Proposed changes to the official diagnosis of autism will not reduce the proportion of children found to have it as steeply as many have feared, scientists reported on Tuesday, in an analysis that contradicts several previous studies.
Earlier research had estimated that 45 percent or more of children currently on the “autism spectrum” would not qualify under a new definition now being refined by psychiatric researchers — a finding that generated widespread anxiety among parents who rely on state-financed services for their children. The new report, posted online Tuesday by The American Journal of Psychiatry
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“What I would say to families worried about the new criteria is that they’re more open-ended than the old ones,” said Catherine Lord, the senior researcher on the study. “So it’s very important to find a clinician who understands them, and who is not rushed when making a diagnosis.”
The new analysis, the largest to date, is effectively an answer to previous studies that had forecast many more children would not meet the new definition. Dr. Lord serves on the panel that proposed the new definition.
“Everyone has been waiting to see what the impact of the new diagnosis is going to be, and this study is the most comprehensive we have to date,” said Sally Ozonoff, vice chairwoman for research in the department of psychiatry and behavioral sciences at the University of California, Davis, MIND Institute. Dr. Ozonoff was not involved in the research or the debate over its implications.The article: Marisela Huerta, Ph.D.; Somer L. Bishop, Ph.D.; Amie Duncan, Ph.D.; Vanessa Hus, M.Sc.; Catherine Lord, Ph.D., "Application of DSM-5 Criteria for Autism Spectrum Disorder to Three Samples of Children With DSM-IV Diagnoses of Pervasive Developmental Disorders," The American Journal of Psychiatry, VOL. 169, No. 10 Full text currently available here.
The abstract:
Objective Substantial revisions to the DSM-IV criteria for autism spectrum disorders (ASDs) have been proposed in efforts to increase diagnostic sensitivity and specificity. This study evaluated the proposed DSM-5 criteria for the single diagnostic category of autism spectrum disorder in children with DSM-IV diagnoses of pervasive developmental disorders (PDDs) and non-PDD diagnoses.
Method Three data sets included 4,453 children with DSM-IV clinical PDD diagnoses and 690 with non-PDD diagnoses (e.g., language disorder). Items from a parent report measure of ASD symptoms (Autism Diagnostic Interview–Revised) and clinical observation instrument (Autism Diagnostic Observation Schedule) were matched to DSM-5 criteria and used to evaluate the sensitivity and specificity of the proposed DSM-5 criteria and current DSM-IV criteria when compared with clinical diagnoses.
Results Based on just parent data, the proposed DSM-5 criteria identified 91% of children with clinical DSM-IV PDD diagnoses. Sensitivity remained high in specific subgroups, including girls and children under 4. The specificity of DSM-5 ASD was 0.53 overall, while the specificity of DSM-IV ranged from 0.24, for clinically diagnosed PDD not otherwise specified (PDD-NOS), to 0.53, for autistic disorder. When data were required from both parent and clinical observation, the specificity of the DSM-5 criteria increased to 0.63.
Conclusions These results suggest that most children with DSM-IV PDD diagnoses would remain eligible for an ASD diagnosis under the proposed DSM-5 criteria. Compared with the DSM-IV criteria for Asperger’s disorder and PDD-NOS, the DSM-5 ASD criteria have greater specificity, particularly when abnormalities are evident from both parents and clinical observation.
