New research has linked attention deficit hyperactivity disorder (ADHD) and conduct disorder to increased alcohol and tobacco use in young adolescents.

ADHD is a psychiatric disorder of the neurodevelopmental type in which there are significant problems of attention, hyperactivity, oracting impulsively that are not appropriate for a person's age. Conduct disorder is a behavioral and emotional disorder marked by aggressive, destructive or deceitful behavior.

"Early onset of substance abuse is a significant public health concern," William Brinkman, the study's lead author, said in a statement. "Adolescents who use substances before the mid-teen years are more likely to develop dependence on them than those who start later. This is why prevention is so important."

For the study, researcher collected and analyzed data from more than 2,500 teens between the ages of 12 and 15. The data came from the 2000-2004 National Health and Nutrition Examination Survey (NHANES), which is a nationally representative sample of the United State population designed to collect information about health.

Teens with a diagnosis of ADHD and conduct disorder had a three- to five-times increased likelihood of using tobacco and alcohol and initiated use at a younger age than those who had neither disorder. Having ADHD alone was associated with an increased likelihood of tobacco use but not alcohol use.

The findings are detailed in the journal Drug and Alcohol Dependence.