Autism Spectrum Disorder Among Gender-Diverse Children and Adolescents: A National Cohort Study

Autism spectrum disorder (ASD) is more prevalent in transgender and gender-diverse (TGD) individuals than in the general population, yet the specific developmental pathways within and clinical outcomes of this intersection are insufficiently understood. This study examined how ASD and sex assigned at birth (SAAB) are associated with gender-related milestones, access to gender-affirming consultation and care (GACC), and psychiatric outcomes. We reviewed electronic medical records for 786 TGD children and adolescents (aged 4-19 years) presenting to a national referral clinic between 2013 and 2025. Demographic, developmental, and psychiatric variables were analyzed across four ASD-by-SAAB groups using generalized linear models and logistic regressions, with Bonferroni-adjusted post hoc comparisons (α = 0.0083). ASD was documented in 9.7% of the cohort, with referrals of autistic TGD patients increasing significantly over time. Autistic patients presented with a distinct profile, characterized by higher socioeconomic position (SEP), intellectual giftedness, non-binary gender identity, and an earlier stage of pubertal development at presentation. Crucially, while ages at gender-related milestones were largely comparable between neurotypes, autistic assigned female at birth (AFAB) adolescents were significantly less likely to initiate puberty suppression or gender-affirming hormones than their non-autistic peers. Furthermore, higher SEP was associated with earlier clinical presentation only for non-autistic youth. Autistic TGD patients exhibited a higher psychiatric burden, with an ASD diagnosis uniquely associated with elevated rates of anxiety, ADHD, and psychotropic medication use. These findings reveal a disparity between developmental synchrony and clinical access, underscoring the need for autism-informed protocols to support equitable gender-affirming care.