I agree about LSD, I find a lot of things more introspective and therapeutic, although that said, I've had some very therapeutic trips on LSD, too (and also sober). LSD is really fun and I love it. Mescaline, however, is a beautiful inward-focused, wise and loving substance. The tryptamines, such as mushrooms or really almost all of them are also quite therapeutic but in a more intense, off-putting way than mescaline. It's difficult for me to imagine having a negative experience on mescaline, it's so warm and gentle and comfortable.