Psychoactive drugs are chemical substances that affect the brain functioning, causing changes in behavior, mood and consciousness. While these drugs can be used therapeutically to treat both physical and psychological disorders, they are also used recreationally to alter mood, perceptions and consciousness.
Stimulants are a class of psychoactive drug that tend to increase activity in the brain. These drugs can temporarily elevate alertness, mood and awareness. While some stimulant drugs are legal and widely used, all can be addicting. Drugs that are classed as stimulants include caffeine, nicotine, cocaine, amphetamines and some prescription drugs.
Psychedelic drugs, or hallucinogens, are psychoactive drugs that affect thinking, alter moods and distort perceptions. Drugs that are classed as psychedelics include marijuana, LSD, psilocybin (derived from a type of mushroom) and mescaline (found in the peyote cactus).