When ADHD Behaviors Occur in Young Children, Consider Autism Spectrum Disorder

Martin T. Stein, MD reviewing Miodovnik A et al. Pediatrics 2015 Sep 14.

Behaviors consistent with attention-deficit/hyperactivity disorder in young children may mask a diagnosis of autism.

Diagnosing autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in young children is often challenging in primary care pediatrics. Typical ASD behaviors are variable and may not be observed in brief primary care visits (NEJM JW Pediatr Adolesc Med Mar 2015 and Pediatrics 2015 Jan 12 [e-pub]). Although pediatricians have considerable experience with ADHD in school-age children, ADHD behaviors in preschool-age children may be difficult to differentiate from normal behaviors. Also, some phenotypic features of ADHD and ASD overlap.

In a national random-digit–dialed sample survey of households with children aged 2 to 17 years (>85,000 families), 1496 parents reported that their child had a diagnosis of ASD, about 20% of whom had been initially diagnosed with ADHD. Among children who received a diagnosis of ADHD before ASD, the ASD diagnosis occurred about 3 years later than in children in whom ADHD was diagnosed simultaneously with or after ASD. When ADHD was the initial diagnosis, the likelihood of ASD diagnosis occurring after age 6 years was elevated 30-fold.

Citation(s):

Miodovnik A et al. Timing of the diagnosis of attention-deficit/hyperactivity disorder and autism spectrum disorder. Pediatrics 2015 Sep 14; [e-pub].