Substantial progress in the field of cigarette smoking prevention in youths has been made during the past few years. Researchers have focused on the prevention of cigarette smoking for several reasons. First, cigarette smoking is a major risk factor for such chronic diseases as coronary heart disease, cancer, and emphysema. Second, cigarette smoking is the most widespread form of drug dependence in our society. Third, cigarette smoking occurs toward the very beginning of the developmental progression of substance abuse and consequently is generally regarded to be one of the so-called 'gateway' substances.