And since the latest buzz suggests that early intervention is critical for successful treatment, parents of ever younger children are searching for signs. Would your pediatrician recognize them? Would you? The hype is worrisome, but the truth behind it should ease some concerns. The facts:

What is autism?

Autism was first described and named in 1943 and was said to comprise three common characteristics:

* Autistic children prefer to relate to objects over people.

* They're obsessed with maintaining routines and sameness in their lives.

* They tend to seek complete aloneness, shutting out the world around them.

While the disorder has always been said to represent a "spectrum," or range, of problems, today more children than in the past whose symptoms show both more  -- and less  -- severity are included. For instance, kids with Asperger syndrome, which refers to high intelligence without language deficits but with social impairments, are placed on the spectrum, as are those whose symptoms are so severe that a generation ago they often would have been termed mentally retarded.

No one disputes that the number of children diagnosed with an autistic spectrum disorder (ASD) has gone way up compared with statistics from 30 years ago. But as widespread as ASD appears to be  -- affecting as many as 1 in every 150 children, according to the Centers for Disease Control and Prevention  -- experts agree that it cannot be called an "epidemic."

The fact is, it's impossible to compare how common autism is today with 10 or 20 years ago. Not only are doctors better at spotting ASD, so the diagnosis is more frequent, but many experts say that doctors' interpretation of the spectrum has become so inclusive that a diagnosis of autism is no diagnosis at all. "The use of the term has expanded to the point where children referred to me as autistic lack the social deficit, which is the core symptom," says Susan Swedo, M.D., a pediatrician and the principal investigator in the National Institute of Mental Health's Intramural Research Program on autism. "We're muddying the waters."

There is a lot of over-diagnosing, agrees Joe Piven, M.D., a psychiatrist at the University of North Carolina in Chapel Hill, who directs the UNC Neurodevelopmental Disorders Research Center. Many children don't necessarily have autism, but they have "almost-autism," he says  -- symptoms that interfere with their ability to function. And although a few repetitive behaviors or social oddities don't make a child autistic, they may get him a diagnosis.

Not everyone concurs. "In many areas of the country, there is still a problem with under-diagnosis," says Nancy Minshew, M.D., a professor of psychiatry and neurology at the University of Pittsburgh's School of Medicine. There is also growing concern that minority children are diagnosed at a rate far below that of Caucasian kids, and at later ages.

Experts do agree, however, that there is no one thing called autism, but that there are autisms  -- the broad categories of "regressive" (in which a child developing normally starts to regress into autism) and "non-regressive" types (with problems apparent from infancy), as well as subtypes within these categories. To help clear up the controversy, the National Institute of Mental Health launched a vast study last September to identify variants and refine the way doctors make diagnoses. So as prevalent as autism is today, in a few years we may see ASD diagnoses spike even higher.

Melinda Marshall is a frequent contributor to Parenting.

Stumble Upon Facebook Del.icio.us Google Yahoo Digg it