RecruitingPhase 1Behavioural interventionSex Differences in the Response to Abstinence From Alcohol.In laboratory animals, repeated cycles of abstinence from and return to alcohol drinking can lead to changes in alcohol intake. In a study of the effect of abstinence on drinking in humans, the investigators found evidence that abstinence affects drinking differently in women compared to men. In the present study, the investigators propose to study how men and women respond to abstinence, and whether this information can be used to improve intervention and prevention strategies.