Antipsychotic drugs have been used clinically for approximately 50 years. Reserpine and chlorpromazine were first drugs found be useful in schizophrenia. The term "antipsychotic" is used to describe a group of drugs that has been used mainly for treating of schizophrenia, but also is effective in some other psychoses and agitated states. The dopamine hypothesis is the most fully developed of several hypothesis and is the basis for rational drug therapy. However, the dopamine hypothesis is far from complete. Typical antipsychotic drugs have a wide spectrum of central nervous system, autonomic and endocrine effects. The most recently introduced antipsychotics are at least as potent in inhibiting 5-HT receptors as they are in inhibiting D receptors. A rational choice of antipsychotic drugs may be based on differences between chemical structures and pharmacological differences. No basis exists for choosing drugs for the use against selected target symptoms, as there is no evidence of specificity in their effects.