ABSTRACT
BACKGROUND: The cognitive functioning of children who received a diagnosis of autistic spectrum disorder (ASD) during the preschool years was assessed at the time of diagnosis (Time 1) and reassessed, on average, 3 years and 5 months later (Time 2). METHOD: A total of 50 children were assessed (76% male, n = 38); the group had an average age of 4 years 3 months at Time 1 and 7 years 8 months at Time 2. RESULTS: There was a significant positive relationship (r = 0.791, p < 0.01) between the group's Full Scale Intelligence Quotient (FSIQ)/Developmental Quotient (DQ) at Time 1 and at Time 2. Results indicated a significant increase in FSIQ/DQ over time for the total group and for both the High Functioning (IQ ⩾ 70) and Low Functioning (IQ < 70) groups. Of the total samples, 32% showed a clinically significant change in FSIQ/DQ of 15 points or more from Time 1 to Time 2. When age at Time 1 was included as a covariate, no significant difference was identified for change in FSIQ over time. The practical implications of the findings are discussed.
