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Oligophrenia
Medical expert of the article
Last reviewed: 12.07.2025
A group of mental and psychological development disorders leading to syndromic limitations of intellectual abilities is called oligophrenia or feeblemindedness in clinical psychiatry.
For this disease, WHO uses the term "mental retardation", and the pathology has the ICD 10 code F70-F79. In the next edition of the International Classification of Diseases, oligophrenia may receive the definition used by foreign psychiatrists - intellectual developmental disorder or intellectual disability.
Causes of oligophrenia
Oligophrenia is a pathology that is congenital or acquired in early childhood. Experts associate the disease with disorders of a genetic, organic and metabolic nature. The key causes of oligophrenia can be divided into prenatal (embryonic), perinatal (from 28 to 40 weeks of pregnancy) and postnatal (postnatal).
Prenatal disorders can be caused by infections acquired from the mother (rubella virus, treponema, toxoplasma, herpes virus, cytomegalovirus, listeria); teratogenic effects on the embryo of alcohol, drugs, some medications; intoxication (phenols, pesticides, lead) or increased radiation levels. Thus, rubeola oligophrenia is a consequence of the fact that the pregnant woman suffered from measles rubella in the first half of gestation, and the embryo was infected from the mother through blood.
Oligophrenia or feeblemindedness are caused by abnormalities in the development of the brain, such as: insufficient brain size (microcephaly), complete or partial absence of the cerebral hemispheres (hydranencephaly), underdevelopment of the convolutions of the brain (lissencephaly), underdevelopment of the cerebellum (pontocerebral hypoplasia), various forms of maxillofacial dysostosis (skull defects). For example, with intrauterine disorders of the pituitary gland formation in a male fetus, the secretion of the gonadotropic hormone luteotropin (luteinizing hormone, LH), which ensures the production of testosterone and the formation of secondary male sexual characteristics, is disrupted. As a result, hypogonadotropic hypogonadism or LH-linked oligophrenia develops. The same picture is observed with damage to the 15th gene, which leads to the birth of a child with Prader-Willi syndrome. This syndrome is characterized not only by hypofunction of the sex glands, but also by mental retardation (a mild form of oligophrenia).
Often the pathogenesis of mental and psychological development disorders is rooted in metabolic disorders (glucosylceramide lipidosis, sucrosuria, latostellosis) or enzyme production (phenylketonuria).
Congenital oligophrenia is practically inevitable in the presence of such a genetic factor as the restructuring of chromosomes, leading to such syndromes of mental retardation as Patau, Edwards, Turner, Cornelia de Lange syndromes, etc., which give impetus to the development of pathology at the stage of embryogenesis.
In most cases, hereditary mental retardation is also genetically determined, and one of the most common endogenous causes of mental retardation is a defect of the 21st X chromosome - Down syndrome. Due to damage to some genes, degeneration of the hypothalamic nuclei may occur, and then Lawrence-Moon-Bardet-Biedl syndrome appears - a type of hereditary mental retardation, often observed in close relatives.
Postpartum oligophrenia in children can be a consequence of intrauterine chronic oxygen deficiency and asphyxia during childbirth, head trauma during childbirth, as well as the destruction of red blood cells - hemolytic disease of the newborn, which occurs due to Rh conflict during pregnancy and leads to serious dysfunction of the cortex and subcortical neural nodes of the brain.
From birth through the first three years of life, causes of mental retardation include infectious lesions of the brain (bacterial meningitis, encephalitis) and traumatic injuries, as well as acute nutritional deficiencies due to chronic malnutrition of the infant.
According to psychiatrists, in 35-40% of cases the pathogenesis of oligophrenia, including congenital, remains unclear. And in such a situation the formulation of the diagnosis of mental retardation may look like undifferentiated oligophrenia.
The diagnosis of familial oligophrenia is made when the doctor is convinced that one or another form of mental retardation and some other characteristic signs are observed in family members, in particular, in siblings. In this case, as a rule, the presence or absence of obvious damage to brain structures is not taken into account, since in clinical practice the study of morphological cerebral anomalies is not carried out in all cases.
Symptoms of oligophrenia
Generally recognized clinical symptoms of mental retardation, whether congenital or developed over time, include:
- delay in the development of speech skills (children begin to speak much later than the accepted norm and speak poorly - with a large number of pronunciation defects);
- irretention;
- limited and concrete thinking;
- difficulty in learning norms of behavior;
- weakened motor skills;
- movement disorders (paresis, partial dyskinesia);
- significant delay in mastering or inability to perform self-care activities (eating, washing, dressing, etc.);
- lack of cognitive interests;
- inadequacy or limited emotional reactions;
- lack of behavioral boundaries and inability to adapt behavior.
