Pervasive Developmental Disorder

An umbrella-categorization for several related disabilities, of which Autism is the most well known. Sometimes also called PervasiveDevelopmentDisorder and often abbreviated PDD.

Definition

From http://www.autism-society.org/ -

Autism is a complex developmental disability that typically appears during the first three years of life.
The result of a neurological disorder that affects the functioning of the brain, autism and its associated behaviors have been estimated to occur in as many as 1 in 500 individuals (Centers for Disease Control and Prevention 1997).
Autism is four times more prevalent in boys than girls and knows no racial, ethnic, or social boundaries.
Family income, lifestyle, and educational levels do not affect the chance of autism's occurrence.

Note - '1 in 500 overall, but four times as prevalent in boys' implies a frequency of about 1 in 300 for boys and 1 in 1200 for girls. Can anyone give further statistics relating autism to other factors, such as whether combined vaccine (MMR) has been given?

[No, if you had 2500 kids, assuming 50/50 girls/boys, you'd have 5 with autism, 1 girl and 4 boys. Would we say that's "1 in 1250 girls and 1 in 312.5 boys," or do we prefer "1 in 1250 girls and 4 in 1250 boys" or even "1 in 1250 girls and 2 in 625 boys"?]

No. Boys/girls are not 50/50. My arithmetic was correct.

I recently read that the MMR vaccine was cleared once again of anything to do with this.

But... http://www.telegraph.co.uk/news/main.jhtml?xml=%2Fnews%2F2002%2F06%2F23%2Fnmmr23.xml. Also Dr Paul Shattock, director of the Autism Research Unit at Sunderland University, on the basis of an unpublished study of 4000 cases, says the evidence that MMR is linked to autism is strong, but not conclusive.

Unpublished studies aren't worth the paper they are written on. True, but as it's his study, I imagine he will publish it in due course.

The following is extracted from an article published recently in a British newspaper (http://www.dailymail.co.uk/pages/live/articles/health/healthmain.html?in_article_id=376203):

"When scientists first raised fears of a possible link between mad cow disease and an apparently new, variant form of CJD they had detected in just 20 or 30 patients, everybody panicked and millions of cows were slaughtered," said Dr Fletcher.

"Yet there has been a tenfold increase in autism and related forms of brain damage over the past 15 years, roughly coinciding with MMR's introduction, and an extremely worrying increase in childhood inflammatory bowel diseases and immune disorders such as diabetes, and no one in authority will even admit it's happening, let alone try to investigate the causes."

He said there was "no way" the tenfold leap in autistic children could be the result of better recognition and definitional changes, as claimed by health authorities.

"It is highly likely that at least part of this increase is a vaccine-related problem." he said. "But whatever it is, why isn't the Government taking this massive public health problem more seriously?"

His outspokenness will infuriate health authorities, who have spent millions of pounds shoring up confidence in MMR since Dr Wakefield's 1998 statement.

[Dr Fletcher is a former Chief Scientific Officer at the Department of Health in the UK.]

Re: "He said there was "no way" the tenfold leap in autistic children could be the result of better recognition and definitional changes" -- I believe that statement has become more widely accepted, but it does not follow that vaccines are necessarily the cause.

The thimersol component of vaccines is, IMHO, probably going to turn out to be a bad idea (because thimersol-based contact lens solutions makes me feel like acid in my eyes, so I can't buy the party line on the subject) -- but there have been a reasonable number of studies indicating that thimersol is not the cause of the sharp rise in autism, regardless of how bad it is in other respects.

Kind of like standard metal dental fillings based on "amalgam", which incorporates mercury. There's no way that this is a good idea, no matter what the establishment says to fend off vast class-action law suits, but it's not as bad as it sounds, either, since elemental mercury is not well-absorbed by the body (but it's not innocuous, either, so I've had 100% of my amalgam fillings replaced with modern non-metallic substitutes over the years, and I highly recommend the same to everyone -- but gradually, not in a panic).

Meanwhile fear of vaccines has become widespread enough to cause many previously "conquered" diseases, the worst of which is perhaps polio, to have become a serious worldwide health threat once again.

So Dr. Fletcher is directly hurting children worldwide, and at a much higher rate than the occurrence of autism!

-- DougMerritt

Relevance

There has been some learned speculation that some of the genetic components of PDD may have some correlation with the engineering and science communities. Many engineers exhibit behaviors very similar to autism, and some researches have suggested there may be a slightly higher propensity for engineer fathers to have children with PDD than for the non-engineering public.

More Info

A popular portal for getting additional information about Autism, PDD, and treatments is http://www.autism-resources.com/

Within the past year, there was an article reference on SlashDot about an apparent surge in the number of autistic children in the SF Bay area, attributed to the SiliconValley geek population, where there was finally a large enough number of male and female geeks to produce markedly more kids with whatever genetic markers for autism from both parents.

And here I thought you were talking about software development projects. (Hmmm... Maybe you are. ;-)