the potential relationship between alcohol use and marijuana use. The correlations for number of alcoholic drinks and number of smokes were not significant for parametric (r = .321; p = .243) or nonparametric (Kendall’s tau_b = .216; p = .313; Spearman’s rho = .281; p = .310) analyses, suggesting no relationship between alcohol and marijuana use. The findings reported here highlight the importance of examining both the frequency of use and overall level of marijuana present, and suggest a direct relationship between smoking marijuana and BOLD signal changes within specific brain regions for both masked affective tasks, which appear to be independent of other factors, including alcohol use. Finally, the findings are particularly noteworthy, as none of the chronic, heavy marijuana subjects were acutely intoxicated or “high” at the time of the scan and had been abstinent for a minimum of 12–16 hours, and are therefore not likely to reflect acute effects of the drug.
