The researchers will study 100 families over three years, each with a child (proband) between the ages of 12-17, with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnosis of ADHD. The researchers hypothesize smoking will be familial and ADHD probands with a family history of tobacco use will be at increased risk for early initiation and persistence of smoking, compared to ADHD probands with no family history of tobacco use.

As Attention Deficit Hyperactivity Disorder (ADHD) is a documented risk factor for smoking in adolescents, and as theoretical considerations suggest that ADHD and tobacco use may share common underlying mechanisms, the proposed study looks to examine the association between smoking and ADHD. Since both ADHD and smoking are known to be familial disorders, one approach to examine the nature of the association between the two disorders is to conduct a familial risk analysis comparing ADHD youth who smoke and ADHD youth who don't smoke. Another approach is to conduct a genetic study, to identify candidate genes associated with nicotine abuse and dependence in ADHD youth and relatives.

This study includes:

1. assessment of psychopathology and substance use/dependence,
2. assessment of the family environment, and
3. assessment of molecular genetics in 100 families with at least one child (proband) between the ages of 12-17 with a DSM-IV diagnosis of ADHD.

Inclusion Criteria:

• First-degree relative between the ages of 6-55 years of a family member (proband) between the ages of 12-17 with the DSM-IV diagnosis of ADHD

First-degree relative between the ages of 6-55 years of a family member (proband) between the ages of 12-17 with the DSM-IV diagnosis of ADHD