Antipsychotic Drugs

The term psychosis refers to a variety of mental disorders characterized by one or more of the following symptoms: diminished and distorted capacity to process information and draw logical conclusions, hallucinations, delusions, incoherence or marked loosening of associations, catatonic or disorganized behavior, and aggression or violence. Antipsychotic drugs lessen these symptoms regardless of the underlying cause or causes. These agents are prescribed for the treatment of mania, some movement disorders, and various types of nonspecific agitated behaviors but are most frequently employed in the therapy of schizophrenia. Schizophrenia is the term for a group of disorders marked by chronicity, impaired behavioral function, and disturbances of thinking and affect. The disorder has a prevalence of about 1% in the U. S. population, emerging most commonly during late adolescence or early adulthood. Antipsychotic drugs have been used clinically for 50 years, and the first agents introduced, such as chlorpromazine, revolutionized the practice of psychiatry. Many newer agents have since been developed, reflecting significant degrees of success in enhancing potency and diminishing undesirable side effects. The terms antipsychotics and neuroleptics have been applied interchangeably to these drugs, but the latter term refers more appropriately to the older agents, whose extrapyramidal side effects (parkinsonism, dyskinesias, akathisia) are more prominent.