Gender identity differences in age of first mental health diagnosis: A population-based study of childhood and adolescence

Abstract Introduction Gender minority (GM; i.e., trans, non-binary, and other gender diverse) individuals have an increased risk of mental health disorders, but few studies have explored disparities using population-based samples or the age of onset of this risk. Objectives The aim of the current study was to identify the age at which the gender identity disparity in physician-assessed psychiatric diagnosis and treatment for common mental health disorders can be first identified in a population-based sample linked to national health care registries. Methods All individuals aged 16 to 25 (n = 18,793) participating in the nationwide probability-based Swedish National Public Health Survey in 2018, 2020, or 2021 were included in the analyses. This sample could be linked to mental health care treatment history data in nationally comprehensive health care registries starting at age 8 years old. Results Individuals reporting a GM identity in adulthood were seven times more likely to having been diagnosed with depression and/or anxiety and about five times more likely to having been diagnosed with a neurodevelopmental disorder during childhood or adolescence compared to individuals with a cisgender identity. GM individuals’ increased likelihood of being diagnosed with depression and/or anxiety was significantly elevated from age 13, while their neurodevelopmental disorder diagnosis risk was significantly elevated from age 10, compared to cisgender individuals. Conclusions The results from this study are the first population-based evidence to show that GM individuals are more likely to be diagnosed and treated for mental health disorders early during childhood and adolescence compared to cisgender individuals. The early emergence of this increased risk requires further inquiry into causes of these early disparities. It also suggests a potential benefit of interventions that facilitate social belonging and inclusion and reduce stressors related to societal expectations of gender.