Sexology is an interdisciplinary science, uniting a number of branches of knowledge the main feature – the study of human sexuality in all its aspects: biological; psychological, social, moral and ethical, legal, pedagogical, ethnographic, anthropological, hygienic, religious and medical. Therefore, medical sexology (sexopathology) is an integral part of sexology as a science and at the same time a clinical discipline that studies the causes of sexual health disorders, methods of prevention, diagnosis and treatment of sexual disorders.

Sexology stood out from a number of other sciences and became independent only in the 20th century, when the need for systematic knowledge of human sexual behavior increased. However, interest in gender issues has always existed. It is enough to refer to the ancient treatises on sexual practices that have come down to us from time immemorial: “The Art of the Bedroom” (China), “Kama Sutra” and “Ananga Rank” (India), “The Art of Love” (Ancient Greece), etc. In the most ancient mythological, and later in philosophical doctrines, certain information was contained about the nature of sexual differences, the anatomy and physiology of the genital organs, erotic caress and positions of sexual intercourse, conception, pregnancy and childbirth. However, ancient erotology, that is, the theory and practice of the art of love, had a strong patina of mysticism and was not intended to investigate sexuality in depth. Only with the development of a whole complex of biomedical and socio-psychological sciences, after overcoming the resistance of the church and sexuality bigotry among the majority of the population, the prerequisites for a comprehensive and objective assessment of the phenomenon of human sexuality arose. A systematic study of sexuality was first initiated by doctors, and, for a long time, the scope of their research was limited to pathological forms of sexual behavior, and the normal manifestations of human sexuality were left without proper attention.

Among the founders of modern sexology, mention should be made of Professor of Psychiatry at the University of Vienna, Richard von Kraft-Ebing (1840-1902). His work “Sexual psychopathy”, published in 1886, served as the basis for the development of medical sexology. The Austrian doctor, the founder of psychoanalysis Sigmund Freud (1856 – 1939) was the first to open to wide circles of the public the role of sexuality in a person’s life. He came to the conclusion that the cause of neurosis are unconscious conflicts of a sexual nature. Exploring the psychosexual development of a child, Freud showed the effect of his disorders on the mental health and sexuality of an adult. He developed his theory of infant sexuality in the book Three Essays on the Theory of Sexuality, which was published in 1905. In many ways, precisely because of the works of Freud, sexuality began to be seriously studied in medicine and psychology.

German dermatovenerologist Ivan Bloch (1872 – 1922) studied the history of prostitution and “unusual” sexual behavior, and in his book “The Sexual Life of Our Time and Its Relationship to Modern Culture”, published in 1909, for the first time presented in a systematic way the whole complex of existing that time period of sexological knowledge. The German psychiatrist Magnus Hirschfeld (1868 – 1935) investigated sexological problems in social, historical and medical aspects. He attached primary importance to the solution of ethical and legal problems, sought to resolve issues of prostitution and birth control. In 1918, in Berlin, Hirschfeld founded and headed the world’s first sexological institute. The English publicist, publisher, and physician Henry Havelock Ellis (1859–1939) spent several decades studying all the information available at the time about human sexual behavior in the Western world and other cultures. As a result, from 1886 to 1928, he published seven volumes of “Studies on the psychology of sex.” They recognized the multivariate of sexual behavior and inclinations shown by people, as well as the dependence of sexual morality on cultural and social factors.

The works of Ellis undoubtedly played a role in the gradual liberalization of the sexual attitudes prevailing in the Victorian era (see Victorianism). An important role in the development of sexology was made by the Swiss neuropathologist, psychiatrist and entomologist August Forel (1848-1931), who in 1906 published the work “Sexual Issue”, as well as the German psychiatrist Albert Moll (1862-1939), who summarized his views on the sexual development of children and sex education in the work “The Sexual Life of a Child”, published in 1908. Peru, the Dutch gynecologist Theodore Van de Velde (1873 – 1937) owns the book “The Perfect Marriage”, which was first published in 1926, was extremely popular, and by 1967 it had 77 publications. Van de Velde proposed his concept of harmonious marriage, which takes into account the variety of factors contributing to the stability of marriage. Among them, he assigned the most important role to the increase in sexual satisfaction of spouses.

The American biologist Alfred Kinsey (1894-1956) made a significant contribution to the development of modern sexology. He conducted a large-scale study of the sexual behavior of people for the first time (more than 16,000 people were subjected to a detailed survey). The result of this study was the works “Sexual behavior of a man” and “Sexual behavior of a woman”, published respectively in 1948 and 1953. Kinsey and his staff convincingly proved the existence of a huge range of individual differences in the manifestations of human sexuality. American gynecologist William Masters (born in 1915), together with his collaborator Virginia Johnson, were the first in the laboratory to study in detail the normal physiological reactions of a man and a woman during sexual intercourse. A detailed account of their work is presented in the book Sexual Responses in Man, published in 1966. Masters and Johnson developed an original approach to the treatment of sexual dysfunction, which was described in his book Sexual Inadequacy in Man. In 1970, the publication of this publication marked the birth of sex therapy. Recent studies conducted in neurophysiology, genetics, embryology, evolutionary biology, endocrinology, gynecology, psychology and other scientific disciplines, have significantly enriched and expanded knowledge in the field of differentiation and relationships between different sexes, various aspects of human sexuality.

Sexopathology (medical sexology) is a field of clinical medicine that studies the causes of sexual dysfunction, diagnosis, clinic, course, prognosis of disorders of the sexual sphere, as well as their treatment and prevention. It is based on an interdisciplinary (systemic) approach and in identifying patterns of development of sexual pathology, its diagnosis and treatment relies on psychiatry, clinical psychology, psychotherapy, urology, andrology, gynecology, endocrinology, neuropathology, angiology.

G.S. Vasilchenko (1990) identified three main stages of the formation of sexopathology. At the first, naively mechanistic, stage (late XIX – early XX centuries) all sexual disorders were associated with diseases of the male or female genital organs. The second, encyclopedic, stage in the development of sexopathology (beginning – mid-XX century) marked the transition to multidisciplinary methodological positions. Its result was the overcoming of one-sided views on the nature of sexual pathology and the recognition of the multifactorial nature of sexual disorders that can occur in various forms of mental, neurological, urological, gynecological, endocrine pathology. The transition to the third stage is connected with the fundamental works of domestic researchers (V. A. Geodakyan, IS Kon, and others). On the basis of the general theory of functional systems P. K. Anokhin and the concept of the stages and components of the copulative cycle G.S. Vasilchenko developed the first interdisciplinary model of sexopathology, opening its systemic stage. Developing the system concept, V.V. Krishtal identified four aspects of human sexuality — social, psychological, socio-psychological, and medical-biological — and their corresponding directions in sexology and sexopathology. The system approach allows to reveal the role of numerous negative social, psychological and biological factors in the genesis of sexual disorders and on this basis to develop the most adequate therapeutic and preventive measures.

Sexopathology, being a single discipline, is divided into general and particular. General sexopathology studies the basic laws of the relationship and differentiation of the sexes, the anatomical and physiological characteristics of the sexual sphere and sexuality, issues of the sexual norm and pathology, the forms of realization of human sexual needs, epidemiology and phenomenology of sexual disorders, causes and conditions for the development of sexual disharmony. Private sexopathology studies specific forms of sexual dysfunctions, their etiopathogenesis, clinic, develops methods for diagnosing, preventing and treating one or another disease. An important postulate of modern scientific sexopathology is the principle of pairing, which forms the basis of the concept of partnership and is taken into account in the diagnosis and treatment of sexual disorders.