Psychiatry, a branch of medicine that deals with the causes, diagnosis, and treatment of mental illness. Psychiatrists are doctors of medicine who specialize in psychiatry. Psychiatry is also a branch of psychology, because mental illness affects personality and relationships between persons.
Recognition of the importance of psychiatry came later than that of other medical fields. However, such recognition increased rapidly in the 20th century, largely as a result of new techniques for the understanding of human behavior. An important advance was the realization that most persons with mental disturbance can be helped by proper treatment. In the past, psychiatry had been mainly concerned with classifying mental illness and with custody of the patients.
Another stimulus to psychiatric research and treatment was the growing realization of the important part played by mental illness in such social problems as crime, delinquency, alcoholism, and drug addiction.
