Until recently, psychiatrists were mainly engaged in the study and description of unusual forms of behavior, various extravagant ones that do not fit into generally accepted ideas about the norm of mental activity characteristics. Studying mental illnesses, analyzing various signs of the onset of the disease, especially with a slow, gradual increase in its manifestations, psychiatrists gave detailed descriptions of both extreme variants of the norm and various mildly pronounced painful changes in mental activity and behavior of people.
For a long time, only the psyche of a healthy person remained the subject of research by sociologists. Currently, it has become quite obvious that the boundaries between norm and deviation are not rigid, discrete, that there are actually many such varieties of behaviors or mental states where it is extremely difficult to unambiguously determine their relationship to norm or pathology, and under certain circumstances, even impossible. "The study of such conditions is possible only with the integrated use of research methods inherent in both sociology and psychiatry" (Sociology of Development. Edited by G.S. Antipin, M., 2000, p. 34).
The exceptional complexity and insufficient elaboration of a number of important, including basic, concepts of psychological science, the lack of strict definitions of the content of these concepts cause a great variety in the designation of various deviations in the content and forms of mental activity. There are significant differences in the set of terms related to conditions located on the border between norm and pathology. In publications on this topic, the concept of "mental abnormalities" is quite common. In some cases, this concept includes only those mental changes that are the result of a violation of personality formation, its abnormal development (psychopathy and accentuation). In another context, mental abnormalities are understood as "all disorders of mental activity that do not reach the psychotic and do not exclude sanity, i.e. the ability to be aware of their actions and direct them, but are accompanied by personal changes that can lead to deviant behavior." This broader interpretation of the term "mental abnormalities" includes, in addition to psychopathies, personality changes in alcoholism, oligophrenia in the degree of debility, other types of intellectual disability, residual effects of traumatic brain injuries, etc.