Massachusetts General Hospital researchers report in the Journal of Pediatrics they found that individuals with more ADHD-related symptoms -- even those who don't have the full syndrome -- are at greater risk of becoming dependent on nicotine than those with fewer symptoms.

"Knowing that ADHD increases the risk of more serious nicotine addiction stresses the importance of prevention efforts aimed at adolescents and their families," study leader Dr. Timothy Wilens said in a statement.

Participants were taken from two long-term studies -- one in boys and the other in girls -- that analyzed a variety of factors in children and adolescents with ADHD compared with a matched control group.

Of the 80 participants with ADHD and 86 controls -- ages 15 to 25 -- 69 percent of participants with ADHD had ever smoked and 41 percent were current smokers, compared to 44 percent of controls had ever smoked and 17 were currently smoking.

Smokers with ADHD began using tobacco more than a year sooner than did control group members.