Autism prevalence continues to rise
According to a new report from the Centers for Disease Control and Prevention, the estimated prevalence of autism among 8-year-olds in New Jersey rose in the latest reporting year, 2010, to nearly 22 children per thousand, or approximately one child in 45. That figure represents the "highest ever reported for a single site" since the CDC started closely monitoring 11 U.S. states in 2000.
Walter Zahorodny, an assistant professor of pediatrics at Rutgers New Jersey Medical School, has compiled New Jersey's numbers from the start – and seen them more than double in a decade.
Rutgers Today: There once was a theory that New Jersey's autism numbers were higher than elsewhere because the state's educators and health providers are unusually good at detecting signs that a child is on the spectrum. Was that thinking valid?
Zahorodny: This state does have some of the best resources anywhere for detecting and caring for autism, but if the higher documented prevalence were only due to better detection, sooner or later the numbers would plateau and other states would catch up. That hasn't happened. In 2002, the prevalence in New Jersey translated to one child in 94. In 2006, it was one child in 57. The latest numbers show one child in 45. We need to start acknowledging that what once was a rare disorder now affects two percent of the state's children, and unfortunately I think the numbers will continue to rise.
Rutgers Today: Should people be worried about living here?
Zahorodny: There is nothing to suggest that anything in the environment is causing higher autism prevalence. If anything, New Jersey's environmental quality has improved in the past decade. Also, children born in February are no different from kids born in September. Some conditions with environmental triggers, like allergies in the spring and flu in the winter, run in seasonal cycles. There is nothing to suggest that for autism.
I think it has much more to do with demographics – the people the state attracts. Many people here are more affluent and better educated than elsewhere, and those people tend to marry each other and have children later in life. It is considered a risk factor for autism if both the mother and father are older when the child is born.
It's also very likely that our findings apply beyond New Jersey. The same demographic profile exists in counties throughout the New York metro area, and I would expect that if those areas were monitored as closely as we have studied New Jersey, their autism prevalence would be found to be similar.
Rutgers Today: Does anything else stand out in the latest findings about autism?
Zahorodny: There are far more boys than girls on the autism spectrum, and that gap has widened. In 2000, the ratio of boys to girls was 3.4 to 1. By 2010, the ratio was 5 to 1. White children are more likely to be on the spectrum than black or Hispanic children. And the percentage of children found with autism who have average to high intelligence is rising. A decade ago, only a third of children with autism had IQ scores of 70 or above. Now nearly half do.
There's also a number that speaks well of New Jersey. In 2010, the median age when first diagnosed of children here with autism spectrum disorder was three years and four months. In two of the other states surveyed, that age approached six years. Earlier detection leads to more effective treatment, and children here are more fortunate in that regard than in most of the other states.