Despite the high rates of mental disorder in adolescents and young adults, treatment utilisation is low. Using Australian longitudinal administrative and survey data, we show an increasing proportion of young people are accessing nervous system scripts as they age. Younger cohorts have increasingly accessed these scripts earlier; usage is generally higher among disadvantaged groups and in regions with better mental health service access. Less than half of all young adults facing very high psychological distress in 2018 had recently accessed mental health care. Instead of professional help, young people turn to friends and family for help with personal and emotional problems.