Will the mephedrone ban cause more drug deaths?

Fascinating analysis on the Straight Statistics blog suggests that the now-banned drug mephedrone may have saved lives when it was legal.

Professor Sheila Bird, a statistician with the Medical Research Council at Cambridge, has been trying to understand why, after steady rises, there was an unexpected but significant fall in cocaine-related deaths in the first half of 2009.

“One possible explanation,” she writes, “might be that cocaine- and ecstasy- users were switching to a less dangerous drug, mephedrone, in and before this period”