Proposed changes in the definition of autism would sharply reduce the skyrocketing rate at which the disorder is diagnosed and may make it harder for many people who would no longer meet the criteria to get health, educational and social services, a new analysis suggests.
The definition is under review by an expert panel appointed by the American Psychiatric Association, which is completing work on the fifth edition of its Diagnostic and Statistical Manual of Mental Disorders. The D.S.M, as the manual is known, is the standard reference for mental disorders, driving research, treatment and insurance decisions.
The study results, presented on Thursday at a meeting of the Icelandic Medical Association, are still preliminary, but they offer the latest and most dramatic estimate of how tightening the criteria for autism could affect the rate of diagnosis. Rates of autism and related disorders likeAsperger syndrome have taken off since the early 1980s, to prevalence rates as high as one in 100 children in some places. Many researchers suspect that these numbers are inflated because of vagueness in the current criteria.
"The proposed changes would put an end to the autism epidemic,” said Dr. Fred R. Volkmar, director of the Child Study Center at Yale University School of Medicine and an author of the new analysis. “We would nip it in the bud — think of it that way.”Experts working on the new definition — a group that formerly included Dr. Volkmar — strongly questioned the new estimate. “I don’t know how they’re getting those numbers,” said Catherine Lord, a member of the task force working on the diagnosis.