More children were diagnosed at earlier ages—a growing number of them by 3 years of age. Still, most children were not
diagnosed until after they were 4 years of age. On average, diagnosis was a bit earlier for children with autistic disorder (4
years) than for children with the more broadly defined autism spectrum diagnoses or pervasive developmental disorder not
otherwise specified (4 years, 5 months), and diagnosis was much later for children with Asperger disorder (6 years, 3
months).