Tobacco smoking in marijuana-dependent outpatients.

PURPOSE: Among marijuana-dependent individuals, approximately 50% smoke tobacco. These individuals are exposed to increased risks of respiratory and other health problems. The current study examined whether tobacco smoking among marijuana-dependent individuals is also associated with increased psychosocial and substance abuse problems.
METHODS: Marijuana-dependent individuals (N=174) seeking treatment for marijuana problems completed a 2-3 h assessment. Current tobacco smokers were compared to ex-smokers and never smokers on demographic, psychosocial, and substance use characteristics, and treatment outcome. In addition to univariate comparisons, multivariate analyses using multinomial logistic regression were conducted to control for the correlated nature of the predictor variables.
RESULTS: Current tobacco smokers earned less income and reported histories of more alcohol problems than never smokers and had fewer years of education, more legal problems, more psychiatric symptoms, and an earlier age of marijuana initiation than ex- and never smokers. Over the course of treatment, current tobacco smokers had significantly fewer marijuana-negative urine specimens and fewer weeks of continuous marijuana abstinence than ex-smokers. IMPLICATIONS: Current tobacco smokers appear to represent a subgroup of marijuana-dependent individuals who have increased psychosocial problems compared to ex- and never smokers and may not respond as well to treatment than ex-smokers.