Autism, rather like "Epilepsy", is a very broad descriptive term which is used to reference a wide spectrum of different behavioural patterns and syndromes of greatly varying severity which share a cluster of similar observable features. I don't therefore think it's a good idea to try to generalise specific potential triggers as applying to the condition as a whole by assuming that there is "a cause" or even "causes" that can be attributed to autism
in general. It seems more likely to me that specific autistic subtypes and symptoms have different causes; or perhaps in some cases groups of contributary factors, such as a mixture of potential environmental triggers and inherent genetic susceptibility, which will cause certain autistic symptoms to manifest in an individual once a certain (as yet largely unknown) threshold is met.
Having said that, I think the way we live now is likely to be a significant factor in the contemporary and recent rise in cases (though I don't think we should rule out the fact that there is a greater awareness of the condition and consequent willingness to diagnose either). I have difficulty believing that the environmental pollutants, pharmaceuticals, industrially altered foodstuffs and chemical additives we daily and unthinkingly consume and are exposed to (which human bodies never had to deal with over millions of years of evolution) are not going to have some kind of effect on the delicate brain of the developing fetus. Lifestyle probably has a lot to do with it as well.
I've long suspected that my nephew's autism, which is towards the more serious end of the spectrum in many respects, was triggered, besides any inherent genetic susceptibility he may have posessed, by the three following factors: His mother continued smoking fairly heavily while pregnant (she claimed it helped her deal with her very severe morning sickness which the doctors were largely refusing to give her medication for); he was born very prematurely (thus with the brain at an immature stage of development); and he spent around six months of his life in neonatal care in the hospital in consequence, much of that intensive care. I actually place a lot of emphasis on the last as a potential trigger.
Before I went into the unit to see him, I had no idea what incredibly stressful places premature baby units were, with their constant routine testing and medical intervention (much of it superfluous to actual care needs or attempting to pre-empt them); the exposed position of the baby in the incubator to facilitate medical intervention and observation; lack of meaningful
human interaction; and constant, 24 hour loud noise and bright lighting. The baby, which at this stage in its development should be in the relatively secure and peaceful environment of the womb, is subjected to this all day, every day, until it's ready to go home.
Human brain growth patterns, in which the higher cognitive areas (especially the cerebral cortex) develop late in the growth process, mean that the baby's brain is undergoing significant growth and maturation during this period when it's being exposed to massive and unnatural environmental stress. It doesn't surprise me in the least that autism levels are
much higher in very premature babies than the general population (I've seen it listed as high as 25%), and I think they really could do with eliminating the iatrogenetic factor to bring those rates down a bit. I'm sure the standard defense of these outrageously high rates is that autism is simply a natural consequence of prematurity and it's therefore out of their hands: but they used to think that of the high rates of blindness before they realised that the overuse of oxygen therapy was causing oxygen toxicity and retinal damage, significantly exarcerbating the problem.
I don't doubt that the neonatal units are very effective at fulfilling their intended function of keeping the delicate premature newborns alive; I just wish they'd design the units and their operating proceedures with more attention to the child's future developmental needs rather than seeing their roles so narrowly. If they're sucessful the child has a whole lifetime ahead of it outside the unit, and that life is going to be a lot easier for both the child and its parents without the symptoms of autism.
/rant over
Oh, and I don't know how the heck they managed to get those kids to sit still in order to put needles in them either. It currently takes five determined adults (at least three of them medical professionals) to give an injection or blood test to my nephew, who is seven. And even then it's apparently a struggle and will probably have to be attempted several times before success.
