Apologies, by the way, in case any of this is inappropriately confessional or too dull for anyone else! I've been thinking about it a lot recently (I do anyway, naturally) because someone at work actually guessed that I have OCD from watching my peculiar rituals, which rather shook me because, although I do peculiar rituals literally all the time, I normally hide them pretty well and people don't realise. Perhaps I'm getting worse.

I'm not sure whether things are over or under diagnoised. Does having a label help matters? I know that I've got many traits which are typical of many diseases (my thinking pattern is very common in people with schizophreina, I have depressive phases, I'm mildly dyslexic) and I'm sure if I was analysed fully I'd have all sorts of nasty disorders. But thankfully they don't affect my life much, and I consider myself to be fairly sane. So does diagnosing mild ADD, mild OCD or mild Aspbergers help? There's no definate treatment (although congitive therapy can help, but cognitive therapy can help a lot of people) so why the need to label it?

What Dunx describes above is almost exactly what happened to me but in reverse I think. The OCD arose because I was depressed and would obsess on tiny things, believing absolutely that those things were the cause of my depression and if only I could sort them out I'd be happy. When, of course, I didn't sort them out I became more depressed, and so on and so on.
I can quite strongly reccomend hypnotherapy for the treatment of OCD. I wouldn't call it a cure but it sure helped me.
As far as diagnosis goes I don't think with these things that it's that clear cut. It's simply what you might call a personality trait, and we all exhibit different personality traits in differring amounts. Some people are talkative, some are fly-by-night, some are obsessive. I think we assign the term 'disorder' when one of these traits goes to an extreme such that it interferes with the normal day-to-day running of our lives. If we had a sound scientific way of actually measuring the extent to which each trait applied to us, the the term 'disorder' would be redundant.

[Lib] I think the label does help. One of the things that helped me (and is still helping me) pull up out of the spiral of OCD was the fact that I could give it a name. I know now that I have an obsession, and that makes it less real so that I can actually control and sometimes ignore it. When you're in the depths of OCD you fully do not realise that you are obsessing, you just think that there is nothing else to life.

[st d] I can listen to anyone, but I hate talking.
[Lib] Naming a thing (and to some extent inventing the thing by the process of naming it) can cut both ways. The Asp/Aut/AD(H)D concept is now out there to a degree to which it wasn't, not many years ago. This lets people use it as a convenient club to beat people they can't deal with, but also lets others recognise themselves in it and make contact with each other. I've read alt.support.autism on and off, and there's a lot of very interesting, politically conscious stuff goes by. In fact, a lot of the politics is exactly the same as for being gay, black, deaf, or female. For pretty much any position that has ever been taken on any of these issues, change the specifics and it would be something that someone has said about any of the others.
[BM] Anyone who enjoyed "Curious Incident" might also be interested in Elizabeth Moon's Speed of Dark, an SF novel in which the central character is autistic. The characterisation is quite similar.