Johnny L. Matson, PhD

Autism spectrum disorders (ASDs) are a group of 5 neuro developmental conditions (autism, Asperger syndrome, pervasive developmental disorder not otherwise specified [PDD-NOS], Rett syndrome, and disintegrative childhood disorder).1 Once thought to be rare, the incidence of these disorders is now estimated to be 1 in 150 children in the general population.2 Furthermore, the number of recognized cases has increased markedly in recent years.