Now, I know you people are true academics, so somebody find the study carried out under the auspices of New York's La Guardia administration in 1944, in answer to the notorious Harry Anslinger's absurd propaganda, and give us a blue clicky to it.

Oh and there is a superb documentary film about the whole subject, voiced over by actor Woody Harrelson, but I can't recall the title of it for the life of me . . . 'cos of my advancing years, not what you were thinking. Perhaps, one of you could provide the name, for the education and delight of the group.

And you might wish to look at the following:-

http://www.pbs.org/wgbh/pages/frontline/shows/dope/etc/cron.html