ABSTRACT
Stimulants are drugs that increase neural and behavioral activity. They enhance mood, increase alertness, increase heart rate and blood pressure, and reduce the desire to sleep. A number of these drugs are in common usage. These include caffeine and nicotine. Depressants are drugs that cause a general decrease in neural and behavioral activity. They include the minor tranquilizers, like barbiturates and benzodiazepines, and alcohol. All have, as one of their actions, modulation of the gamma-aminobutyric acid (GABA) receptor. The inclusion of alcohol as a depressant may seem counterintuitive, as most of us use it as though it were a stimulant. The psychedelics are also referred to as the hallucinogens because this is their major effect. They include cannabis, lysergic acid diethylamide (LSD), psilocybin mushrooms and methylenedioxymethamphetamine (MDMA). The antipsychotics are really two classes in one. One type of antipsychotic includes drugs that are used to treat schizophrenia whilst drugs of the other type are used to treat the affective disorders.
