Substance Use among Sexual Minority versus Heterosexual Women: A Systematic Review of Population-Based Studies

Objectives: Sexual minority women (SMW; i.e., lesbians and bisexual women) appear to use both licit and illicit substances more than heterosexual women, but previous reviews have relied on data from small convenience samples. We conducted a systematic review of population-based studies comparing substance use among SMW versus heterosexual women across six overlapping categories.

Methods:  We searched PubMed for population-based, peer-reviewed, English-language studies published 3/2009 – 6/2013 that statistically compared at least one of six categories of substance use among predominantly adult women by sexual orientation--i.e., heterosexual women versus (a) lesbians, (b) bisexual women, or (c) lesbians and bisexual women combined.

Results: Nineteen of 1,826 studies were included providing 73 total comparisons. Evidence of disparities among SMW (i.e., significant adjusted odds ratios) was strongest for tobacco use (19 of 20 comparisons), problematic alcohol use (20 of 24), and problematic drug use (12 of 14).  Less consistent evidence for SMW disparities emerged when comparing cannabis use, alcohol dependence, and drug dependence. Some evidence suggested greater drug dependence disparities among lesbians compared to heterosexual women.

 Conclusions: Population-based estimates of substance use appear to be higher among SMW women than heterosexual women, but the findings vary by substance use category. Understanding the implications of findings for problematic drug use is limited as illicit substances (excluding cannabis) were pooled for this category, potentially hiding important specific drug use patterns. Overall, disparities were more evident for problematic drug use than drug dependence among SMW, though lesbians in particular were more likely to experience drug dependency.