Over the last decade, there has been a sharp increase in young people seeking medical treatment for gender dysphoria/gender incongruence (GD/GI). The aims of this study were to calculate yearly population-adjusted numbers of children and adolescents referred to the Norwegian National Center for Gender Incongruence (NCGI) at Oslo University Hospital (OUS) from 2000 to 2022
to describe the demographic characteristics and prevalence of psychiatric diagnoses, self-harm and suicide attempts among the referred from 2000 to 2020
and to investigate time trends. The study used data from the Gender Incongruence Registry for Children and Adolescents (GIRCA) in Norway. All persons under 18 years (n = 1258) referred to the NCGI between 2000 and 2020 were included: 68.4% assigned female gender at birth (AFAB) and 31.6% assigned male gender at birth (AMAB). We found a sharp increase in referrals to the NCGI favouring AFAB over AMAB. Nearly two in three (64.5%) had one or more registered psychiatric diagnoses. Self-harm was registered among 35.5%, and 12.7% had attempted suicide. Registered psychiatric diagnoses were significantly (p ≤ 0.001) more prevalent among AFAB (67.8%) than AMAB (57.4%). The number of registered diagnoses per person decreased significantly over time, with an average reduction of 0.02 diagnoses per person per year. Although there was a downward time trend in registered diagnoses per person, the total mental health burden among children and adolescents with GI emphasizes the need for a holistic approach.