A number of studies have tried to find a definitive link between autism spectrum disorder (ASD) and early childhood vaccination, and each has failed. The old conspiracy theory has been properly debunked time and time again, but it seems that skeptics just won’t let it die. Of course, part of the problem are the unanswered questions that must then continue to be asked. If vaccination has nothing to do with rising ASD rates, then what gives?
Part of the reason lies in the way we collect and categorize information. The definition of ASD has changed a great deal over the last few decades, and the ability to diagnose the disorder has increased in proportion to the new information. One of the biggest reasons that people believe that cases of autism are on the rise is their confusion between actual cases and diagnosed cases.
Whereas autism is nothing new, the ability of medical professionals to better diagnose the disorder leads to “new” cases. The children had autism before; it’s just that now we know they do.
Certain demographics and populations of patients are often underrepresented because they lack proper healthcare resources. As the access these communities might enjoy starts to grow, so too do the statistics for the disorders and diseases that might affect them. A decade ago, white children were far more likely to be diagnosed by ASD than other less-represented ethnicities. The numbers have been playing catch-up for a long time, but we’re finally getting there.
Another part of the puzzle is proximity to the diagnostic centers. There aren’t enough of them in more rural areas where people are less likely to travel far distances for medical care, so one region’s diagnosed individuals can differ greatly from another’s. For example, there are more reported cases of ASD in New Jersey than Arkansas, simply because New Jersey residents are closer to help.
Beyond that, medical professionals are placed under a great deal of pressure to diagnose children with potential behavioral or developmental disorders as early as possible in order to avoid less desirable outcomes. Most children aren’t diagnosed until between age four and five, which is a “late” diagnosis of a disorder for which the signs are readily noticeable by the age of two.
The conclusion that should be drawn by the laymen? There is no real reason to worry about “increasing” rates of ASD diagnosis.