The University of Birmingham has rediscovered selegiline after reviewing its use and efficacy in 17 trials, which involved a total of 3,525 patients. Most patients showed improvements in mobility and general lifestyle activities compared with those on a placebo. Better yet, the drug is cheap and readily available.

So why did it suddenly fall from fashion? Oh, it was something to do with a study in 1995 that found it killed 57 per cent of those taking it.