Rare No More

With Research Up and Stigma Down, Autism Sheds More of Its Mystery

When my daughter Isabel's autism was diagnosed in 1994, when she was 2 1/2 , I knew little about the condition. Autism was a strange word to most people. "You mean like Dustin Hoffman in 'Rain Man'?" people would ask. "You mean she's artistic?"

Back then, autism was considered a rare disorder, occurring in only about three in every 10,000 live births.

Little more than a decade later, autism has become a "major public health concern," according to Marshalyn Yeargin-Allsopp, chief of the developmental disabilities branch of the Centers for Disease Control and Prevention. The results of a CDC survey released this month suggest that about one in every 150 children in the United States has some form of autism.

Those numbers don't reflect an epidemic, as some reports have suggested, or even mean that the incidence of autism has necessarily increased. Instead, we are defining autism and measuring its prevalence differently than we did in the past. Isabel's story illustrates that evolution.

The years since Isabel's diagnosis show a rapid change in our awareness of the disorder. In 1993, the state of Maryland (where we live) told the U.S. Department of Education that the state's public schools had provided special education services during the 1992-93 academic year to just 28 children between the ages of 6 and 21 with autism.

By the time Isabel was diagnosed, Maryland's public schools claimed to have served 300 people in the same age group with autism in 1993-94 (still a small number, but an enormous increase over the previous year).

And by 2003 there were more than 4,084 children ages 3 to 22 who had been given the official coding for autism in the Maryland public school systems, a rate of 1 in 183 children.

Isabel was no longer alone.

Shifting Definitions

Like most of the illnesses psychiatrists treat, you cannot see autism under a microscope or discover it through a lab test. The only evidence we have is the individual's behavior. And until 1980, when the criteria we're familiar with today were first standardized in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-III), there was little agreement about what was and was not autism. Even now, there is an element of subjectivity in each diagnosis.

What's more, many psychiatric diagnoses come and go -- and hence rates of diagnoses go up and down and change rapidly. Several million Americans have been diagnosed with depression, for example. But many of them would not have received that diagnosis just 50 years ago. The increase does not mean that depression is more common today than in the past, but only that our way of defining depression has changed. Half a century ago, the term was used to describe only debilitating depressions that required long-term hospitalization.

The shift in how we view autism is also part of a set of broader shifts taking place in society. The growth of child psychiatry after World War II, the rise of advocacy organizations, greater public sensitivity to children's educational problems and changes in public policies (the establishment, for example, of autism as a special-education code after the 1991 Individuals with Disabilities Education Act, or IDEA) have together changed the way autism is diagnosed and defined.

As a society, we have also become more aware of children's behavioral and learning differences at earlier and earlier ages and more comfortable with diagnosis, medication and psychiatric labels. Under the rubric of autism we now find a multitude of emotional and cognitive problems -- problems that used to be given other diagnostic labels or were even considered within the range of the normal.