LAUSR

335 Several associations between childhood gender non­ con­ formity and mental health problems remained statistically sig­ nificant in analyses stratified by categories of sexual identity. Among heterosexual participants, mental health challenges were reported consistently more often by childhood gender non­ conforming than conforming individuals, most notably so for self­ harm (women: aOR=2.11, 95% CI: 1.79­ 2.48; men: aOR=1.81, 95% CI: 1.46­ 2.25). Using childhood gender conforming heterosexual peers as ref­ erence, childhood gender conforming homosexual participants generally did not exhibit statistically significantly increased odds of mental health problems. In contrast, childhood gender non­ conforming homosexual participants had elevated odds of most mental health problems, with particularly high odds for suicidal thoughts/attempts (women: aOR=3.32, 95% CI: 1.89­ 5.82; men: aOR=2.62, 95% CI: 1.75­ 3.91) (see also supplementary informa­ tion). For bisexual participants, odds of several mental health prob­ lems were increased among both childhood gender conforming and non­ conforming individuals when compared to the refer­ ence group of childhood gender conforming heterosexuals. Par­ ticularly elevated odds were observed for self­ harm (women: aOR=3.12, 95% CI: 2.06­ 4.71; men: aOR=5.27, 95% CI: 2.71­ 10.25) and suicidal thoughts/attempts (women: aOR=3.14, 95% CI: 2.12­ 4.65; men: aOR=2.33, 95% CI: 1.28­ 4.25) among gender non­ conforming bisexuals (see also supplementary information). With approximately one­ in­ five study participants recalling difficulties living up to other people’s gender­ specific norms and expectations as a child or young person, our nationally rep­ resentative findings demonstrate that childhood gender non­ conformity is by no means a rare phenomenon restricted to spe­ cific subsets of the general population. While proportions of non­ cisgender and non­ heterosexual individuals reporting childhood gender non­ conformity are clearly higher than corresponding proportions among cisgender and heterosexual peers, the vast majority of childhood gender non­ conforming people in the gen­ eral population are cisgender, heterosexual individuals. Importantly, we document that childhood gender non­ con­ formity is linked to a considerably increased burden of mental health problems among both women and men, and among het­ erosexual, homosexual and bisexual individuals alike. These find­ ings should raise awareness about the elevated burden of mental health problems among individuals with recalled childhood gen­ der non­ conformity, and stimulate initiatives to increase societal acceptance of gender diversity and eliminate bullying and vio­ lence against gender atypical children and adolescents.