Concordant alcohol and marihuana use in women.

Alcohol and marihuana use are common among both sexes, but systematic data on drug use patterns by women previously have been unavailable. This report describes the first prospective study of alcohol and marihuana consumption patterns in women, and examines factors that promote or maintain concurrent use. Thirty healthy adult women (mean age = 26.4 years) completed daily questionnaires for 3 consecutive menstrual cycles. Subjects recorded quantities and times of alcohol and marihuana consumption, episodes of sexual activity, and occurrence of unusual life events. Temporal variables significantly affected both alcohol and marihuana consumption. Marihuana use occurred earlier in the day than alcohol use. Significantly greater marihuana consumption and more concordant alcohol and marihuana use occurred on weekends. Older subjects (26 to 30) exhibited more concordant alcohol and marihuana use than younger subjects (21 to 25). Significant differences in alcohol use also distinguished heavy from light marihuana smokers. Neither sexual activity nor unusual events were associated with concordant alcohol and marihuana consumption in all subjects.