Children born to mothers who are poor and who had gestational diabetes are 14 times more likely to have attention deficit-hyperactivity disorder (ADHD), according a report published in the Archives of Pediatrics and Adolescent Medicine.

Over 200 children were included in the new study. Mothers who had diabetes while pregnant or were poor were twice as likely to have children with ADHD, researchers found. But when the two risk factors were combined, the risk of ADHD skyrocketed.

Exactly why these factors are linked to ADHD is unknown.

Poor women tend to eat less healthy foods, which boosts their risk of diabetes, notes study senior author Dr. Jeffrey M. Halperin, a professor of psychology at Queens College in New York.

The study highlights that ADHD has multiple causes, said Dr. Jon A. Shaw, director of child and adolescent psychiatry at the University of Miami School of Medicine. “It is important to recognize early risk factors for ADHD because this gives us the chance to develop strategies to prevent it.”

ADHD affects about 10 percent of children between the ages of 4 and 17 in the United States, according to the Centers for Disease Control and Prevention. Symptoms of ADHD include difficulty focusing, impulsive behaviors, and hyperactivity.