As Wikipedia puts it:
I read that Siberian tribes use A. muscaria (the common "fly agaric") to get high, even drinking each other's urine where the active stuff gets concentrated. (Blargh…)The genus Amanita contains about 600 species of agarics including some of the most toxic known mushrooms found worldwide, as well as some well-regarded edible species. This genus is responsible for approximately 95% of the fatalities resulting from mushroom poisoning, with the death cap accounting for about 50% on its own. The most potent toxin present in these mushrooms is α-amanitin.
But my comment was about the mushroom gatherers!