Adolescents who have attention-deficit/hyperactivity disorder are much more likely than peers without the condition to become teenaged parents, according to a large Danish study. In the 12-15 age group in particular, girls with ADHD were three and a half times more likely and boys were almost two and a half times more likely to become parents in their teen years. “We were expecting to find an increased risk, but not of this magnitude,” said lead study author Dr. Soren Dinesen Ostergaard, of Aarhus University Hospital in Denmark.