Experts estimate that 1 percent of the population of children in the U.S. ages 3-17 have an autism spectrum disorder. Autism occurs in all racial, ethnic, and socioeconomic groups, and is more likely to occur in boys. It is the fastest growing developmental disability in children and there is great concern that a new definition of autism may have a huge impact on the care and treatment of people who have the disorder.
The definition is currently being assessed 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.
With school budgets stretched to the max, and cutbacks in special education, a new definition could cause more battles in determining who qualifies and who doesn't for these classes.
Tens of thousands of people receive state-backed services to help offset the disorders' disabling effects, which include sometimes severe learning and social problems, and the diagnosis is in many ways central to their lives. Close networks of parents have bonded over common experiences with children; and the children, too, may grow to find a sense of their own identity in their struggle with the disorder.
The proposed changes would probably exclude children and teens that are higher functioning. Many parents are concerned that their child would no longer qualify for services.
At least a million children and adults have a diagnosis of autism or a related disorder, like Asperger syndrome or "pervasive developmental disorder, not otherwise specified," also known as P.D.D.-N.O.S. People with Asperger's or P.D.D.-N.O.S. endure some of the same social struggles as those with autism but do not meet the definition for the full-blown version. The proposed change would consolidate all three diagnoses under one category, autism spectrum disorder, eliminating Asperger syndrome and P.D.D.-N.O.S. from the manual.
Under the current criteria, a person can qualify for the diagnosis by exhibiting 6 or more of 12 behaviors; under the proposed definition, the person would have to exhibit 3 deficits in social interaction and communication and at least 2 repetitive behaviors, a much narrower menu.
The likelihood of being left out under the new definition depended on the original diagnosis: about a quarter of those identified with classic autism in 1993 would not be so identified under the proposed criteria; about three-quarters of those with Asperger syndrome would not qualify; and 85 percent of those with P.D.D.-N.O.S. would not.
Disagreement about the effect of the new definition will almost certainly increase scrutiny of the finer points of the psychiatric association's changes to the manual. The revisions are about 90 percent complete and will be final by December.
Parents, schools, and state-governments will be keeping a close eye on any changes that the panel makes. The question comes down to where to draw the line between unusual and abnormal developmental behavior. Its decision could have an enormous impact on families already struggling to care for their autistic child.