Experts note that in early childhood, the first signs of mental retardation, in particular, a minor degree of debility or imbecility, are rarely obvious and can clearly appear only after 4-5 years. True, all patients with Down syndrome have an anomaly of facial features; for Turner syndrome, which affects girls, the characteristic external signs are short stature and short fingers, a wide fold of skin in the neck area, an expanded chest, etc. And with LG-linked mental retardation and Prader-Willi syndrome, by the age of two, an increased appetite, obesity, strabismus, and poor coordination of movements are already evident.
Moreover, even when the fact of poor academic performance, inhibition and inadequacy is obvious, a thorough professional assessment of the children’s mental abilities is necessary in order to distinguish a mild form of debility from emotional and behavioral (mental) disorders.
It is also necessary to take into account that mental retardation in children is caused by a large number of reasons (including pronounced congenital syndromes), and the symptoms of oligophrenia are manifested not only in a decrease in cognitive abilities, but also in other mental and somatic anomalies. Dysfunction of the brain due to a violation of the synthesis of tissue plasminogen activator neuroserpin is manifested by such symptoms as epilepsy and oligophrenia. And patients with idiocy are disconnected from the surrounding reality, and nothing attracts their attention, which, as a rule, is completely absent. A common symptom of this pathology is meaningless monotonous head movements or body swaying.
In addition, the lack of ability for conscious behavior due to anomalies of the cerebral cortex and cerebellum with a pronounced degree of debility and imbecility leads to emotional-volitional disorders. This manifests itself either as hypodynamic oligophrenia (with inhibition of all actions and apathy), or as hyperdynamic oligophrenia, in which psychomotor agitation, increased gesticulation, anxiety, aggressiveness, etc. are observed.
The mental changes that occur with oligophrenia are stable and do not progress, so psychosomatic complications are unlikely, and the main difficulty for patients in this category is the lack of opportunity for full adaptation in society.
Forms and degrees of oligophrenia
In domestic psychiatry, three forms of oligophrenia are distinguished: debility (debility), imbecility and idiocy.
And depending on the volume of missing cognitive abilities, three degrees of oligophrenia are distinguished, which are applied regardless of the etiology of the disease.
Mild degree (ICD 10 - F70) - debility: the level of intellectual development (IQ) fluctuates between 50-69. Patients have minimal sensorimotor slowing; at preschool age they can develop communication skills, are able to acquire some knowledge, and at a later age - professional skills.
Moderate degree (F71-F72) – imbecility: there is the ability to understand other people’s speech and formulate short phrases at the age of 5-6 years; attention and memory are significantly limited, thinking is primitive, but reading, writing, counting and self-care skills can be taught.
Severe degree (F73) – idiocy: thinking in this form of oligophrenia is almost completely blocked (IQ below 20), all actions are limited to reflex acts. Such children are inhibited and unteachable (except for some motor development), and require constant care.
Western specialists classify cretinism, which is a syndrome of congenital hypothyroidism - iodine deficiency in the body, as oligophrenia of metabolic etiology. Regardless of the causes of iodine deficiency (endemic goiter or pathologies of the thyroid gland of a pregnant woman, defects in the development of the thyroid gland in an embryo, etc.), a doctor can code this form of mental retardation F70-F79 indicating the etiology - E02 (subclinical hypothyroidism).
Diagnosis of oligophrenia
Today, oligophrenia is diagnosed by collecting a detailed anamnesis (taking into account obstetricians' data on the course of pregnancy and information on diseases of close relatives), general, psychological and psychometric examination of patients. This allows us to assess their somatic condition, establish the presence of not only physical (visually determined) signs of mental retardation, determine the level of mental development and its compliance with average age norms, and also identify behavioral features and mental reactions.
To accurately determine the specific form of oligophrenia, tests may be required (general, biochemical and serological blood tests, blood tests for syphilis and other infections, urine tests). Genetic tests are performed to identify the genetic causes of the disease.
Instrumental diagnostics include an encephalogram, as well as CT or MRI of the brain (to detect local and generalized craniocerebral defects and structural cerebral disorders). See also - diagnostics of mental retardation.
To diagnose "oligophrenia", differential diagnostics are necessary. Despite the presence of some obvious signs of oligophrenic conditions (in the form of characteristic physical defects), many disorders of a neurological nature (paresis, convulsions, trophic and reflex disorders, epileptiform seizures, etc.) are observed in other psychoneurological pathologies. Therefore, it is important not to confuse oligophrenia with such diseases as schizophrenia, epilepsy, Asperger's syndrome, Geller's syndrome, etc.
