Prospective study of tobacco smoking and substance dependencies among samples of ADHD and non-ADHD participants.

This study focused on an audience at high risk for heavy use of licit and illicit substances: young adults who as children had attention-deficit/hyperactivity disorder (ADHD). The participants in this study were part of a longitudinal study of the life histories of 492 children, one third of whom were identified as hyperactive in 1974 and whose childhood symptom ratings and medical histories were used to establish Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised; DSM-III-R) ADHD diagnoses (American Psychiatric Association, 1987). The objectives of the study centered on describing (a) developmental history of tobacco use among ADHD and non-ADHD participants in a longitudinal sample, (b) the characteristic adult patterns of tobacco use from early adolescence through early adulthood, and (c) the relationship between ADHD status and tobacco and substance dependence outcomes. Adult data were obtained for 81% of the original 492 participants (77% of the ADHD and 86% of the controls). Lifetime and current tobacco use were assessed from child, adolescent, and adult data, yielding eight measures of smoking status. The study showed that participants with and without ADHD did not differ in age of initiation to smoking, but there was a significant difference in the age they began smoking regularly. By age 17, 46% of all participants with ADHD, as contrasted with 24% of the age-mate controls, reported smoking cigarettes daily. In adulthood, the proportion of participants with ADHD who were current smokers (42%) continued to exceed that of the age-mate controls (26%). Among current adult smokers, 35% with ADHD smoked daily as compared to 16% of the age-mate controls. There were significantly different lifetime tobacco dependence rates--40% compared to 19% for age-mate controls. The rates for cocaine dependence were 21% for participants with ADHD and 10% for age-mate controls. We reported a significant difference in rates of daily smoking and tobacco dependence for those with ADHD who had used stimulant medication in childhood in contrast to controls. Results were interpreted to support a possible link between ADHD treatment histories and levels of tobacco smoking and tobacco dependence in adulthood.