Co-occurring conditions and change in diagnosis in autism spectrum disorders.

OBJECTIVE: This study aimed to investigate descriptive characteristics and co-occurring neurodevelopmental and psychiatric conditions in young children, children, and adolescents with a current and consistent or past but not current (PBNC) diagnosis of autism spectrum disorder (ASD) and how such characteristics and conditions may engender a change in diagnosis of an ASD.
METHODS: Cross-sectional data of 1366 children with a parent-reported current or PBNC ASD diagnosis were obtained from the National Survey of Children's Health 2007 data set across 3 developmental stages: young children (aged 3-5 years), children (aged 6-11 years), and adolescents (aged 12-17 years). Multinomial logistic regression was used to examine demographic characteristics and co-occurring conditions that differentiate the groups with a current ASD from groups with a PBNC ASD.
RESULTS: Results indicated the co-occurring conditions that distinguish groups currently diagnosed with an ASD from groups with a PBNC ASD diagnosis. In young children, current moderate/severe learning disability, and current moderate/severe developmental delay; in children, past speech problem, current moderate/severe anxiety, and past hearing problem; and in adolescents, current moderate/severe speech problem, current mild seizure/epilepsy, and past hearing problem.
CONCLUSIONS: These findings suggest that the presence of co-occurring psychiatric and neurodevelopmental conditions are associated with a change in ASD diagnosis. Questions remain as to whether changes in diagnosis of an ASD are due to true etiologic differences or shifts in diagnostic determination.