Psychopharmacology is the study of substances that influence mental states. Such agents induce changes in mood, sensation, thinking, or behavior, and may be derived from plants or other natural sources or chemically synthesized in a laboratory. Psychopharmacology encompasses medications used in the treatment of such conditions as depression, anxiety, and psychosis. It also includes agents that relieve acute and chronic pain, and others that curb insomnia and facilitate sleep.
