ST LOUIS: People with autism are more intelligent and able to function better than previously believed, but mistrust of doctors, biased tests and the Internet have bred myths about the condition, experts said on Sunday.
At a meeting of the American Association for the Advancement of Science, researchers presented reports showing that even autistic people who do not speak can have above-average intelligence.
They also offered additional studies disputing claims that vaccines can cause autism.
"The current figures are that 75 per cent of autistic people are mentally retarded, with the mute the most ... impaired," said Dr Laurent Mottron, an autism researcher at Montreal's Hopital Riviere des Prairies.
But Mottron believes the wrong intelligence tests are used to assess autistic children. Many are tested using the Wechsler scale, a common IQ test that includes questions about words and concepts learned in school.
The Raven's Progressive Matrices test measures abstract reasoning and consistently gives autistic children higher scores, Mottron said.
The average boost in score is 30 points, Mottron said, enough to put someone previously considered mentally retarded into the normal range and the average to gifted status.
Mottron was so impressed by the abilities of one autistic student, Michelle Dawson, that he made her a co-author of some of his papers.
Autism is a term used to describe a broad range of symptoms, from an inability to use language normally, to exhibiting deeply disturbed and repetitive behaviours. The US Centres for Disease Control and Prevention says it affects anywhere between one in 500 and one in 166 children.
Morton Gernsbacher at the University of Wisconsin-Madison questioned a common idea among autism researchers that autistic people lack a "theory of mind," which, among other things, gives an ability to empathize with others.
Again, she said, the wrong tests are used to assess this ability.
Dr Judith Grether, a California epidemiologist, said she questions the idea that there is a new autism epidemic. She said it is impossible to find out how many cases of autism there were in the past, because many people with autism were often diagnosed as retarded, or never diagnosed.
Without that information, it is impossible to say if the number of cases has grown, she said.
"We have to do the studies to find the answers," she said.
Grether said researchers in California have begun taking prenatal blood samples from pregnant women and will look for clues when and if some of their children are diagnosed with autism. They are examining hormones, heavy metals, immune system proteins and other factors.
The studies found no link with vaccines, said Dr Irving Gottesman, a psychiatrist at the University of Minnesota, but said the CDC has initiated four new studies "to tie up the loose ends."
New studies are focusing on genetic susceptibilities.
Gottesman said the studies may help ease the fears of parents that a vaccine-autism link has been covered up.
But he said scientists are battling a plethora of Internet websites devoted to the idea that mercury causes autism such as http://www.safeminds.org/.
Gernsbacher, the mother of a child with autism, said some parents may join these lobbying groups over the advice of doctors because they get "pat answers" to initial concerns about their children.
"The mistrust (of government-funded studies and of their paediatricians) may have arisen from those kind of experiences," she said.
Source: China Daily