According to a new study by University of Florida researchers, ADHD is linked to earlier illicit drug use in teens and young adults. The use of both depressants and stimulants starts earlier in life for those with ADHD.

According to US News, “In the study, Dunne’s team looked at questionnaires completed by more than 900 adults who had used illicit drugs in the past six months. Of those, 13 percent said they had been diagnosed with ADHD.

“On average, those with ADHD began using alcohol at age 13, about 1.5 years before those without ADHD. Among participants who injected cocaine, those with ADHD began doing so at an average age of 22, two years earlier than those without ADHD.”