Maybe I have a different perspective working in healthcare. People with mental illness tend to self-medicate with whatever is available, so you can’t lump dynamite and rope together with psychoactive drugs as the degree of actual harm is a different order of magnitude. As always, with any libertarian approach to regulation, it’s vulnerable people who suffer (mentally ill, poor, children) for the ideals of others. I find this is rarely a good deal in the final analysis.
I have a couple of psychiatric diagnoses so I am not unaware of the concerns of the mentally ill. People like me know to be very cautious with medicine, prescribed or otherwise. It should have a say in whether I should be locked up or what substances I feel I can safely use.
I think there's a problem that we can agree on and that is early detection and treatment of mental illness in teens before they get their hands on an AR-15 or LSD. As a culture, America is very neglectful in this regard.
I’m not sure what other options there are. Illegal: people go to jail. Legal: people who shouldn’t take these drugs will have access. I’m certainly open to suggestions though.
