Autistic children on followup: change of diagnosis.

The present study compared baseline assessments of 30 autistic children studied at ages 2.8 to 6.3 years (mean = 4.5; median = 4.5) with assessments at followup 0.38 to 14.3 years later (mean = 5.05; median = 4.33). The assessments included diagnosis, Severity of illness, and intellectual functioning. At the time of followup, when they participated in the American Psychiatric Association's DSM-IV Field Trial, the subjects' ages ranged from 5.5 to 19.25 years (mean = 9.60). At followup, a clinical diagnosis of autistic disorder was made in 22 of the 30 children; autistic disorder, residual state was diagnosed in 6 children, and pervasive developmental disorder not otherwise specified (PDDNOS) was diagnosed in 2 children. The group of children who, on followup, no longer met the diagnosis of autistic disorder had lower severity of illness ratings and higher intellectual functioning at baseline and at followup than those children who remained diagnosed as autistic disorder; they also showed a rise in intellectual functioning over time whereas those children who remained diagnosed as autistic did not. Both groups showed decreases in severity of illness over time.