The following year he contributed to a paper that came to the conclusion that alcohol was a more harmful substance than cannabis, LSD or Ecstasy.

ECONOMIST: Plain speaking on a highly coloured issue

Over the next three years, 600 treatment centres are to be set up to tackle dependency on any kind of harmful substance tobacco, alcohol and psychotropic medicine included.

ECONOMIST: France

Last year, Home Secretary Theresa May was allowed to make instant 12-month bans on "any substance deemed potentially harmful", in a measure to control legal highs.

BBC: Legal highs 'worsen mental illness', says Devon mother