New Definition of Autism Will Exclude Many, Study Suggests

By BENEDICT CAREY
January 19, 2012

Proposed changes in the definition of autism would sharply reduce the skyrocketing rate at which the disorder is diagnosed and might 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 now being reassessed 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 first major revision in 17 years. The D.S.M., as the manual is known, is the standard reference for mental disorders, driving research, treatment and insurance decisions. Most experts expect that the new manual will narrow the criteria for autism; the question is how sharply.

The results of the new analysis are preliminary, but they offer the most drastic estimate of how tightening the criteria for autism could affect the rate of diagnosis. For years, many experts have privately contended that the vagueness of the current criteria for autism and related disorders like Asperger syndrome was contributing to the increase in the rate of diagnoses — which has ballooned to one child in 100, according to some estimates. the rest