Cigarette smoking has been identified as an independent risk factor for many human diseases. However, the association between cigarette smoking and illegal drug use has not been thoroughly investigated. The 1994 National Household Survey on Drug Abuse was analyzed to clarify whether cigarette smoking has any effect on the initiation of illegal drug use. Data from 17,809 respondents completing the 1994 questionnaire were analyzed. Logistic regression analyses were performed with the use of statistical package SU-DAAN, taking into consideration the multistage sampling design. The results show that those who had smoked cigarettes were far more likely to use cocaine, heroin, and marijuana. The associations were consistent across age strata and remained after adjusting for race and gender. This study suggests that cigarette smoking may be a gateway drug to illegal drug use. References