Substance use and related problems among U.S. women who identify as mostly heterosexual

Background: We used data from a nationally representative sample to compare substance use outcomes among adult women who identified as mostly heterosexual with those who identified as exclusively (only) heterosexual. Method: We analyzed data from mostly heterosexual women and only heterosexual women in Wave 5 (2001) of the National Study of Health and Life Experiences of Women (weighted n = 1085). Results: Mostly heterosexual women were significantly more likely than only heterosexual women to report every alcohol-related outcome included in our analyses except lifetime treatment. Odds of lifetime and past-year marijuana and cocaine use showed larger differences, with mostly heterosexual women nearly four times as likely as only heterosexual women to report lifetime cocaine use and five times as likely to report past-year use. Conclusions: We recommend that researchers use measures of sexual identity that include more nuanced response options, and that health care providers learn about the existence, large numbers, and risk/protective factors associated with substance use patterns of mostly heterosexual women.