That's a silly question to attempt to answer 40 years later. Nevertheless, the drug problems in the USA and its creation of a world wide market in drugs is the result of both the USA, Canada and Western Europe attempting to treat the mentally ill on a community based, out-patient basis.
So you have no evidence but you'll make the claim anyway. Typical Drug War 'logic.'
From Sarah Jane Moore to Mark Chapman, to David Hinkley and Patrick Purdy, of the Stockton School yard Massacre, all were mental patients being treated at a community clinic.
And they were all pot smokers? Or are you dragging in red herrings?
Possibly and probably, but to be honest, I don't know for sure. Pot is your issue, the mentally ill on the street is mine. Once the mental and homeless are institutionalized, I really don't care what you smoke.