That's because it doesn't exist. Most the stoners I've known in life were self medicating for mental issues. It probably started out as something fun to do, but the fact is, it works.
I've watched someone smoking pot to stop many seizures in someone with bipolar w/schizo tendencies. He was my brother, and had some real mental issues from childhood. The weed "stopped my ticker", he would say. His "ticker" was the onslaught of all these thoughts in his head. When he smoked, the "ticker" slowed down to a point where he could actually deal with what was happening in his head. Make no mistake - he had screws loose to begin with. The wild part was that when he used it, the normal paranoia his brain created was reduced greatly.
Had the reverse issue with a person who was quite easy to get along with until the person decided to switch from tobacco to pot.
After a little while on pot the paranoia kicked in and quickly consumed the person’s life.
Eventually this person attacked me, tried to blind and kill me because of all these fantasies.
Nope, never going to have anything to do with a dope head again, and wouldn’t have if I had known she was going to violate our agreement by using it.