Hospitalizations in adolescents with autism spectrum disorder are rising in Spain

Autism spectrum disorder (ASD) is a leading mental condition among adolescents globally and is associated with premature mortality. The analysis of hospitalization rates and trends in youth with ASD could be important for guiding earlier diagnosis and prompt interventions. We retrospectively analyzed all hospitalizations in children and adolescents aged 11–18 years with ASD in Spain. The Spanish National Registry of Hospital Discharges was examined, spanning 2000 to 2021. During the 22-year study period, there were 2,015,589 hospitalizations among adolescents in Spain, of which 118,609 (5.9%) involved mental disorders. ASD was reported in 6,659 admissions, representing 5.6% of hospitalizations among youth with mental health disorders. Boys comprise 74.4%. Median age was 14 years old. Admissions with ASD experienced a 74-fold increase during the study period (p < 0.001). The in-hospital mortality rate for youth with ASD was 0.33%. Adolescents with ASD, as compared to those with other psychiatric conditions, had a higher rate of comorbid mental health disorders. However, intellectual disability was more frequent in youth with ASD than in the rest. Admissions of adolescents with ASD slightly declined during the first year of the COVID-19 pandemic but resumed their rising trend thereafter. Hospitalizations in adolescents with ASD have significantly increased in Spain during the last two decades. Boys represent nearly three-quarters of admissions.