Comparison of developmental/intellectual changes between autistic disorder and pervasive developmental disorder not otherwise specified in preschool years

This study is the first to compare the change in developmental quotient (DQ) or IQ between autistic disorder (AD) and pervasive developmental disorder not otherwise specified (PDDNOS) in preschool years. Forty-nine AD children and 77 PDDNOS children were evaluated at age 2 and at age > or =5. The AD children were significantly lower in DQ/IQ at initial evaluation and outcome evaluation (also with initial DQ being controlled for) than the PDDNOS children.