Final answer:
The active chemical in psychoactive mushrooms is psilocybin, a substance known for its hallucinogenic effects and historical use in religious ceremonies.
Step-by-step explanation:
The active chemical in psychoactive mushrooms is psilocybin. This substance is extracted from certain types of mushrooms found in various regions around the world and is known for its hallucinogenic properties. Psilocybin can produce effects similar to LSD, but it is distinct from other substances such as chlorpromazine, lysergic acid diethylamide (LSD), mescaline, and diethylamide.
The ingestion of these mushrooms has been a part of various religious ceremonies, and their psychoactive effects are due to the way psilocybin affects neurotransmitter systems in the brain, particularly acting as a serotonin agonist.