Ask your GP whether you might have ADHD and you may well find he turns from his usual, er, charming, authoritative self into a twitching, head scratching bundle of uncertainty.

To understand why, we have to start with ADHD in children. This is a much more familiar concept, yet even this polairses opinion. There are those who think it's a significant and under diagnosed illness which isn't taken seriously enough by health professionals. And, at the other end of the scale, are those who fear we're simply medicalising normal variations in behaviour and using medication where tolerance, patience or some firm parenting are required.

As ever, the truth is probably somewhere between these two extremes. But it's understandable that ADHD is a controversial issue, given the emotive issue of medicating children, the variation in labelling rates in different countries and the fact that, although there are accepted guidelines to help doctors, the diagnosis is inevitably a bit subjective.

Now chuck adulthood into that particular mix and you have a whole heap of extra problems. Such as the fact that a key diagnostic criterion is that symptoms must have started before the age of seven. Can you remember that far back? Then you have to bear in mind that all sorts of other factors can affect adult behaviour, from personality, through stress and mental illness, to drug and alcohol abuse.

Plus the point that, and I'm obviously talking generally here, adult patients sometimes prefer to have a medical excuse for their behaviour as it may entitle them to, say, benefits or leniency.

So speak to a US specialist and he will probably tell you that, of the kids with ADHD, anything from 15 to 70% go on to experience similar problems as an adult and that it, if necessary, it can be treated with medication or non drug methods such as counselling, tutoring and coaching.

Ask a UK GP and you'll see the picture I painted above. Whether this means the Americans are leading the way or leading us up the garden path, who knows?