I'd taken LSD a few times in my 20's. Fun, but nothing amazing (though it did spoil all other social drugs for me - what's the point of getting high if it's not at that level?)

Then 10 years ago (so in my 40's) I took it again at a bush rave. At the time I was in a deep clinical depression, regularly feeling suicidal, fighting alcoholism, it was a tough time. During the trip, I saw a vivid vision of a version of myself as I could be if I got my shit sorted out and sobered up. I really liked that vision/version of myself, and it stuck with me afterwards (unlike most of the stuff on acid trips).

That vision became my beacon. It took me another 5 years or so to work through the depression with therapy. I still struggle with the booze (but it's much, much more manageable now, and no psychotic episodes any more, yay!). But knowing that there was a "healed" version of me, and what that looked like, and that I could be that person. That was powerful. Literally the light at the end of the tunnel.

So yeah, that's my "hallucinogens helped my mental health" story :)