Background: Several studies have reported higher smoking rates among adolescents with externalizing disorders (attention-deficit hyperactivity disorder and conduct disorder) as compared to healthy controls. Objective: To follow the association between childhood externalizing disorders and smoking during development, to determine the type of problems most strongly related to later tobacco use, and to control for the influence of covarying factors. Methods: Participants were from a longitudinal study of a birth cohort of 384 children born with different perinatal and psychosocial risks. Standardized assessments of behavioral disorders between 2 and 11 years and of tobacco use at age 15 were obtained. Results: 15-year-olds with externalizing disorders between 2 and 11 years reported higher tobacco use than those without a history of disorder. This association could be followed back into early childhood and held up even after controlling for covariates. Conclusions: The findings suggest that childhood externalizing disorders may represent an independent risk factor for elevated tobacco use in adolescence
The present study aimed to examine the extent to which the co-occurrence of ADHD and smoking in adolescents could be attributed to common genetic, environmental and psychopathological factors. Data are from an ongoing prospective study of the outcome of early risk factors. At age 15 years, 305 adolescents completed self-report questionnaires measuring tobacco consumption and deviant peer affiliations. Lifetime psychiatric diagnoses were obtained using standardized interviews. DNA was genotyped for the dopamine D4 receptor (DRD4) gene exon III polymorphism. Adolescents with a lifetime diagnosis of ADHD displayed significantly higher smoking activity than non-ADHD controls. A major component of this association could be accounted for by deviant peer affiliations and the comorbidity with oppositional-defiant and conduct disorder, while a minor part was attributable to DRD4 in males but not in females. These findings suggest that the association of ADHD with smoking relies on risk factors shared by the two behaviors.