Aug. 1, 2005 -- Home videos of children's birthday parties may validate what many parents of autistic children have suspected in retrospect: Children who seemed normal in their first year of life may regress and develop symptoms of autism by their second birthday.
A new study analyzed home videos of first- and second-year birthday parties and showed that some autistic children began displaying symptoms of the disorder by their first birthday, such as less frequent use of words or babbling.
Meanwhile, other autistic children who behaved normally at age 1 appeared to regress and showed typical symptoms of autism by age 2.
Researchers say it's the first objective evidence of autistic regression, a form of autism that accounts for about 25% of all autism cases in the U.S.
"Once again, this study provides an important lesson that parents are good reporters on what is happening with their children," says researcher Geraldine Dawson, PhD, director of the University of Washington's Autism Center, in a news release. "And it certainly suggests that in early screening for autism that we need to screen at 18, 24, and 36 months to find children who develop normally at first, but then experience a regression."
The study did not look at the cause of the autistic regression, nor any possible links to childhood vaccines. The timing of childhood vaccinations and the emergence of autism symptoms in early childhood has prompted some to suggest that the two may be related, but scientific research has largely rejected this theory.
Home Videos Document Autistic Regression
In the study, researchers analyzed first and second birthday party home videos provided by the parents of 36 young children with autism and 20 normally developing children. Of the autistic children, 15 were diagnosed with autism after the parents reported a worsening of social and/or communication skills during the second year of life. The parents of 21 of the children with autism reported that they had impairments before age 1, known as early-onset autism.
Researchers noted the frequency and duration of several behaviors seen in the videotapes, such as language, looking at other people, repetitive behavior, emotion, and playing with toys. They were unaware of the diagnosis that the children had.
They also interviewed the caregiver about the child's early development.
Their results appear in the August issue of the Archives of General Psychiatry.
By the children's second birthday, both groups of autistic children vocalized and used words less frequently, pointed less often, looked at people less often, and didn't respond when their name was called more often than the normally developing children.
Children whose parents reported autistic regression used more complex babble and words at their first birthday than normal children, while children with early-onset autism used the fewest words and least amount of babble.
In addition, children with the early-onset form of autism pointed less at their first birthday and showed more communication impediments than the other two groups at this age.
Researchers say the results of this study show that at least some children don't develop the typical symptoms of autism by the end of their first year of life, and these symptoms may emerge in the following year.
They say that by ages 3 and 4, there were no differences in the severity of autism between the two groups of autistic children in this study. But more research is needed on whether autistic regression is different than other forms of the autism.