In one large-scale study the rate of psychiatric comorbidity increases from 10% to 61% among males and from 22% to 55% among females.

In a nationwide Finnish study of all under-23-year-old individuals referred to a gender clinic between 1996 and 2019, comprising 2,083 gender-referred youth, psychiatric needs increased sharply among those who underwent medical transition. The rate of psychiatric comorbidity increased from 9.8% to 60.7% among the males who sought medical transition and from 21.6% to 54.5% among the females who sought medical transition, while rates in the control group remained stable. After adjustment, gender-referred adolescents were three to six times more likely to require psychiatric care than controls.

Ruuska, S.-M., Tuisku, K., Holttinen, T., and Kaltiala, R. (2026). “Psychiatric Morbidity Among Adolescents and Young Adults Who Contacted Specialised Gender Identity Services in Finland in 1996–2019: A Register Study,” Acta Paediatrica: 1–9. https://doi.org/10.1111/apa.70533.