Influence of Tobacco Use on Cannabis Use

Cannabis smokers who also smoke tobacco cigarettes have markedly higher rates of cannabis relapse relative to those who do not use tobacco. There is a clear need to develop and evaluate interventions for dual tobacco and cannabis users. The investigators of this study have previously shown that the co-use of tobacco cigarettes contributes to the maintenance of daily cannabis use, and that age of cigarette onset is a critical predictor of treatment outcome. Short-term tobacco cessation may suffice in altering cannabis relapse rates in later-onset cigarette smokers, while a longer period of tobacco cessation may be needed for earlier-onset smokers. In the current study, a human laboratory model will be utilized to determine whether cannabis relapse varies as a function of tobacco cessation duration and age of tobacco use onset.

Inclusion Criteria: * Males and non-pregnant females aged 18-60 years old * Use cannabis * Smoke tobacco cigarettes * Medically and psychologically healthy Exclusion Criteria: * Regular drug use other than cannabis * Current pregnancy/lactation