People in New York are routinely denied pistol permits for taking ambien or chantax but I think that is because NY will do anything to suppress 2A rights. Younger people medicated for ADD or mental illnesses certainly needs to be looked into further.
Alex Berenson has been writing a lot of articles lately saying the evidence suggests that the use of the high potency marijuana that's out there these days is causing some psychological problems and leads to increased violence.
__________________
"Unlearning is the highest form of learning"