I liken doing psychedelics in late adolescence to reading philosophy in late adolescence. Unfortunately late adolescence is the period where the majority of both psychedelic and philosophical experimentation happen, when both of these are much more useful after gaining some life experience.
If you haven't even spent time working on or struggling with your own depression and isolation, and are in fact still quite tangled up in the formation of these issues, psychedelics don't have much to offer you other than "fun". Likewise reading Nietzsche as an adolescent, you miss many of the subtleties that make his work truly revolutionary, for example misreading "god is dead" a proclamation of some sort of victory against religion, when Nietzsche is much more concerned about our loss of meaning. You can't really get at what Nietzsche is worried about until you've had your own, serious struggle with meaning as you get older and the reality of death hits you much harder than any adolescent can imagine.
As an adolescence you're still rapidly formulating your world view, there's not a whole lot to shake up that isn't all ready rapidly changing. An adolescent will learn far more by interacting closely with a group of people they normally wouldn't, or wandering around parts of a city they normally never go to, than doing any psychedelics. It's not to say they shouldn't experiment with psychedelics and read lots of philosophy, but these won't be really impactful until later.
I highly recommend everyone in their thirties and later revisit both psychedelics and philosophy. There's a lot more there than when you where younger.