When distinguishing it from other diseases that produce symptoms of mental deficiency, it is especially important to take into account the fact that oligophrenia does not show progression, manifests itself from early childhood and in most cases is accompanied by somatic symptoms - lesions of the musculoskeletal system, cardiovascular system, respiratory organs, vision and hearing.
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Treatment of oligophrenia
If the cause of mental retardation is hypothyroidism, Rhesus conflict, phenylketonuria, etiological treatment of oligophrenia is possible: with the help of hormonal drugs, blood transfusion to the infant, a special protein-free diet. Toxoplasmosis can be treated with sulfonamides and Chloridine. But in most cases, alas, etiological treatment does not exist.
Although there are no specific medications for the treatment of oligophrenia, symptomatic therapy is used for patients with limited mental abilities. That is, medications can be prescribed to reduce the intensity of psychotic disorders - neuroleptics, as well as mood stabilizing drugs (helping to correct behavior).
Thus, for general calming, reducing anxiety, stopping seizures and improving sleep, psychotropic tranquilizers are used in psychiatric practice: Diazepam (Seduxen, Valium, Relanium), Phenazepam, Lorazepam (Lorafen), Periciazine (Neuleptil), Chlordiazepoxide (Elenium), Chlorprothixene (Truxal), etc. However, in addition to the possible development of dependence on these drugs, the negative consequences of their use are expressed in muscle weakness, increased drowsiness, impaired coordination of movements and speech, decreased visual acuity. In addition, prolonged use of all of the listed drugs can worsen attention and memory - up to the development of anterograde amnesia.
To stimulate the central nervous system and mental activity, Piracetam (Nootropil), Mesocarb (Sidnocarb), Methylphenidate hydrochloride (Relatin, Meridil, Centedrin) are used. For the same purpose, vitamins B1, B12, B15 are prescribed.
The purpose of Glutamic acid is due to the fact that it is converted in the body into a neurotransmitter - gamma-aminobutyric acid, which helps the brain function in cases of mental retardation.
Folk treatment, for example, with brewer's yeast, is powerless in case of congenital and hereditary mental retardation. The proposed herbal treatment includes regular use of a soothing decoction or tincture of valerian roots in case of hyperdynamic mental retardation. Also worthy of attention among medicinal plants are ginkgo biloba and an adaptogen - ginseng root. Ginseng contains ginsenosides (panaxizides) - steroid glycosides and triterpene saponins that simulate the synthesis of nucleic acids, metabolism and enzyme production, and also activate the pituitary gland and the entire central nervous system. Homeopathy offers a ginseng-based drug - Ginsenoside (Ginsenoside).
One of the main roles in the correction of intellectual disabilities is given to cognitive-behavioral therapy, that is, therapeutic and correctional pedagogy. For the education and upbringing of children with oligophrenia - in specialized schools and boarding schools - specially developed methods are used that allow children to adapt to society.
And rehabilitation of patients with oligophrenia, especially with genetically determined forms of mental pathology, consists not so much in their treatment as in training (according to the peculiarities of cognitive abilities) and instilling elementary everyday and, if possible, simple work skills. Experts say that mild degrees of oligophrenia in children can be corrected, and, despite the disability, such patients can do simple work and take care of themselves. In moderate and severe forms of imbecility and in all degrees of idiocy, the prognosis is complete disability and, often, a long stay in specialized medical institutions and nursing homes.
Prevention of oligophrenia
According to statistics, a quarter of mental retardation is associated with chromosomal abnormalities, so prevention is only possible for non-congenital pathologies.
During the period of preparation for the planned pregnancy, it is necessary to undergo a full examination for infections, thyroid gland condition, and hormone levels. It is necessary to get rid of all inflammation centers and treat existing chronic diseases. Some types of mental retardation can be prevented with the help of genetic counseling of future parents - to identify disorders that are potentially dangerous for the normal development of the embryo and fetus.
During pregnancy, women should be registered with an obstetrician-gynecologist and visit their doctor regularly, take the necessary tests on time and undergo ultrasound. Talking about a healthy lifestyle, rational nutrition and giving up all bad habits during pregnancy planning and during childbearing should acquire a specific meaning and lead to practical actions.
Experts from the American National Institute of Mental Health (NIMH) claim that another important preventive measure is the early detection of certain metabolic processes that lead to mental retardation. For example, if congenital hypothyroidism, which affects one newborn out of 4,000 babies born in the United States, is detected during the first month of life, it can prevent the development of mental retardation. If not detected and treated before the age of three months, then 20% of babies with thyroid hormone deficiency will be mentally retarded. And a delay of up to six months will turn 50% of babies into morons.
According to the U.S. Department of Education, in 2014, about 11% of school-age children were enrolled in classes for students with various forms of mental retardation.