Recently, the development of the "spectrum" of autism, specifically related disorders like Asperger syndrome and ADHD, has led to the expansion of health and educational services for millions of American children and their families.

However, a new study by the American Psychiatric Association may cause that to change.

The group of experts is working on the fifth edition of its Diagnostic and Statistical Manual of Mental Disorders, the main book used by psychologists and psychiatrists to diagnose psychological disorders in patients. One of the major changes being review by a panel is the definition of autism.

From the New York Times:

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 like Asperger 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.

One analysis suggests as many as three quarters of all Americans diagnosed with Asperger syndrome would not qualify under the new guidelines.