Researchers studying home videotapes of children’s first and second birthday parties have confirmed what a number of parents have been claiming for years — that some youngsters who are seemingly normal at age 1 regress and exhibit the characteristic behaviors of autism by the end of their second year.
In a study published this week in the Archives of General Psychiatry, research done at the UW’s Autism Center provides the first objective evidence for autistic regression. This form of autism is estimated to account for about 25 percent of all autism cases in the United States.
The study did not address the cause of autistic regression or the possible role that childhood vaccines might play in children developing autism, according to lead author Geraldine Dawson, director of the UW’s Autism Center.
“Once again, this study provides an important lesson that parents are good reporters on what is happening with their children. It underscores the importance of professionals to listen to parents,” said Dawson. “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 researchers examined the birthday videos of 56 children — 15 who were later diagnosed with autism and whose parents reported that their children experienced regression in the first three years of life; 21 whose parents reported that their child had symptoms early in life and had no regression; and 20 typically developing youngsters. The children’s behavior was coded by trained observers who were not aware of which children had been diagnosed with autism or regression. Parents also filled out a detailed questionnaire about their child’s development during the first two years of life.
Perhaps the study’s most striking finding involved verbal communication. The three groups differed significantly in their use of complex babbling and use of words at 12 months of age. Children later diagnosed with regressive autism used complex babbling and words much more frequently than those diagnosed with early onset autism. Typically developing youngsters fell between the groups of children with autism. However, a year later typically developing infants showed a dramatic increase in the use of words and complex babbling while the two groups of toddlers with autism either lost their language or failed to make meaningful gains.
Children with regressive autism at age 2 displayed other symptoms of autism that didn’t show up at 1, such as not pointing or using their body to refer to objects, not turning when their name was called and not looking at other people. Both groups of children with autism significantly decreased their amount of looking at other people in the second year of life.
Dawson said these findings corroborate parent reports that some children with autism use words spontaneously and meaningfully, use gestures and participate in social games early on and then lose these skills.
The parental questionnaires also indicated that children with regressive autism had regulatory difficulties such as sleeping problems and being soothed when upset prior to the onset of autism symptoms.
“This does suggest that there might be an early vulnerability in the development of the nervous system and that these children weren’t developing normally,” she said.
The researchers also found there were no differences at ages 3 and 4 in the severity of autism, IQ, adaptive behavior or neuropsychological functioning between children with a history of regression versus those with early onset autism
The UW Autism Center continues to track the children with autism in the study to see if there are differences in the course of regressive autism from early onset autism and to determine if regression is a distinct form of the developmental disorder.
The research was funded by the National Institute of Child Health and Human Development. Co-author of the study is Emily Werner, a research scientist at the Pennsylvania State University who conducted the research while working on her doctorate in psychology at the UW.