CNS DEPRESSANTS: anesthetics, barbiturates, ethanol, tranquilizers, volatile inhalants, marijuana (tetrahydrocannabinol)
CNS STIMULANTS: amphetamines, caffeine, cocaine, nicotine
HALLUCINOGENS: lysergic acid dimethyltryptamine, mescaline, phencyclidine
OPIATES: codeine, heroin, methadone, morphine