Oral Presentation ESA-SRB-ANZOS 2025 in conjunction with ENSA

Mental health treatment utilisation among transgender and gender-diverse people following gender affirming hormone therapy: evidence from whole-of-population Australian administrative data (128222)

Karinna Saxby 1 , Tom Buchmueller 2 , Christopher Carpenter 3 , Clue Coman 4 , Brendan J Nolan 5 6
  1. Melbourne Institute: Applied Economic & Social Research, University of Melbourne, Melbourne, Victoria, Australia
  2. Ross School of Business, University of Michigan, Ann Arbor, Michigan, United States
  3. Department of Economics and Vanderbilt LGBTQ+ Policy Lab, Vanderbilt University, Nashville, Tennessee, United States
  4. Centre for Social Research in Health, University of New South Wales, Sydney, New South Wales, Australia
  5. Department of Diabetes and Endocrinology, Princess Alexandra Hospital, WOOLLOONGABBA, QLD, Australia
  6. Austin Health, University of Melbourne, Heidelberg, Victoria, Australia

Aims: Gender affirming hormone therapy (GAHT) is associated with improved self-reported mental health outcomes in transgender and gender-diverse (TGD) individuals, yet limited evidence examines mental healthcare utilisation changes after GAHT initiation. 

Methods: Using Australian administrative data (2012–2024), we identified TGD individuals initiating estradiol-based (e-GAHT) or testosterone-based GAHT (t-GAHT). We applied a dynamic difference-in-differences model to estimate within-individual changes in mental health services (general practitioner, psychiatrist, psychologist and other allied health professionals) and prescriptions (antidepressants, anxiolytics), using future GAHT recipients as controls. Effects were estimated relative to individuals’ utilisation 2 years before GAHT initiation, up to 5 years post-initiation, and stratified by age (15-24, ≥25 years) and baseline mental healthcare engagement (above/below mean mental health prescription use). 

Results: 21,073 individuals initiated e-GAHT and 11,418 initiated t-GAHT (median follow-up 4.5 and 3.8 years, respectively). Prior to initiation, e-GAHT recipients had lower engagement with mental healthcare. For both regimens, mental health service use rose at initiation but declined sharply thereafter. Five years post-initiation, t-GAHT and e-GAHT recipients used 2.59 (95%CI 1.87;3.31) and 0.29 (95%CI -0.03;0.60) fewer mental health services per year, respectively. Mental health prescription use among e-GAHT recipients initially rose but fell to 0.53 (95% CI 0.20; 0.86) at 5 years, while t-GAHT recipients used 1.02 (95%CI 0.31;1.72) fewer prescriptions per year at 5 years. Reductions in mental healthcare were more pronounced for individuals with higher baseline mental healthcare engagement as well as e-GAHT recipients aged ≥25 years.

Conclusion: GAHT initiation is associated with dynamic changes in mental healthcare use. While use increases around the time of initiation – particularly among younger e-GAHT recipients and those with limited prior mental healthcare engagement – use declines substantially over time. Altogether, GAHT may help address unmet mental health needs and contribute to longer-term reductions in mental healthcare use and associated costs among TGD individuals.