no
Although it is impossible to know for sure, the species Amanita muscaria was likely the first mushroom used as a hallucinogen.
Hallucinogen
yes, but they were not as medically advanced as we are today
Preservative. Can be a weak local anesthetic, or sedative-hypnotic; it isn't medically used today, but has some (small) history as a recreational drug.
that is what its used for...
Yes, Marijuana is used both medically and recreationally both in the present and in the past.
hallucinogen
Yes, PCP is a dissociative hallucinogen.
Yes, marijuana is a mild hallucinogen.
Hallucinogen
its a depressant
Not sure about ancient usees, but today oxygen is used for oxygen therapy- medically. As well as at Oxygen bars for recreation.