Predictors of marijuana use among married couples: the influence of one's spouse.

With the transition into marriage, marijuana and other substance use tends to decline; however, this is not true for all individuals. The objective of this work was to examine the impact of premarital individual and partner psychological health and substance use behaviors on the likelihood of using marijuana over the first four years of marriage. Couples' (N=634) marijuana use, other substance use, and psychological variables were assessed at the time they applied for their marriage license and then again at the first, second and fourth anniversaries. Generalized estimating equation models were used to estimate the risk for using marijuana over the first four years of marriage after controlling for the natural decrease in risk associated with time and other relevant sociodemographic variables. Smoking prior to marriage and heavy alcohol use was associated with an increased risk for using marijuana over the first four years of marriage for both husbands and wives. After considering the impact of time and individual risk factors, a spouse's use of marijuana prior to marriage was a strong predictor of increased risk for marijuana use during the first four years of marriage.