A hallucinogen can change the way a person sees and interprets reality. There are two types of hallucinogens: natural and synthetic. Natural hallucinogens include some types of mushrooms and peyote, and marijuana. Synthetic hallucinogens include LSD, PCP, and so-called designer drugs such as MDMA (ecstasy). Readers learn about the reasons people use hallucinogens, about the effects on the brain and body, and about abuse, treatment, and recovery. Drug...