Sexual orientation measurement, bisexuality, and mental health in a sample of men who have sex with men in Vancouver, Canada.

This cross-sectional study used a validated index (i.e., Hospital Anxiety and Depression Scale) to measure anxiety and depression (caseness score: ≥8) among men who have sex with men recruited via respondent-driven sampling in Vancouver, Canada (n=774), and investigated whether differences in mental health outcomes varied by sexual orientation measure (i.e., identity, attraction, behavior). Of the sample, 15.5% identified as bisexual, 33.4% reported any bisexual attraction, and 22.7% reported any bisexual sexual activity. More bisexual than gay men met the case definition for anxiety and depression, across all sexual orientation measures. In adjusted multivariable models, bisexual men had higher odds of anxiety by attraction and identity and higher odds of depression by identity. Findings highlight the value of measuring multiple sexual orientation dimensions in surveys and routine surveillance, and the need to ensure sexual minority groups and sexual orientation dimensions are not considered commensurate for mental health prevention and treatment.