Most children with autism have ADHD, and children with ADHD-Combined and children with autism have high rates of irritable, oppositional, and aggressive behavior. Despite similar symptoms, prescribing practices may differ between autism and ADHD, which has not been examined in a single study. 1407 children with autism and 1036 with ADHD without autism, 2-17 years, were compared with 186 typical peers. Symptom scores were maternal Pediatric Behavior Scale ratings in eight areas (ADHD, oppositional/aggressive, irritable/angry, anxious, depressed, and social, writing, and learning problems). Psychotropics were prescribed to 38.0% with ADHD-Combined, 33.3% with autism, and 20.2% with ADHD-Inattentive, most often an ADHD medication (22.1% stimulant, 2.3% atomoxetine), antipsychotic (7.8%), SSRI (5.5%), and alpha agonist (4.9%).
ADHD medications were more often prescribed than other medications in all diagnostic groups. Compared to autism, children with ADHD-Combined were more likely to be prescribed an ADHD medication, whereas antipsychotics and SSRIs were more likely to be prescribed in autism than in ADHD-Combined. Children with ADHD-Inattentive were least impaired and least likely to be medicated. More severely impaired children were more often medicated regardless of diagnosis. Symptom scores were far worse for treated and untreated children with ADHD and with autism than for typical peers.