What are you on?

My knowledge of mythology is a bit dodgy, but I think it was a bloke called Sisyphus who was doomed to spend eternity pushing a heavy rock up a steep hill, only to have it roll down to the bottom and have to start all over again. The Dwain Chambers affair brought this to mind, as it must be something akin to what those seeking to ban illegal substances from athletics feel like. Every time they think they've made an advance, along comes some new performance-enhancing substance, and they have to start all over again. Of course, this raises the question of whether, if you can never eradicate the problem completely, you have to somehow learn to live with it. We used to make a distinction between professionals and amateurs in sport, with separate competitions for each - perhaps we should consider bringing drug-taking out into the open, with separate competitions for those using, and those not using?