Abstract
AIM: Despite evidence on higher risk for homelessness and worse mental health in sexual minority (SM) adolescents, no study has examined these associations using nationally-representative data in the UK. This study examined inequalities in the prevalence of past homelessness by sexual identity, and whether rates of poor mental health and health-risk behaviours (HRBs) differ by sexual identity and past homelessness in adolescents. METHODS: This cross-sectional study used data from the age 17 sweep of the UK-wide Millennium Cohort Study (N = 10,232, 51% female, 21% SM). Mental health was assessed using the Strengths and Difficulties Questionnaire (SDQ) emotional symptoms subscale for depression and anxiety, and self-reported actions of self-harm, attempted suicide, sleep quality and doctor-diagnosed depression. HRBs were measured using six variables, including regular smoking and antisocial behaviour. Associations between sexual identity (heterosexual, mainly heterosexual, bisexual and gay/lesbian) and past homelessness were examined using multivariable logistic regression. Associations between past homelessness and mental health and HRBs, and whether these differed by sexual identity were examined using multivariable logistic regression with appropriate interactions between the homeless and sexual identity variables. Models were adjusted for sex, parental income and ethnicity. RESULTS: Bisexual (adjusted-OR 2.92, 95% CI: 1.47–5.82) and gay/lesbian (adjusted-OR 1.87, 0.53–6.56) adolescents had higher odds for past homelessness compared to heterosexual peers. Prevalence of self-harm (homeless bisexual/gay/lesbian and heterosexual: 85% and 39% respectively, not homeless bisexual/gay/lesbian and heterosexual: 55% and 18% respectively) and attempted suicide (homeless bisexual/gay/lesbian and heterosexual: 52% and 22% respectively, not homeless bisexual/gay/lesbian and heterosexual: 18% and 5% respectively) were significantly higher in individuals with past homelessness with the highest rates among SM youth. Similar pattern of findings was observed with regular smoking and antisocial behaviour. CONCLUSIONS: SM individuals are more likely to experience past homelessness. Past experiences of homelessness are associated with worse current mental health and HRBs regardless of sexual orientation. However, greater proportions of SM adolescents with past experiences of homelessness reported worse mental health and some HRBs compared to heterosexual peers with the same experience. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-025-25429-7.