Correlation between Severity and Cognitive Functioning in Autism Spectrum Disorder

Background: Previous research has shown that the severity of autism spectrum disorder (ASD) is associated with general intelligence (Coplan, 2003). Intellectual functioning and ASD severity varies on a case-by-case basis.

Objectives: The current study investigated the relationship between General Conceptual Ability (GCA) on the Differential Ability Scale, Second Edition (DAS-II) and severity of ASD. It was expected that GCA and ASD severity would be associated.

Methods: Participants included 160 children diagnosed with ASD (Males n= 123, females n= 37) and data was collected over a two-year period from a community-based developmental assessment clinic in South Florida. Ages of the participants ranged from two to nineteen years. Participants were assessed using the DAS-II and the Autism Diagnostic Observation Schedule, Second Edition (ADOS-II).

Results: As hypothesized, there was a significant negative correlation (r=-.334, p<.01) found between the two variables.

Conclusions: These results suggest that as ASD severity increases, general conceptual ability decreases. These findings provide useful information to inform prognosis and intervention strategies (Coplan, 2003). These findings may also help to inform appropriate treatment plans based on severity of ASD symptoms and cognitive functioning.