Medical researchers now claim to have evidence that longterm pot smoking can cause memory loss, disoriented thinking, and a lack of ambition; and can be at least psycologically, and perhaps chemically, addictive, with withdrawal symptoms that include anger, aggression, and irritability.
Well, like DUH.
Now we have to figure out what chemical agents make certain heavy tokers believe themselves to be at one with the plants and the animals, but treat non-pot-smoking humans as a separate/inferior life form.