Male–female differences in the risk of progression from first use to dependence upon cannabis, cocaine, and alcohol

IntroductionWe extend prior reports about the risk of dependence on specific drugs by providing developmental-specific risk estimates for progression from first use to meeting criteria for DSM-III-R dependence upon cannabis, cocaine, or alcohol, as well as male–female differences.MethodsThe data are from the National Comorbidity Survey, with a national probability sample of persons 15–44 years old in the United States, which included many respondents who used cannabis, cocaine and alcohol on at least one occasion (n = 3558, 1337, and 6149, for cannabis, cocaine, and alcohol, respectively). Survival analysis procedures provided cumulative risk estimates of progression from first use to dependence upon each drug.ResultsThe estimated risk of cannabis dependence among male cannabis users was 1% in the first year after first use, and reached a peak at 4% per year 2 years later, before declining. In contrast, the estimated risk of cannabis dependence among female cannabis users remained at 1% per year for 3 years, without the peak. For both male and female cocaine users, the estimated risk for developing cocaine dependence was 5 to 6% within the first year after first use. Thereafter, the estimated risk declined from the peak value, with a somewhat faster decline for females in the next 3 years after first use. For alcohol, the estimated risk period extended for many years after the first drink, with female drinkers becoming alcohol dependent at a rate of about 1% per year; with somewhat higher risk for male drinkers. For both male and female drinkers, the period of risk for developing alcohol dependence extended for a span of more than 20 years since first use; for cannabis and cocaine, the estimated period of risk was much shorter.CommentThere are male–female differences in the risk of becoming cannabis dependent during the first several years after initiation of cannabis use, less pronounced male–female differences for alcohol, and relatively smaller male–female differences for cocaine. These results should interest scientists whose focus is upon the origins of male–female differences in the occurrence of drug dependence.