> Almost everyone that I meet who has done considerable, or even moderate, amounts of psychedelics has clear and obvious personality changes. Personality is a poor word to use, but something like their disposition, "hippy" attitude is extremely common.

How many samples have you based your conclusion on? Did all/most members belong to one common group of people (your subsequent comment suggests yes). Is it safe to assume all individuals will adopt this style of thinking, and to a similar degree that you've experienced?

> So much so that I think these drugs cause long term physical damage to peoples cognitive faculties.

May cause (I suspect you know this, but just making note of it).

> The most productive and successful people I meet almost always have been mostly sober their whole life, exhibiting balance and clear headedness.

How do you know they have been mostly sober their whole life?

> If psychedelics are doing any good, it is because those who are taking them are already so broken, any kind of change could be construed as positive.

This is a theory, with little if any supporting evidence (I suspect you know this, but just making note of it). My point is, stating theories as facts can alter the mental models of those who read your comments (which is likely the sort of thing going on with the group of friends you observed)

> Society tells us that anecdotal evidence is false, but that's brainwashing.

Here I very much agree.

> I can see with my own two my eyes what drugs do.

What drugs can do, as you've interpreted, in a very small set.

> Most likely certain areas of people brains are dampened or flattened by these drugs, and so if youre and anxious person, maybe you experience "relief", but that comes at a cost.

It comes at a cost sometimes. How frequent this is, and to what degree, is unknown. (I suspect you may know this, but here I am less confident).

> its very common for people on hacker news and elsewhere on the internet to argue against being able to extrapolate truth from subjective experiences.

Very much agree, and this thinking is so clearly incorrect that is frustrates me to encounter it so frequently among rational people.

> But like I was saying, what I have seen has been that psychedelic effects on peoples brains are often deterministic, many people who have taken too many end up with very similar psychological profiles and dispositions. Clearly there is something going on there. In some ways, part of the angst in my post arises from all of these different news articles popping up that talk about the positives of psychedelics, when neither the people writing the articles, nor those reading them probably know very many people with any experience.

I agree. These are powerful substances, are often taken far more lightly than they deserve, and opinions expressed on forums often lack epistemic humility.