Young adults with attention deficit hyperactivity disorder (ADHD) are at high risk
of substance use (SU). The aims of the current study were: 1) to examine the use of alcohol,
tobacco, marijuana and other illegal drugs by adults with and without ADHD; 2) to compare
the oppositional, conduct, anxiety, depression, sleep and antisocial personality symptoms of
ADHD adults with SU and ADHD adults without SU; 3) to examine the ability of ADHD symptoms
and conduct problems to predict SU.