I believe that pot seriously damages the brain. Heavy users in their teens or early twenties who I know are impaired. I know that these guys are very intelligent, who would have been hugely successful, but the drug use has them into idiots. I am not kidding.
They may not admit it, but it is obvious. The drug changes the neural pathways and distorts personalities.
Anything that is driven into underworld status takes a change in character for the worse. There was no widespread plague of kids doping out to this degree before the marijuana bans.
"Drugs are menacing our society. They're threatening our values and undercutting our institutions. They're killing our children." -- President Ronald Reagan.