Earlier quoted context omitted.
> There have been entire monasteries full of people who spend many hours a day meditating for thousands of years. They don't seem to be mentally unhealthy on the whole, Not to be snarky (ok maybe a little), but they do believe in unprovable beings on some "higher" plane of existence...
You just called billions of people mentally unhealthy. Not so much snarky as unnecessarily mean.
It's unnecessarily mean if it's not true or, arguably, if there's nothing they can do about it. But if it's true and there's something they can do about it, then not saying it is being unnecessarily mean.
The Buddhist prescription for how to get better (from common garden-variety self-delusion, not schizophrenia) is called the Noble Eightfold Path, and a large dose of meditation occupies an important place in it. Other important ingredients traditionally include material renunciation, strict nonviolence, celibacy, abstinence from alcohol, honesty, politeness, etc. https://en.wikipedia.org/wiki/Noble_Eightfold_Path
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† And, arguably, Christianity.