Some children diagnosed with autism in early childhood may no longer have the disorder as they grow older, according to research funded by the National Institutes of Health.
"Although the diagnosis of autism is not usually lost over time, the findings suggest that there is a very wide range of possible outcomes," said Dr. Thomas R. Insel, NIMH director, said in a press release. "For an individual child, the outcome may be knowable only with time and after some years of intervention."
Autism spectrum disorders are a group of developmental disorders that cause behavioral, social and communication problems. The Centers for Disease Control and Prevention estimate one in 88 children have an ASD.
The new study looked at 34 children between 8 and 21 who had an "optimal outcome," meaning they were diagnosed with autism earlier in life but functioned normally compared to their peers later on. These subjects were matched by age, sex, and nonverbal IQ with 44 children with high-functioning autism and an additional 34 typically developing peers.
The researchers reviewed their initial diagnoses to make sure they were accurate and enlisted a second diagnostic expert, who didn't know the child's status, to review reports where the initial diagnosis had been removed.
What they discovered was the "optimal outcome" children had milder social problems than those in the high-functioning autism group in early childhood. Verbal IQ of "optimal outcome" children were slightly higher than high-functioning autism individuals. However when it came to communication and behavioral problems, there were similarities to the high-functioning subjects.
The researchers then examined all the subjects using standard cognitive tests and parent questionnaires. The "optimal outcome" children were all in regular education classes with no special education aimed at autism. The whole group showed no signs of problems with language, face recognition, communication, and social interaction.
Researchers cannot speculate which percentage of children will outgrow their ASD, but they are hoping that through the research they gathered they can see whether the diagnosis changed because brain function normalized or the brain was able to make up for autism-related deficiencies.
"All children with ASD are capable of making progress with intensive therapy, but with our current state of knowledge most do not achieve the kind of optimal outcome that we are studying," study author Deborah Fein, a professor at the Department of Psychology at University of Connecticut, said in a press release. "Our hope is that further research will help us better understand the mechanisms of change so that each child can have the best possible life."
The study published Jan. 16 in the Journal of Child Psychology and Psychiatry.
Researchers are also looking at which therapies led to the most success. Fein told HealthDay she believed behavioral treatments were the most likely to result in an "optimal outcome." However, even for children that lose the diagnosis, she said that parents should not stop therapy "prematurely" since these children are still at risk for attention problems and anxiety.
"But I want to point out that this is the result of years of hard work," she added. "This is not anything that happens overnight. I would say that at minimum we're talking about two to three years of intensive therapy to produce this outcome, but it could also be five years. It's variable.
"This is the first solid science to address this question of possible recovery, and I think it has big implications," added Dr. Sally Ozonoff of the MIND Institute at the University of California, Davis, who was not involved in the study, to the New York Times. "I know many of us as would rather have had our tooth pulled than use the word 'recover,' it was so unscientific. Now we can use it, though I think we need to stress that it's rare."
But, other experts warned that parents shouldn't get their hopes up that their child will outgrow their diagnosis.
"This study is looking at a small sample of high functioning people with autism and we would urge people not to jump to conclusions about the nature and complexity of autism, as well its longevity," Dr. Judith Gould, director of the National Autistic Society's Lorna Wing Centre for Autism, told the BBC. "With intensive therapy and support, it's possible for a small sub-group of high functioning individuals with autism to learn coping behaviors and strategies which would 'mask' their underlying condition and change their scoring in the diagnostic tests used to determine their condition in this research."