This is a story about a man who lived in a house. Here it is:
The house was a lovely thatched cabin, situated in a wooded valley between two little hills, set against the spectacular scenary of a snow-capped mountain. He'd been born there, and he'd lived there all his life.
One day, there was a knock on the man's door. He opened it to find two official-looking people carrying clipboards, with serious expressions on their faces.
"Hello, sir. We are officials from the Ministry of Mountains. Sorry it took us so long.""Oh... excuse me?", the man replied, puzzled."We're very sorry we didn't get here earlier.""I'm afraid that I don't know what you mean. I wasn't expecting any...""Hmm. Let me explain. The Ministry of Mountains exists to help people who live on mountains. So, you see, we're here to...""Ask for directions to the mountain? It's about 10 miles down the road. Just look up - you can't miss it."
The official looked unamused. "No. We're here to help you, sir.""Help you to cope with the rigors of mountain living!" the other chimed in, helpfully."But... I don't live on a mountain.""I'm afraid you do. Look - " and the first official unfolded a large map. "Do you agree that there is a mountain, here?" and she pointed to a spot 10 miles down the road."Yes. Actually I just told you about i...""...and, do you agree that you live - here?" "Of course, but..."
"So you do live on the mountain. The very ground beneath our feet right now is part of that mountain nearby.""No it's not." The man protested. "This is a valley, miles away. I mean just look outside. We're clearly not on a mountain now, are we?" "How old fashioned. That's what we used to think. But, thanks to advances in geology, we now appreciate that these hills and valleys are merely a part of the mountain." "Yes!" the other said, whipping out a textbook and becoming increasingly enthusiastic. "You see, a mountain is merely a mass of rock, and this rock extends underground for a considerable distance... It's impossible, really, to draw a line on the map and say categorically, this side is mountain, this isn't. So 'mountains' are an arbitrary construct. 'Hills' are likewise just protrusions of the underlying mountain and..."
The man was even more confused now. "Umm... well, I suppose, technically...but...""...so yes, so you do live on a mountain. And we know that this is very difficult. You're exposed to all kinds of dangers like blizzards, altitude sickness, avalanches...""Not really. It's nice here. It doesn't even snow most years.""That's unlikely. You agree that mountains have blizzards and avalanches? Right. And you earlier agreed that there's no dividing line between you and a mountain. So logically...""Er...""So you are in danger! Don't worry, though. We're here to help. To start off with, we're going to reinforce your house with six tons of cement, to protect you against rockfalls. The construction crew will arrive tomorrow morning. Now, as for those blizzards..."The man had had enough of this."This is absurd. Now look - there is a guy who really does live on top of the mountain in a rickety old shack. Old Grandpa McHermit. He might actually need your help. I don't. Get out! And if I see anyone with a bag of cement tomorrow morning, I'll shove it right up their..."
As you may have guess, this story is a metaphor. There is a movement in psychiatry at the moment, away from a 'categorical' view of mental illness towards a 'spectrum' view. Mental disorders are not things you either have or don't - defined according to some arbitrary cut-off. Rather, they're things that everyone has, to some degree.
This has already happened, or is happening, to autism, schizophrenia, bipolar disorder, personality disorders, and more.
Now, the "spectrum" or "dimensional" approach has much to recommend it. It's true that diagnostic cutoffs are arbitrary. It's true that the categorical approach doesn't capture the true degree of variation that real people display.
My worry is that these new "spectra" are, in practice, merely the old categories, just bigger. We still think of people as being ill or not-ill, although we may call it on the spectrum or off it. Worse, we still think of "ill" in the same way as we used to i.e. as referring to the most severe end of the spectrum. The only difference is that we've expanded the old category of "ill" to cover more people.
This is evident in the fact that we still use the old categorical labels. It's the autism (or schizophrenia or bipolar) spectrum, even though "autism", in the old sense of a discrete disorder, is now supposed to be just one extreme of that spectrum. Yet the point about an extreme is that it's unusual, so why call it that?
We don't call the rainbow the red spectrum. We don't call height the midget spectrum. We don't call hills part of the mountain spectrum.
The point is, we really think of color and height and altitude as spectra, not as approximations to an extreme point, and that's good, because they are. Now it might well be possible to think of autistic or bipolar traits in the same way - but not if we call them autistic and bipolar traits. And not if we just rename them, while keeping the mental associations the same.
Not unless we can find a way of referring to what's currently called the autism spectrum without making anyone think of autism when they hear it. Similarly for "bipolar" and all the rest. Until we get to that point, there's a real risk that "spectra" will just be big categories.
Edit: This post has been very kindly translated into Hebrew over at the alhasapa.com blog.