The MIND Institute’s study, published May 14 in the Journal of Autism and Developmental Disorders, evaluated changes in symptom severity in early childhood and the potential factors associated with those changes. It included 125 children (89 boys and 36 girls) with ASD from the Autism Phenome Project(APP), a longitudinal project in its 14th year at the MIND Institute. The children received substantial community-based autism intervention throughout their childhood.
The researchers used a 10-point severity measure called the ADOS Calibrated Severity Score (CSS) derived from the Autism Diagnostic Observation Schedule (ADOS), the gold standard assessment tool in autism research. They computed a severity change score for participants as the difference between their ADOS CSS scores at age 6 and at age 3. A change of two points or more was considered a significant change in symptom severity.