I’m an obstetrician caring for worried mothers. They’re worried about things that might put their developing foetuses at risk for a whole range of issues and ask me for advice. Obviously I’m neither a paediatrician nor a child psychologist, so questions about autism leave me alone in troubled waters. There are so many rumours of risk, so many studies that seem to implicate everything from diet to anaerobic exercise in pregnancy, vaccinations to mercury in calcium supplements.
I wish I knew more about autism; I wish I knew anything indisputable about it… Well, that’s probably a bit harsh. I know that it’s now referred to as ASD (Autism Spectrum Disorder) and that it’s a neurodevelopmental disorder with problems in at least two areas: social impairments –things like communication and interaction- and behaviour abnormalities like repetitive patterns of activities and that sort of thing. But it all seems rather vague. Especially the social components. At the severe end of the spectrum it’s an unmistakable impairment, and yet at the milder end…
It may be a sensitive set of criteria that bundles all the right things in it, and yet it’s rather spotty on the specificity. An example might help. Let’s say you’re a fisher and you want to improve your ability to catch salmon so you’ve designed a special net. You pull it up and there are a hundred fish in it, so it works –it catches lots of fish, but only one salmon. But, it did catch a salmon so it’s sensitive for salmon, but not very specific for them.
I also know the DSM-5 criteria of ASD –I’ll quote them from a more readable source: the 2014 UpToDate data base we have in our hospital. ‘ASD is characterized by 1. persistent deficits in social communication and interaction (eg. deficits in social reciprocity; nonverbal communicative behaviors; and skills in developing, maintaining, and understanding relationships) and 2. restricted, repetitive patterns of behavior, interests, or activities.’ They also say that the symptoms must be present early in childhood development, but may not become manifest until social demands exceed limited capacities. And there are three levels of severity rated separately for social and behavioral characteristics.
Okay, I understand those criteria –sort of- but coming from a medical specialty that is used to more concrete, objectively provable, and investigatable symptoms, they still seem rather vague. And there remain the difficulties that I have with including the milder, vaguer, less impaired end of that Bell curve distribution of characteristics –the end that may include variations of normal, idiosyncratic behaviors which may represent other issues –parental, social, even poverty-related stresses that might impinge on the child’s behavior.
I suppose it’s the boundaries that trouble me. There seems to be a wide variability of the reported prevalence of ASD and some indication that it is increasing of late, perhaps related to changes in definition as well as increased awareness. But how valid is that?
I’m all for increased awareness of ASD, just as long as we can be sure it is ASD that we’re aware of. This is important for interpreting the studies that purport to assess various causes of autism. For example, a BBC article reported a study from the Harvard School of Public Health which implicated air pollution as yet another cause. But, as the article suggests: ‘Experts said pregnant women should minimize their exposure, although the link had still to be proven.’
Good advice, I’m sure –pollution likely has many adverse effects on a developing foetus. One more wouldn’t be much of a surprise. Avoid pollution when you are pregnant by all means. But place that in the context of a pregnant woman who lives in a city where she cannot avoid it, and then add the additional worry of a possible link to autism in her unborn baby and you have sewn the seeds of an intractable anxiety. Helplessness. Despair. The fact that it is as yet unproven gets buried in the message; the statement that it is biologically possible does not.
As the aforementioned UpToDate 2014 data concludes: ‘The pathogenesis for ASD is incompletely understood. The general consensus is that ASD has a genetic etiology, which leads to altered brain development, resulting in the neurobehavioral genotype. Epidemiologic studies indicate that environmental factors account for few cases.’
I realize that there is a fine line between informing the public, and frightening them unnecessarily (or inadvertently), and I recognize and accept that we should all have the right to know what is being said in scientific circles about topics that affect us. Clearly it is difficult to balance whether or not to publicize information that is still in the process of being assessed and integrated into a coherent and testable theory, versus information that has been collated into a more accepted and validated model, but I think it would be a sensible, albeit challenging, step. It is a serpent’s egg, and reminds me of the warning of Brutus in Shakespeare’s Julius Caesar: ‘a serpent’s egg, which, hatch’d, would as his kind grow mischievous.’
I’m certainly not advocating censorship –maybe just awareness. Prudence… Judgment.