"Comorbidity between ND and psychiatric disorders characterized these adolescent smokers. Nicotine dependent adolescents had higher rates of anxiety, mood, disruptive, and multiple disorders than non-dependent smokers. The study elucidates these associations. Foremost, comorbidity between ND and psychiatric disorders in adolescence results from the fact that psychiatric disorders increase the risk of ND, controlling for common underlying factors. ND increases the risk of psychiatric disorders to a much weaker extent. This partially is due to the fact that, on average, psychiatric disorders onset ND by at least two and a half years, as reported by others [32,50], and in most cases psychiatric disorders precede ND. With control for covariates, we demonstrated a bidirectional association between disruptive disorder and ND, a unidirectional association between anxiety and ND, and no association between mood disorder and ND. Comorbidity of ND with mood disorders is explained by a common etiology."


Pamela C. Griesler, Mei-Chen Hu, Christine Schaffran, and Denise B. Kandel, "Comorbid Psychiatric Disorders and Nicotine Dependence in Adolescence," Addiction, 2011 May; 106(5); 1010-1020. doi:10.1111/j.1360-0443.2011.03403.x