I feel this falls in the error that most official medical information also falls in: Takes account of all the statistical risks and damage, but none of the benefits.
Sadly I'm just an n=1 sample, but psychedelic "over"use inoculated me to delusions to the point my beliefs (though not my emotions) are surreally stable. I don't believe I know all, but I developed a framework (much thanks to lesswrong and rationality) that is persistent even through most altered states of consciousness. No more great relevations. No feelings of going permanently and irreparably crazy. I actually miss both of them, they were very cathartic.
I did distill the lesson that LSD basically short-circuits the "true" lights very early, and compensate accordingly.
Many of these pathological patterns are actually because one glances very true things about the world, but then takes, and runs off with.
Everything IS connected to everything through causality. We do seem to live in an ever splitting multiverse. This doesn't mean we can jump around the instances, or bend spoons with out minds, no matter how much we hope we could.
Human behaviour and the world, too IS much more harsh and cruel than our normal naive notions tell us. it doesn't mean it pays out to treat every situation and every person as hostile.
Also people should realize that when they run themselves down in a stimulant binge, maybe they feel so threatened because they are in a very pitiful and vulnerable state.
I don't want to fall over the proverbial horse. Some people are just susceptible to these things in a very inherent manner and will run into them repeatedly and inescapably. The responsibility falls to others to manage these cases, as the subject will not able to.
Sorry if this feels like bashing your essay, it's my style of communication to a fault. I hope my criticism can actually used to refine your argument.
If you're prone to forming delusions, but you're good at checking your beliefs against reality, you might manage to avoid going off the deep end, but that doesn't mean escape unscathed.
Amphetamine use can make you imagine the people in your life are plotting against you. A good rationalist will notice they lack evidence and that the prior should be pretty low, but they'll still be left with whatever cognitive patterns threatened to generate that delusion.
Psychedelic use can make you believe stuff in the "all is connected" space. A good rationalist isn't going to start believing parapsychological phenomena are real because of something they experienced on an LSD trip, but they'll still be subject to the cognitive patterns that tend to make some others believe such things.
Schizophrenia can make you see corruption all around you or imagine your own persecution. On the margin, practice in rationality might be a bulwark against schizophrenic delusions (these statements have not been evaluated by the Food and Drug Administration; LessWrong is not intended to diagnose, treat, cure or prevent any disease). But while you might save yourself from believing the CIA is after you, you wont save yourself from the cognitive patterns that tend to give rise to such delusions.
When you become subject to a new bias, as long as it doesn't obviously put you out of touch with reality, it can be tempting to image that what's really happening is you're getting smarter. Now it's just the way you think, and these biases can be self-reinforcing.
Look, I know my co-workers hate me, I've seen what they say when they think I'm not looking. If my increased Adderall dose has anything to do with it, I should be happy it slapped my out of my naivete. You just want me to stop taking it because you're jealous.
A lot of the times we acquire a new cognitive pattern, it is because we're getting smarter — that's a big part of growing up, and we grow up at a formative time in our lives. How do we know which new cognitive patterns to be suspicious of? My recommendation: take the outside view.
Try to figure out where a new cognitive pattern might have come from and look at how similar patterns with similar causes have played out in other people. Amphetamine paranoia, for instance, has few accomplishments to its name, and many people under its influence arrive at beliefs that don't match reality. If the pattern arose around the time you increased your amphetamine dose, it's probably not making you smarter, and you should be suspicious of any new paranoia-adjacent beliefs.