For the one in every 100 or so children in this country with autism, a diagnosis is a critical link to treatment and services. It means that school districts will provide extra resources, and insurance carriers will pay for medical and psychiatric treatment.

The word itself has been in use for more than 100 years, but as the psychiatric community prepares to update the definition of “autism,” many parents have worried that if the definition changes, their kids will lose the diagnosis and the services that go with it.

The latest evidence suggests that most families need not worry.

The definition in question is part of the upcoming fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Published by the American Psychiatric Association, it sets the standard for how health-care providers classify mental disorders. The book first listed autism as a unique diagnosis in 1980, but its definition hasn’t been revised since 1994.

One reason the update is causing such a stir is that the proposed definition collapses autism spectrum subcategories into one single diagnosis. This means that diagnoses like Autistic Disorder, Asperger’s syndrome and “Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS)” would go away, leaving only autism spectrum disorder (ASD) as a clinical label. Many parents have expressed concerns that their child’s diagnosis will disappear along with the subcategories.

Going forward, “the job of a clinical psychologist is to answer a question of, ‘Is it ASD or not,’ rather than, ‘Is it Autistic Disorder or Asperger’s disorder or PDD-NOS,’” says Marisela Huerta, Ph.D., a psychologist at Weill Cornell Medical College in New York. But, she says, parents don’t need to worry. A recent study led by Huerta suggests that most kids with a current diagnosis on the spectrum would keep it under the new guidelines.

The proposed overhaul is actually more inclusive in some ways than the current definition. The new definition would:

  • Include sensory interests and aversions among the symptoms used to define ASD – These symptoms – being especially picky about food or irritated by the texture of clothing, for instance – aren’t included in the current diagnosing criteria.
  • No longer require that a child exhibit evidence of developmental delays before age 3 – Instead, the definition would require that a child show examples of unusual behavior “in early childhood,” making it easier for clinicians to diagnose children whose delays weren’t noted early on.
  • Account for the fact that social impairments may change over time – ASD may look different at age 3 than, say, at age 10 or 30.

The autism guidelines are still under review, and won’t become official until 2013. Regardless, parents who suspect their child may have a problem should take good notes, bring those notes to their pediatrician and ask for a referral to a psychologist. And with any health provider, get another opinion if you don’t feel you’ve been heard.

Christina Elston is a senior editor and health writer for Dominion Parenting Media.