Increase in diagnoses of autism

This is an interesting article I found whilst researching autism on wikipedia. There's heaps of info out there on the web about autism, but I am very interested in the fact that diagnoses of autism has increased world-wide. My personal belief is that autism is a neurological disorder caused by genetic mutation, but I have nothing to back up this belief - since I am no scientist. :)

For more details on this topic, see Autism epidemic.

The number of reported cases of autism has increased dramatically over the past decade. Statistics in graph from the National Center for Health Statistics.

There has been an explosion worldwide in reported cases of autism over the last ten years, which is largely reminiscent of increases in the diagnosis of schizophrenia and multiple personality disorder in the twentieth century. This has brought rise to a number of different theories as to the nature of the sudden increase.

Epidemiologists argue that the rise in diagnoses in the United States is partly or entirely attributable to changes in diagnostic criteria, reclassifications, public awareness, and the incentive to receive federally mandated services. A widely cited study from the M.I.N.D. Institute in California (17 October 2002), claimed that the increase in autism is real, even after those complicating factors are accounted for (see reference in this section below).

Other researchers remain unconvinced (see references below), including Dr. Chris Johnson, a professor of pediatrics at the University of Texas Health Sciences Center at San Antonio and cochair of the American Academy of Pediatrics Autism Expert Panel, who says, "There is a chance we're seeing a true rise, but right now I don't think anybody can answer that question for sure." (Newsweek reference below).

The answer to this question has significant ramifications on the direction of research, since a real increase would focus more attention (and research funding) on the search for environmental factors, while little or no real increase would focus more attention to genetics. On the other hand, it is conceivable that certain environmental factors (vaccination, diet, societal changes) may have a particular impact on people with a specific genetic constitution. There is little public research on the effects of in vitro fertilization on the number of incidences of autism.

One of the more popular theories is that there is a connection between "geekdom" and autism. This is hinted, for instance, by a Wired Magazine article in 2001 entitled "The Geek Syndrome", which is a point argued by many in the autism rights movement^[4]. This article, many professionals assert, is just one example of the media's application of mental disease labels to what is actually variant normal behavior—they argue that shyness, lack of athletic ability or social skills, and intellectual interests, even when they seem unusual to others, are not in themselves signs of autism or Asperger's syndrome. Others assert that it is actually the medical profession which is applying mental disease labels to children who in the past would have simply been accepted as a little different or even labeled 'gifted'. See clinomorphism for further discussion of this issue.

Due to the recent publicity surrounding autism and autistic spectrum disorders, an increasing number of adults are choosing to seek diagnoses of high-functioning autism or Asperger's syndrome in light of symptoms they currently experience or experienced during childhood. Since the cause of autism is thought to be at least partly genetic, a proportion of these adults seek their own diagnosis specifically as follow-up to their children's diagnoses. Because autism falls into the pervasive developmental disorder category, strictly speaking, symptoms must have been present in a given patient before age seven in order to make a differential diagnosis.