We always have urged people: Don't take LSD unless you are very well prepared, unless you are specifically prepared to go out of your mind. Don't take it unless you have someone that's very experienced with you to guide you through it. And don't take it unless you are ready to have your perspective on yourself and your life radically changed, because you're gonna be a different person, and you should be ready to face this possibility.

CBC Documentary: How To Go Out of Your Mind: The LSD Crisis (1966)