Smoking rates are higher for persons with attention-deficit/hyperactivity disorder (ADHD) when compared with the general population in clinical studies. Persons with ADHD have been shown to begin smoking at an earlier age and are more apt to become regular smokers. Also, adult smokers with ADHD have more difficulty with smoking cessation than do persons in the general population. To date, all of the studies that have evaluated the relationship between ADHD and smoking have used clinical samples of persons diagnosed with or at high risk of developing ADHD. Kollins and associates assessed the relationship between smoking and the number of self-reported inattentive and hyperactive/impulsive behaviors in a population-based sample of young adults with ADHD.
Participants drawn from wave III of the National Longitudinal Study of Adolescent Health responded to three in-home surveys on separate occasions from 1995 to 2002. The participants were divided into two groups based on their self-reported smoking status: “never-regular” and “ever-regular” smokers. Two additional smoking variables were age at onset for regular smokers and number of cigarettes smoked in the past 30 days. Respondents were asked to recall nine inattentive and eight hyperactive/impulsive symptoms from when they were five to 12 years of age and rate their frequency on a four-point Likert scale (never or rarely, sometimes, often, and very often). For a symptom to be considered present, the response had to be often or very often. The main outcome measure was the relationship between ADHD symptoms and the likelihood of being a regular smoker. Secondary outcomes included the extent to which ADHD symptoms predicted the age at smoking onset and number of cigarettes smoked among persons who regularly smoked.
The total study population was 15,197 and the mean age of participants was 15.65 years for wave I, 16.22 years for wave II, and 22.96 years for wave III; 49.5 percent were male and 37.1 percent were nonwhite. Of the sample population, 38.6 percent were classified as “ever-regular” smokers. When comparing the number of self-reported inattentive and hyperactive/impulsive symptoms, a linear relationship was noted between the number of symptoms and smoking outcome measures. If respondents had all nine inattentive symptoms, their odds ratio for smoking was 3.93 (95 % confidence interval [CI], 2.35 to 6.56). Positive responses to all eight hyperactive/impulsive symptoms resulted in an odds ratio of ever smoking regularly of 2.92 (95 % CI, 1.75 to 4.87). When the authors controlled for demographic variables and conduct disorder symptoms, the linear relationship between the number of reported symptoms and rate of smoking persisted. Therefore, as the number of ADHD symptoms increased, the age at onset of smoking decreased and the number of cigarettes smoked increased.
The authors conclude that self-reported ADHD symptoms are associated with adult smoking. They add that these symptoms also are associated with an earlier age at onset of smoking and a higher number of cigarettes smoked. Further research is needed to develop smoking cessation strategies for persons who have ADHD symptoms.