This is an analysis of the statistical data on two important public health problems. Although systematic annual morbidity statistics for mental disorders are nonexistent, extensive data exist for the United States on patterns of use of mental hospitals and other types of psychiatric facilities. The chapters dealing with mental disorders examine these data in considerable detail. The section on suicide provides mortality rates from this cause derived from data on all deaths occurring in the United States, and discusses demographic variables as well as various sociological and psychological theories about suicide. The authors are affiliated with the National Institute of Mental Health.