though I hope you realize that claiming there are long-term side effects from a small amount of marijuana use is a very controversial claim.
I wouldn't claim that a small amount of marijuana use would have have significant effects. It would have minor effects. I would it in the ballpark of 'going a week without exercise' in terms of neurological impact. It would be extremely controversial to claim that frequent marijuana use does no damage, which is something I presume is mere common knowledge.
And I would confidently bet that you'd find increased well-being for both the marijuana and psilocybin groups after only one use.
You're on. Although I've adjusted my prediction slightly based on your anecdotal report. I had never heard someone report such an affect from a one time use of pot.
A pity we can't actually do the experiment.
Absolutely. This is the sort of thing that warrants far more attention. SSRIs aren't without side effects, some of which are significant. Given that there is potential for once of treatments of psilocybin and (your hypothesis) cannabis having long term effects they should certainly at least be investigated further.
I'm curious why you have so much contempt for marijuana
Contempt only for the belief that it does not come with a well known potential cost to mental health. As for actual use I don't have all that much contempt, except in the sense that I have contempt for diets high in processed carbohydrates.
personal experience, or those NIH studies about psychosis?
Most of the people I know who use pot have not done so to the extent that I could reliably say that they have damaged themselves, given that they began use before I met them. I don't know any outright abusers of the stuff. Alcohol tends to be the preferred drug of abuse in my usual circles. The effects are arguably worse, at least in some areas. Like liver damage, for example. Even more so, on the physical side, if the cannabis is not smoked, with the associated wear on the lungs. It's all about the brownies. ;)
except in the sense that I have contempt for diets high in processed carbohydrates.
I'm totally stealing this as a reason to disapprove of pot.
Human beings are all crazy. And if you tap on our brains just a little, we get so crazy that even other humans notice. Anosognosics are one of my favorite examples of this; people with right-hemisphere damage whose left arms become paralyzed, and who deny that their left arms are paralyzed, coming up with excuses whenever they're asked why they can't move their arms.
A truly wonderful form of brain damage - it disables your ability to notice or accept the brain damage. If you're told outright that your arm is paralyzed, you'll deny it. All the marvelous excuse-generating rationalization faculties of the brain will be mobilized to mask the damage from your own sight. As Yvain summarized:
I find it disturbing that the brain has such a simple macro for absolute denial that it can be invoked as a side effect of paralysis. That a single whack on the brain can both disable a left-side motor function, and disable our ability to recognize or accept the disability. Other forms of brain damage also seem to both cause insanity and disallow recognition of that insanity - for example, when people insist that their friends have been replaced by exact duplicates after damage to face-recognizing areas.
And it really makes you wonder...
...what if we all have some form of brain damage in common, so that none of us notice some simple and obvious fact? As blatant, perhaps, as our left arms being paralyzed? Every time this fact intrudes into our universe, we come up with some ridiculous excuse to dismiss it - as ridiculous as "It's my daughter's arm" - only there's no sane doctor watching to pursue the argument any further. (Would we all come up with the same excuse?)
If the "absolute denial macro" is that simple, and invoked that easily...
Now, suppose you built an AI. You wrote the source code yourself, and so far as you can tell by inspecting the AI's thought processes, it has no equivalent of the "absolute denial macro" - there's no point damage that could inflict on it the equivalent of anosognosia. It has redundant differently-architected systems, defending in depth against cognitive errors. If one system makes a mistake, two others will catch it. The AI has no functionality at all for deliberate rationalization, let alone the doublethink and denial-of-denial that characterizes anosognosics or humans thinking about politics. Inspecting the AI's thought processes seems to show that, in accordance with your design, the AI has no intention to deceive you, and an explicit goal of telling you the truth. And in your experience so far, the AI has been, inhumanly, well-calibrated; the AI has assigned 99% certainty on a couple of hundred occasions, and been wrong exactly twice that you know of.
Arguably, you now have far better reason to trust what the AI says to you, than to trust your own thoughts.
And now the AI tells you that it's 99.9% sure - having seen it with its own cameras, and confirmed from a hundred other sources - even though (it thinks) the human brain is built to invoke the absolute denial macro on it - that...
...what?
What's the craziest thing the AI could tell you, such that you would be willing to believe that the AI was the sane one?
(Some of my own answers appear in the comments.)