The study was approved by the National Institute on Drug Abuse Institutional Review Board. Parents provided consent for their adolescents to participate, and each adolescent signed an assent form after the study was explained fully and especially all questions answered. Table 1. Demographic information and primary variables of interest across externalizing and nonexternalizing groups Data collection was undertaken as part of a larger study with two main goals: (a) smoking cessation treatment trial (Moolchan et al., 2005) and (b) the relationship between externalizing disorders and treatment resistance (Bagot et al., 2007). The latter study showed that severity of externalizing symptoms predicted continued smoking despite participation in cessation treatment.

The findings from the present study extend to the contribution of psychiatric diagnoses of ODD, ADHD, and CD to the development of tobacco dependence as indexed by changes over time in the number of cigarettes smoked per day over the 2 years following the first puff. Instruments and procedures After a brief phone screen, preeligible participants were invited to the clinic for two assessment visits. During the screening visits, participants underwent a physical examination and provided information about their family history and current or past psychiatric disorders. Psychiatric diagnoses were based on the semistructured, computerized version of the Diagnostic Interview for Children and Adolescents (Reich, 2000), which was administered by a trained interviewer.

The Child Behavior Checklist for parental report (Achenbach, 1991) and Youth Self-Report for adolescent self-report (Achenbach & Dumensi, 2001) were used to quantify severity of externalizing symptomatology. Adolescents with and without an externalizing disorder (ADHD, ODD, or CD) were included in the present analysis. Individuals diagnosed with a mood or an anxiety disorder, psychosis, or abuse Batimastat of substances other than tobacco and marijuana were excluded. Developmental smoking trajectories, cigarettes per day, and FTND scores were obtained through self-report at the time of treatment request. The FTND is a widely used six-item questionnaire that assesses tobacco dependence and has well-established psychometric properties (Hendricks, Prochaska, Humfleet, & Hall, 2008). Adolescents also provided information about their smoking history (e.g., ��How old were you when you smoked your first cigarette?,�� ��How old were you when you took your first puff?,�� and ��At what age did you begin smoking daily?��).