Associations between autism, gender dysphoria and gender incongruence: insights from the Swedish Gender Dysphoria Study (SKDS)

BACKGROUND: A higher prevalence of autism spectrum disorder (ASD) and autistic traits among transgender and gender diverse individuals compared to the general population has been reported. However, inconsistent findings and methodological limitations have been noted in the literature. This study aims to investigate the prevalence of ASD diagnoses and autistic traits among individuals with gender dysphoria compared to a cisgender group and to explore associations between autism and self-reported levels of gender incongruence in individuals with gender dysphoria. METHODS: This study is part of the Swedish Gender Dysphoria Study. ASD diagnoses were retrieved from the national patient registers. Autistic traits were assessed using the Ritvo Autism and Asperger Diagnostic Scale-14 (RAADS-14) and Autism Spectrum Quotient (AQ). Gender incongruence was evaluated with the Transgender Congruence Scale. Associations with gender incongruence were examined with linear regression analysis. RESULTS: Participants with gender dysphoria, regardless of birth-assigned sex, had a higher prevalence of ASD compared with cisgender participants (RR = 7.8; 95 % CI = 3.9, 15.3). The gender dysphoria group also scored higher on both the RAADS-14 (MD = 8.0; 95 % CI = 6.6, 9.6) and AQ (MD = 5.3; 95 % CI = 4.0, 6.6). When stratified by birth-assigned sex, the prevalence of ASD did not differ among participants with gender dysphoria. No association was found between ASD and gender incongruence among individuals with gender dysphoria. CONCLUSIONS: Our findings confirm the high co-occurrence of ASD and gender dysphoria and suggest no difference in gender incongruence between autistic and non-autistic people with gender dysphoria.