ATLANTA — A few decades ago, people probably would have said kids like Ryan Massey and Eddie Scheuplein were just odd. Or difficult.
Both boys are bright. But Ryan, 11, is hyper and prone to angry outbursts, sometimes trying to strangle a classmate who annoys him. Eddie, 7, has a strange habit of sticking his shirt in his mouth and sucking on it.
Both were diagnosed with a form of autism. And it's partly because of cases like theirs that autism appears to be skyrocketing: In the latest estimate, as many as 1 in 150 children have some form of this disorder. Groups advocating more research money call autism "the fastest-growing developmental disability in the United States."
Indeed, doctors are concerned there are even more cases out there, unrecognized: The American Academy of Pediatrics last month stressed the importance of screening every child -- twice -- for autism by age 2.
But many experts believe these unsociable behaviors were just about as common 30 or 40 years ago. The recent explosion of cases appears to be mostly caused by a surge in special education services for autistic children, and by a corresponding shift in what doctors call autism.
Autism has always been diagnosed by making judgments about a child's behavior; there are no blood or biological tests. For decades, the diagnosis was given only to kids with severe language and social impairments and unusual, repetitious behaviors.
Many children with severe autism hit themselves or others, don't speak and don't make eye contact.
Blake Dees, a 19-year-old from Suwanee, Ga., falls into that group. For the last eight years, he has been in a day program with intense services, but he still doesn't talk, he's not toilet-trained, and he has a history of trying to eat anything -- even broken glass.
But he's not a typical case.
In the 1990s, the autism umbrella expanded, and autism is now shorthand for a group of milder, related conditions, known as "autism spectrum disorders."
The spectrum includes Asperger's syndrome and something called PDD-NOS (for pervasive developmental disorder not otherwise specified). Some support groups report that more than half of their families fall into these categories, but there is no commonly accepted scientific breakdown.
Gradually, there have been changes in parents' own perception of autism, the autism services schools provide, and the care that insurers pay for, experts say.
Eddie, of Buford, Ga., was initially diagnosed with obsessive-compulsive disorder, attention deficit hyperactivity disorder and other conditions. But the services he got in school were not very helpful.
His mother, Michelle, said a diagnosis of autism brought occupational therapy and other, better services.
"I do have to admit I almost like the idea of having the autistic label, at least over the other labels, because there's more help out there for you," she said.
"The truth is there's a powerful incentive for physicians and schools to classify children in a way that gets services," said Dr. Edwin Trevathan of the U.S. Centers for Disease Control and Prevention.
Many with Asperger's and PDD-NOS succeed in school and do not -- at first glance -- have much in common with people like Dees.
At a recent gathering of families with Asperger's children in the Atlanta area, parents told almost comical stories about kids who frequently pick their noses, douse food in ketchup or wear the same shirt day after day.
Such a frank, humorous exchange was once a rarity. Doctors for many years believed in the "refrigerator mom" theory, which held that autism was the result of being raised by a cold, unloving mother. The theory was discredited, but it was difficult to dislodge from the popular conscience.
Even in the early 1980s, some parents were more comfortable with a diagnosis of mental retardation than autism, said Trevathan, director of the CDC's National Center on Birth Defects and Developmental Disabilities.
Today, parents are more likely to cringe at a diagnosis of mental retardation, which is sometimes equated to a feeble-mindedness and may obscure a child's potential.
And increasingly, professionals frown at the term: The special education journal Mental Retardation this year changed its name to Intellectual & Developmental Disabilities.
The editor said that "mentally retarded" is becoming passe and demeaning, much like the terms "idiot," "imbecile" and "moron" -- once used by doctors to describe varying degrees of mental retardation.
In contrast, autism has become culturally acceptable -- and a ticket to a larger range of school services and accommodations. In 1990, Congress added the word "autism" as a separate disability category to a federal law that guarantees special education services, and Education Department regulations have included a separate definition of autism since 1992.
Before that, children with autism were counted under other disabling conditions, such as mental retardation, said Education Department spokesman Jim Bradshaw.