Edited by RHYMER RIGBY, email@example.com.
Wellbutrin is the latest addition to that old and mixed family of drugs, the anti-depressants. It distinguishes itself from its siblings on two fronts: firstly, the active ingredient, bupropin, is also marketed as Zyban, a drug to help smokers kick the habit; and, secondly, as Glaxo Wellcome is keen to emphasise, it carries a 'minimal risk of sexual dysfunction' - a failing, ironically, of many other 'happy pills', including Prozac.
But there are downs as well as ups. Users claim anxiety, insomnia and memory loss as potential side-effects, and while its action has been linked to the neurotransmitter noradrenaline, no one knows exactly how Wellbutrin works. It's now available in the US, but gloomy Brits who smoke too much will have to wait until the end of next year before they can get it here.