Final DSM-5 under-identifies mild Autism Spectrum Disorder: Agreement between the DSM-5, CARS, CASD, and clinical diagnoses

Agreement between the final DSM-5 ASD criteria, Childhood Autism Rating Scale (CARS), and Checklist for Autism Spectrum Disorder (CASD) was assessed in 143 children with ASD and other disorders (e.g., ADHD, intellectual disability, and oppositional defiant disorder). Diagnostic agreement between the CARS and CASD was high (94%), but their agreement with the DSM-5 was lower (84% and 88%). Agreement between the DSM-5 and both the CARS and CASD increased to 94% and diagnostic accuracy increased from 92% to 96% when one less DSM-5 social communication and interaction symptom was required for a diagnosis. Children with ASD not meeting DSM-5 criteria most often did not have criterion A2 (deficits in nonverbal social communication). Total scores on the DSM-5, CASD, and CARS were far higher for children with mild ASD (formerly PDDNOS) than no ASD, indicating that these children are clearly on the autism spectrum and are quite different from children with other disorders. However, only one child with mild ASD was identified by the DSM-5. This study and 11 others show that the DSM-5 under-identifies children with ASD, particularly children at the mild end of the spectrum. This can be rectified by requiring one less social communication and interaction symptom for a diagnosis. (C) 2013 Elsevier Ltd. All rights reserved.