Abstract
OBJECTIVE: This study evaluated the potential impact of proposed DSM-5 diagnostic criteria for autism spectrum disorder (ASD). METHOD: The study focused on a sample of 933 participants evaluated during the DSM-IV field trial; 657 carried a clinical diagnosis of an ASD, and 276 were diagnosed with a non-autistic disorder. Sensitivity and specificity for proposed DSM-5 diagnostic criteria were evaluated using field trial symptom checklists as follows: individual field trial checklist items (e.g., nonverbal communication); checklist items grouped together as described by a single DSM-5 symptom (e.g., nonverbal and verbal communication); individual DSM-5 criterion (e.g., social-communicative impairment); and overall diagnostic criteria. RESULTS: When applying proposed DSM-5 diagnostic criteria for ASD, 60.6% (95% confidence interval: 57%-64%) of cases with a clinical diagnosis of an ASD met revised DSM-5 diagnostic criteria for ASD. Overall specificity was high, with 94.9% (95% confidence interval: 92%-97%) of individuals accurately excluded from the spectrum. Sensitivity varied by diagnostic subgroup (autistic disorder = 0.76; Asperger's disorder = 0.25; pervasive developmental disorder-not otherwise specified = 0.28) and cognitive ability (IQ < 70 = 0.70; IQ ≥ 70 = 0.46). CONCLUSIONS: Proposed DSM-5 criteria could substantially alter the composition of the autism spectrum. Revised criteria improve specificity but exclude a substantial portion of cognitively able individuals and those with ASDs other than autistic disorder. A more stringent diagnostic rubric holds significant public health ramifications regarding service eligibility and compatibility of historical and future research.