Alternatively, at comparable levels of predisposing factors, women who initiated drinking at 15-17 years of age might have been at increased risk for the incidence of dependence relative to men because older romantic partners exposed some of them to more regular drinking occasions on which greater amounts of alcohol were consumed, setting in motion a process of heavier drinking that culminated in a greater incidence of dependence in adulthood. This explanation is consistent with the near-significant increased risk of the incidence of drinking despite adverse physical/psychological consequences among women, consequences that might result from a greater volume of ethanol intake, as well as with the fact that there was no gender interaction with age at first drink after adjusting for consumption level. Indirect support for this interpretation was found by Castillo Mezzich et al. (1999), who reported more adult male sexual partners among adolescent girls with substance use disorders.
