The guide covers the theory of modern psychiatry and all its clinical aspects - from general problems of psychiatric diagnosis, classification issues and modern methodological approaches to the study of psychoses to the description of the clinic, course, prognosis and treatment of mental illness. An important feature of the manual is the coverage of the etiology and pathogenesis of psychoses from the standpoint of modern biological psychiatry and the achievements of related sciences (genetics, immunology, peyromorphology, etc.). Particular attention is paid to the age-related aspect of mental disorders, in particular to issues of gerontopsychiatry. From private psychiatry, volume 1 describes schizophrenia, manic-depressive psychosis, involuntary psychoses.