Okay. This thread is full of all kinds of wacky stuff. I think maybe I should speak out and clear up a few things.
Magic mushrooms (psilocybe cubensis) do not make your brain bleed. At all. Ever.
Mushrooms also are not poisonous, believe it or not. Everything in this universe is toxic in large enough amounts, even the citrus in an orange. A "lethal dose" (or the LD-50) of that psilocybin (of which it's all converted to psilocin in your body) is too much for any human being to consume. You just can't eat that many shrooms, no matter how much you can stand the taste.
LSD cannot hurt you. What it can affect is your mental state- usually for better, but not always. LSD can be incredibly positive for a person, as long as they are psychologically and emotionally stable. If you know what you're doing, and you have the perfect set and setting, you're almost guaranteed to be fine.
"Flashbacks" are not quite the Vietnam-style flashbacks you hear about, which is usually post-traumatic stress disorder. "Flashbacks" from psychadelics are actually called Hallucinogenic Persisting Perception Disorder (or HPPD, for short), and while far from being unheard of, is NOT common. However, even one does experience HPPD, it's nothing to worry about.
You know how when you sometimes smell things and it reminds you of a certain VERY vivid memory? Well, this is what HPPD is. Something you experience later reminds you of some thought you had in your altered state of mind, and you partially enter that state of mind for a moment. You're remembering; it's just that this particular memory happened when your perceptions were completely altered. Doesn't last for but a few moments, and it always goes away for good after a little while. It doesn't interfere with everyday life (even though there are occasionally visual effects), and is more of an annoyance than anything. Most people never experience any symptoms of HPPD.
I can't believe all of this bullshit false information that's so widespread in our society. I blame Reagan, mainly. So many blatant lies have been spread about these drugs (and marijuana) to villify them, and keep them illegal. I mean... how many of you are D.A.R.E. graduates?
~Ethno