High-Resolution Mapping of Healthcare Pathways in Autism

Autistic children and adolescents experience substantial psychiatric and somatic comorbidity, but whether this excess morbidity follows structured diagnostic patterns or temporal trajectories remains unclear. We conducted a nationwide register-based study of 101,521 autistic individuals in Sweden and 958,093 age- and sex-matched peers, followed from birth through early life until a median age of 19.8 years. Across 12.86 million diagnostic codes from 9.49 million inpatient and specialist outpatient healthcare encounters, autistic individuals had increased risk of 165 of 187 examined conditions. Excess morbidity was not diffusely distributed across the phenome, but clustered into seven distinct, system-dominant domains. Temporal trajectory analyses further showed that autism-enriched diagnostic sequences were concentrated within respiratory, congenital, and mental-injury/poisoning-related domains. These findings indicate that morbidity in autistic young people is both clinically structured and temporally organized, providing a population-level framework for understanding the concentrated domains that drive excess healthcare burden.