Is autism increasing?

There are many controversies over autism...is the prevalence increasing or the number of diagnoses; is it caused by vaccines, toxins in environment, age of father? Certainly, we are attempting to diagnose earlier (and more often) because we believe the sooner treatment can begin, the better the outcome. We also see a high percentage of children who have been previously diagnosed, but no longer have the disorder. That begs the question, "How good is the diagnosis?" Stanford neurobiologist and researcher Ricardo Dolmetsch talks about his own child and the research he and others are doing in this recorded interview.

Vaccines were initially suspected of causing autism. The world scientific community, however, has ruled out a relationship between thimerosol, the mercury-containing preservative used in many vaccines, and autism. We know that most children get vaccinated, but the incidence of autism is not uniform throughout our population. Researchers find clusters of incidence in certain geographic areas, leading us to believe that those families may simply have access to resources that will diagnose the disorder.

Dr. Dolmetsch talks about research in identical twins (where the chance of both having autism if one has it is 90%) vs. fraternal twins (where the chance is only 5% of both having autism if one has). Based on that research, scientists believe there is a strong genetic basis, not due to just one gene (because you share more than one gene with your sibling), but due to many genes. With each successive generation, humans have approximately 150 new gene mutations, and just one of those mutations could mean the difference between having autism or not.

Paternal age also seems to be a cause, because as men age, their sperm accumulate more of these genetic mutations. More affluent people are marrying later and having children later (mothers average age now is 29, fathers 38), 10-15 years later than 1 or 2 generations ago. Both paternal age and geography suggest you are more likely to get autism if you come from a high socio-economic family and live in a nice neighborhood.

Recent research has included re-programming skin cells from children with autism into stem cells. Those cells are used to make neurons (in a dish) that enable scientists to study the electrical signals and connections in the brain cells of those children. Fortunately, the influx of money and attention to autism research in the last few years is helping us move in the right direction of finding a cure.

If you know someone with a child who has autism, please point them to this page which suggests specific toys for use with autism.