rates compared to the general population.

According to the study, one in four alumni had experienced PTSD in the previous 12 months and more than half had experienced at least one mental health problem such as depression, social phobia, or panic syndrome.

These high rates of mental health problems may also affect rates of educational and occupational success.

Although over four in five alumni had completed high school, the percentage completing a bachelor’s degree—1.8 percent—lagged far behind the 24 percent of the general population who graduated from college.

The employment rate of former foster children was 80.1 percent compared with 95 percent for those aged 20-34 in the general population. A third had household incomes at or below the poverty level.

Peter J. Pecora, Senior Director of Research Services at Casey Family Programs—an organization promoting advances in child-welfare practice and policy—stressed that the frequent placement changes and lack of permanent support guarantees often faced by foster children contribute to feelings of anxiety and social instability.

“The first placement should be the last placement,” said Pecora. “The average age a person leaves home is 25. People are taking longer to reach adulthood, finish school and have children. Given that backdrop, why would we expect that someone who has faced the challenges of the welfare system to be fully self-sufficient by age eighteen?”

According to the study, 65 percent of children in foster care experience seven or more school changes from elementary to high school. Following the age of 18, the foster care system no longer has an obligation to provide foster children with family placements.

Professor of Health Care Policy Ronald Kessler, a co-author of the project, says foster children’s greater likelihood of mental health risks is primarily based upon the experiences, such as neglect and abuse, that children face before entering the foster system.

But he also contends that there is a need for more mental health treatment within the current foster care system.

“This currently occurs for kids who have acting-out problems, like violence or substance disorders or [Attention Deficit and Hyperactivity Disorder], but not nearly as much for kids with more silent mental health problems like depression or PTSD,” Kessler wrote.

The study suggests that states should not only help kids within the foster care network, but also provide assistance to its alumni. Beyond lengthening placements and providing more social service workers to foster children, the provision of social and financial support for alumni may counteract future mental health risks.