Environmental Factors in the Causation of Autism
Wednesday, November 12, 2003 (19:06:43)

Posted by Sylvia

Paper by Paul Shattock

Introduction

It is universally accepted that there is a considerable genetic element in the incidence of autism. The occurrence of so many families where multi-incidences of autism and related spectral disorders exist is compelling evidence.

However, this is probably not the whole story. Even the strongest proponents of genetics research are now beginning to talk in terms of "genetic fragility or predisposition". If, as seems highly possible, the incidence of autism is increasing, then factors other than the purely genetic must be implicated.

Increasing reported levels of autism have been reported from many parts of the world but, as has been pointed out on a number of occasions, this may reflect no more that increasing awareness of the disorder and changing diagnostic criteria (Gillberg 1998a; Wing 1996).

However, two recent reports (California (1999); Taylor (1999)) have highlighted what would appear to be very significant increases in the incidence. It must be remarked that the latter was intended to demonstrate that the introduction of the combined Measles, Mumps and Rubella (MMR) vaccine was, in no way, a factor in this increase.

Many of those who actually read this paper were unable to reach the same conclusions as the authors but, even so, there was a dramatic (1,700%?) increase of reported incidence between 1979 and 1992 (birth dates). The California (1999) report showed a 273% increase, in the State of California over a similar (but not identical) period of time.

Informal and unpublished data from many parts of the UK and other parts of the world are showing similar increases. It is alleged that parallel, staggering increases in incidence are occurring in similar disorders such as dyslexia; Attention Deficit Disorder (ADD) which may be combined with hyperactivity (ADHD).

Indeed, reports from the US and Australia suggest that 10% of children of school age are currently taking Ritalin to ameliorate the symptoms of ADHD. In other circumstances, these increases would be regarded as an epidemic and worthy of considerable research but, so far, environmental factors have been completely and utterly ignored by governmentally funded agencies within the UK.

If these increases are, indeed, genuine then there must be factors, additional to the purely genetic, which are involved and which may trigger the problems.

It may be of interest and relevance to examine other diseases or disorders which have, in comparatively recent history, increased or decreased markedly in incidence. There could be lessons which can be learned and which could be used to explain the apparent upsurge in incidence of the disorders described above.

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