In a comment on my posting about Newsweek’s autism test a few days ago, Laurent said,

I do not understand why we would categorize people based on test. 50 questions to define a human brain, this seems a little bit simple.

Laurent is right, of course. That quiz was designed for regular people to take as an entertainment. Real diagnosis of autism is a much more nuanced procedure, but perhaps not as much more as you would think.

For example, here’s an experimental PDD screening questionnaire. It contains 44 questions, answered on a five-point scale. The existing standard diagnosis protocol is hard to find online, but here’s an informal summary.

The key phrase in the diagnosis is “6 of 12 symptoms”. This means two kids can both be diagnosed with “autism”, and have no symptoms in common. This is ridiculous.

Imagine we didn’t know how legs and feet really worked inside. Any time someone couldn’t walk, we’d say they had “Can’t Walk Disease”, but to make it sound more official, we’d call it “anambulism” (from the Latin root “ambul”, to walk). If you twisted your ankle, you’d be diagnosed with anambulism. Torn achilles tendon? Anambulism. Pulled hamstring? Anambulism. Broken leg? Severe anambulism. Plantar warts? Mild anambulism.

Of course, the diagnosis of “anambulism” is ridiculous, but only because legs and feet are relatively straightforward devices, and we can see what is really preventing them from working properly. Because we understand the mechanisms, we can provide appropriate and effective treatments for each malady. We can deal with the different underlying problems differently.

But the mind is not straightforward at all. We have no idea how it works, and we have no idea what’s preventing it from working when it doesn’t. When a child behaves in certain bizarre ways, we say he has “In a World by Himself Disease”, but to make it sound more official, we call it “autism” (from the Greek root “aut” for self). The diagnosis is about observable behavior. Many treatments are about modifying observable behavior, or are scattershot techniques that sometimes work, but we don’t know why.

There are other diagnoses besides “autism” for similar afflictions, like Asperger’s and PDD (pervasive developmental disorder), but these are mostly just measures of degree, not of kind. They label different points on the same spectrum, and choosing among them seems to have as much to do with the practitioner’s preference as with real science.

I hope in 50 years we’ll look back on this thinking and chuckle at how we could have been so simplistic. We’ll have split “autism” into at least four or five separate diseases, each thought of as different. Maybe we’ll understand causes. Maybe we’ll have effective treatments. Maybe “autism” will go the way of “anambulism”.