Is There Really An Autism Epidemic?
Nowadays many hear of the so called “autism epidemic”, and various popular authors such as Gary Null, have claimed that the apparently rapid increase in autism, is due to vaccines or to “environmental toxins” or to some other aspect of modern life. But is this really the case?
It is an undeniable fact that the number of people diagnosed with autism has significantly increased over the years. From 1976 to 1991 population surveys reported rates of 4.4 cases among 10 000 people, and from 1991 to 2001 the rate increased to 12.7 (Almost three times), which suggests that now 1 person every 1000 has an autistic spectrum disorder.
This rapid increase is the main fact why the term “autism epidemic” was formed. Many people have attributed this rapid expansion to things like environmental toxins or poisoning by Mercury. All of those explanations have been subsequently refuted by serious research. In order to understand why they were refuted, we first have to know what actually causes autism.
The scientific evidence available today seems to indicate that autism is an organic disorder which is caused by a disruption to the developing central nervous system during development. The most likely explanation is that autism results from a wide range of causes interacting with one another.
Evidence that autism is a biological condition can be found in Twin studies. The probability that monozygotic (identical) twins both will suffer from an autism spectrum disorder is remarkably high- higher than, for example, Schizophrenia. This suggests that there is a strong genetic component which predisposes people to develop an autism spectrum disorder. Although, it is necessary to note that not all monozygotic twins of an individual with autism will have an autism spectrum disorder.
One study conducted by Firth (1989), on eleven children with autism who had an identical twin, found that only four (36%) had an identical twin that also had an autism spectrum disorder, but still even a correlation of 0.34 strongly indicates a genetic influence.
It is more likely that the increase is caused by a change in diagnostic practices. Nowadays autism is no longer understood as a black or white label, but it is better understood as a wide range of disorders which among others incorporates Aspergers syndrome.
So in conclusion. The answer to ‘Is there an autism epidemic?’. Is a straightforward no. The only thing that happened was an increase in the scope of diagnostic criteria. There is no virus, no poisonous vaccine or anything really that is responsible for the rise in the number of cases diagnosed with autism. It’s just that nowadays instead of a diagnosis of autism people are diagnosed with an autism spectrum disorder which has a much wider criteria of diagnosis.