Oligophrenia (insanity), like psychopathy, is an anomaly of personality development. It is characterized by general mental underdevelopment, the predominance of intellectual deficiency due to hereditary or congenital inferiority of the brain or its defeat in the early (up to three years) stages of ontogenesis. “Oligophrenia” is a clinical concept, it is already a concept of mental retardation, recommended by WHO to designate intellectual deficiency resulting from infectious progressive neuropsychiatric diseases that started early and led to an oligophrenic defect, as well as mental retardation of constitutional, somatogenic, cerebral origin .
The prevalence rates of oligophrenia range from 0.2 to 0.89% (V.V. Kovalev, 1979). In the structure of oligophrenia, idiocy is 4-5%, imbecility is 18-19% and moronity is 76-78% (L. A. Bulakhova, 1981).
In recent years, there has been a slight increase in the incidence of mental retardation, which can be explained by a more accurate account of oligophrenia, the development of medical resuscitation services in micro-pediatrics (a decrease in the mortality of children with genetic inferiority, malformations, defects of the central nervous system, the consequences of severe asphyxia, craniocerebral injuries and cerebral infections).
Etiology of oligophrenia
The etiology of oligophrenia is represented mainly by biological (endogenous and hereditary and exogenous) factors, which, acting at various stages of ontogenesis, lead to gene or chromosomal mutations or through the mother’s body have a damaging effect on the laying of organs and tissues and their subsequent development. Oligophrenia of a known etiology is classified as differentiated forms, unclear – as undifferentiated. The use of methods of cytogenetics, immunology, molecular, biochemical and population genetics expanded the understanding of the etiology of oligophrenia and significantly reduced the group of undifferentiated forms. Abnormal chromosome complexes, enzymatic deficiency found in hereditary forms of the disease.
A large role in the etiology of oligophrenia is played by influenza, rubella, infectious hepatitis, toxoplasmosis, listeriosis, syphilis, transferred during pregnancy. The action of the infectious factor at the stage of embryogenesis often leads to death of the embryo or to dysgenesis (underdevelopment of the brain, anencephaly), at the stage of fetogenesis – to organic damage to the already formed parts of the brain, impaired development of the capillary system of the brain, hypoxia, hydrocephalus. Bacterial factors often affect the fetus, which causes inflammation of the brain tissue and membranes of the brain, as with toxoplasmosis.
Among the etiological factors also include intoxication with drugs (sulfonamides, antibiotics, barbituric acid preparations, antipsychotics), antipyretics, and alcohol. Barbituuric acid preparations accumulate in placental blood and cause fetal poisoning, antipsychotics reduce pressure, which leads to hypoxia, sulfa drugs and antibiotics have teratogenic effects.
Various physical effects are also dangerous: ionizing radiation, high-frequency currents, ultrasound. The removal of women from work with chemical and physical hazards from the first weeks of pregnancy is a necessary condition for the prevention of antenatal pathology. In the genesis of congenital dementia, fetal hypoxia, asphyxia during childbirth and birth trauma are of no small importance. Maternal cardiovascular diseases, vitamin deficiency, hypovitaminosis, toxicosis of pregnancy, pathological pregnancy, diseases of the endocrine system, immunological incompatibility of the blood of the mother and the fetus contribute to this. In the postnatal period, the most common causes of oligophrenia are central nervous system infections and common infectious diseases, the following ” chain ”, less often – brain injuries, severe intoxication, burn disease.
In some cases, adverse environmental influences act as factors that contribute to the identification of hereditary pathology or aggravate its course. The reasons for the development of oligophrenia of multifactorial origin are both environmental factors and genetic factors (P.V. Efroimson, M. G. Blumina, 1978).
Thus, the relationship between heredity and the environment in the origin of oligophrenia is very complex and it is not always possible to single out the leading factor.