But there are risks with taking hallucinogens—serious ones. Frequent users may experience episodes of psychosis, with severely altered perceptions years after they’ve stopped taking the drug. Another common effect of long-term LSD use is recurring “flashbacks.” There's even a name for the condition of having LSD flashbacks: “hallucinogen persisting perception disorder” (HPPD).
Apple, "The Doors of Perception," most of the really good Beatles records—there's mountains of evidence that psychedelics have beneficial effects.
But drugs are still drugs, and many say psychedelics, like alcohol and nicotine, can be extremely dangerous and should be monitored. In the studies cited above, the drugs were administered by a doctor in a controlled setting. That's very different from the way many people consume mushrooms or LSD.Just this description alone shows how risky unmonitored use of these substances can be:
Psychedelic drug effects cut off communications between the brain and the body, leaving the mind to expand in awareness and create its own reality. While these drug types do work in different ways, psychedelics disrupt the brain’s chemical pathways, which can be harmful when used on a frequent basis.