Current models of nicotine dependence: what is known and what is needed to advance understanding of tobacco etiology among youth.

Youth smoking has risen dramatically during the last 5 years, leading one to the conclusion that prevention interventions have not been particularly effective. This paper provides an examination of features that define adult nicotine dependence and argues that these features need to be considered in any studied examination of youth etiology and development to nicotine dependence. We review the historical context for the concept of nicotine dependence, features that define the concept and current models of substance dependence more generally. Recommendations for future research are provided.