Legal protection for undocumented immigrants can alleviate symptoms of mental illness in their children, a new study shows.

Chris Russell/Associated Press

Children of legally protected immigrants less likely to suffer mental illness

Five years ago, U.S. President Barack Obama signed an executive order that allowed young, unauthorized immigrants who arrived in the country as children to work, go to school, and get a driver’s license without fear of deportation. More than 780,000 people under 31—so-called “dreamers”—signed up for the program, known as Deferred Action for Childhood Arrivals (DACA). Now, a study shows for the first time that even the temporary protection DACA provides to dreamer parents can rapidly boost their children’s mental health, sharply reducing the rate of several mental disorders.

Even “a relatively small change in a parent’s migratory status can significantly improve a child’s well-being,” says Cécile Rousseau, a child psychiatrist at Montreal Children’s Hospital in Canada who was not involved with the work.

The researchers analyzed emergency Medicaid claims data from 5653 unauthorized immigrant mothers from Oregon, all born between 1980 and 1982. DACA’s arbitrary enrollment criteria, which only allow immigrants born after 15 June 1981 to apply, created control and treatment groups similar to those used to test the efficacy of drugs in clinical trials.

Combined, DACA eligible and ineligible mothers gave birth to 8610 children between 2003 and 2015. All are legal U.S. citizens. Jens Hainmueller, lead author of the study and a political scientist at Stanford University in Palo Alto, California, and colleagues looked at the childrens' medical records, focusing on two distinct types of psychiatric diagnosis. The first category, anxiety disorders, has a strong genetic component and these disorders may arise with or without an external cause. The second category, adjustment disorders, are specifically driven by external stressors, such as poverty or the fear of losing a parent.

Before DACA, there was no discernable difference in mental illness diagnoses between the children of eligible and ineligible mothers. Once DACA protections came into effect, however, diagnoses in the children of protected mothers dropped by about half, from 7.9% to less than 4%, the team reports today in Science. The greatest drop was in adjustment disorders, which suggests that the improvement stemmed from a change in the children’s stress levels, not from a genetic or other internally driven factors, Hainmueller says.

It is notoriously difficult to establish the effects of immigration policy, in part because undocumented immigrants often fear exposure and are reluctant to participate in research, Rousseau says. “This is a very important paper,” because the authors were able to glean sufficiently large amounts of data from the Oregon Medicaid system to achieve statistical significance, and could use the control group to rule out confounding factors such as immigrants’ income, education levels, and access to health care, she says.

Given that Medicare data from other states are available, the approach could be used more broadly to measure the health impacts of immigration policy nationwide, says Tom Wong, a political scientist at the University of California, San Diego. He suspects the study underestimates the mental health benefits of legal protection for a child’s family members, because it focuses only on mothers, not fathers, siblings, or grandparents. “If we limit the study to children and their mothers, we’re not getting the full picture of what households are concerned about,” he says.

The high economic and social costs of early mental illness compound as children get older; for example, adjustment disorders in childhood are associated with poor school performance and increased reliance on social welfare, Heinmeuller says. “Our country is wrapped up in a heated ideological debate about whether we should recall DACA or keep it,” he says. Many predict the Donald Trump administration will decide the policy’s fate in September. “Regardless of where you come down in these debates, you need to take a broader calculus into account, and look at the consequences DACA has for children and their future success or failure.”