Epidemiology of schizophrenia. Epidemiology and etiology

According to epidemiological studies, there are three main risk factors for schizophrenia:

— exposure to harmful factors in the prenatal period or early childhood;

Genetic factors play a role in at least some people with schizophrenia, according to studies of families, twins and adopted children. If we apply strict diagnostic criteria, then schizophrenia is observed in approximately 6.6% of relatives who are related to the patient in the first degree. If both parents suffer from schizophrenia, the risk of the disease in children is 40%. Concordance for schizophrenia in identical twins is 50%, and in fraternal twins it is only 10%. In families with an increased frequency of schizophrenia, there are more cases of other mental disorders of the psychotic and non-psychotic series, including schizoaffective psychosis, schizotypal and schizoid psychopathy.

More and more evidence is accumulating that environmental factors play a role in the development of schizophrenia, which can modulate the effect of genetic factors, and sometimes be the direct cause of the disease. The etiological role of intrauterine and perinatal complications is suggested, such as incompatibility of Rh system antigens, poor maternal nutrition during pregnancy, and influenza in the second trimester.

It has been shown that identical twins discordant for schizophrenia have differences in brain morphology, which further confirms the hypothesis that both genetic and environmental factors play an important role.

Epidemiology of schizophrenia

Studying the prevalence of schizophrenia (even its manifest forms) presents significant difficulties, since the identification of patients is influenced by many factors - representativeness of the sample, differences in diagnostic approaches, accessibility and quality of psychiatric services, as well as features of patient registration. A change in the principles of patient registration in our country in recent years has further complicated the situation in epidemiological studies of schizophrenia, giving sufficient grounds for the assumption that some patients remain outside the attention of psychiatrists. The comparison of data from different years and the results of studies conducted in different countries becomes all the more important.

Soreness. In 1997, WHO data were published, according to which there are 45 million people with schizophrenia in the world. In terms of the entire population of the globe (5.8 billion), this amounts to 0.77%. This is close to the figure given by W. T. Carpenter and R. W. Buchanan (1995). They indicate that in the last decade of the 20th century, the prevalence of schizophrenia was 0.85%, i.e. approximately 1% of the world's population suffers from this disease.

Despite the existing fluctuations in morbidity rates in individual countries, their similarities are noted, including relative stability over the past 50 years (a summary of the relevant data was given by M. E. Vartanyan in 1983 in a manual on psychiatry edited by A. V. Snezhnevsky ). Unfortunately, due to the lack of accurate epidemiological information, it is impossible to compare the prevalence of the pathology in question over a longer period.

The above morbidity rate refers to manifest forms of schizophrenia, and it would increase significantly if “schizophrenia spectrum disorders” were included in this group. For example, according to W. T. Carpenter and R. W. Buchanan (1995), the lifetime prevalence of “schizotypal personality disorders” is determined to be 1-4%, schizoaffective disorders - 0.7%, atypical psychoses and delusional disorders - 0.7%.

The influence of diagnostic approaches and the ability of psychiatric services to identify patients is also reflected in the results of other foreign studies.

According to the generalized data of H. Babigian (1975) and D. Tunis (1980), incidence rates of schizophrenia in the world fluctuate within a fairly wide range - from 1.9 to 10 per 1000 population. American researchers D. A. Regier and J. D. Burke in 1989 indicated the prevalence of schizophrenia in the United States to be 7 per 1000 population (i.e., 0.7%). A more detailed analysis of the prevalence of schizophrenia was given by M. Kato and G. S. Norquist (1989). According to the authors, 50 studies conducted from 1931 to 1938 in different countries made it possible to establish fluctuations in the corresponding indicators from 0.6 to 7.1 (according to the point pre valence indicator) and from 0.9 to 11 (according to the lifetime prevalence indicator ) per 1000 population. The highest rates were found in Canada - I (in the Native American population), and the lowest in Ghana - 0.6. A special study “Epidemiological catchment area”, carried out under the leadership of the US National Institute of Mental Health in 1980-1984, allowed us to establish the lifetime prevalence of schizophrenia in the range of 0.6-1.9 per 1000 population.

Presenting a review of the mental health of Russia in 1986-1995, A. A. Churkin (1997) provides the following data: in 1991, 4.2 patients were registered, in 1992, 1993 and 1994. - 4.1 each and in 1995 - 4 per 1000 population. The latest data on the prevalence of schizophrenia were provided in 1998 by Yu. V. Seika, T. A. Kharkova, T.A. Solokhin and V.G. Rotshtein. They also highlighted the prospects for the development of the situation: according to data for 1996, the prevalence of schizophrenia was 8.3 per 1000 population; by 2001, 8.2 are expected, and by 2011, 8.5 per 1000 population.

Morbidity. Morbidity rates, according to the results of foreign studies (as well as the prevalence of schizophrenia), vary from 0.43 to 0.69, according to one data [Babigian P., 1975], and from 0.3 to 1.2 per 1000 population - according to others [Turns D., 1980]. In different countries of the world they range from 0.11 to 0.7 [Carpenter W. T., Buchnan R. W., 1995].

According to the Institute of Psychiatry of the USSR Academy of Medical Sciences (as of 1979), the overall incidence rate of schizophrenia was 1.9 per 1000 population.

Morbidity and incidence of schizophrenia in different age groups. According to L.M. Shmaonova and Yu.I. Liberman (1979), the highest incidence of schizophrenia occurs at the age of 20-29 years and decreases as it increases. Similar indicators are given by D. A. Regier and J. D. Burke (1989): the highest incidence of schizophrenia is observed in the age group 25 years-44 years (11 per 1000 population) and slightly lower (8 patients per 1000 population) in the age group 18 years-24 years. Outside these age periods, the number of patients with schizophrenia decreases. So, according to W. H. Green (1989), the prevalence of schizophrenia in children under 12 years of age is 0.17-0.4. A high incidence rate of schizophrenia (1.66), obtained from a comprehensive examination of children under 14 years of age, is cited by G.V. Kozlovskaya (1980).

Schizophrenia in men and women. The risk of developing schizophrenia in men and women and, accordingly, morbidity rates, according to most authors, do not differ [Zharikov N. M., 1983; Karno M., Norquist G. S., 1989]. This is consistent with the disease prevalence rates given by Yu. V. Seiku et al. (1998): 7.7 per 1000 in men and 8.2 in women; by 2011, according to their calculations, the ratio should remain 8.2 and 8.8, respectively.

Various forms of schizophrenia. According to the results of studies by L. M. Shmaonova and Yu. I. Liberman (1979), the prevalence of malignant continuous schizophrenia is 0.49, paroxysmal-progressive - 3.3, sluggish - 2.87, undifferentiated by form - 0.06 per 1000 population.

The incidence of continuous schizophrenia (both malignant and low-progressive) in men compared to women is higher - 1.4 and 0.03, respectively, for malignant forms and 0.78 and 0.44 for low-progressive forms. Paroxysmal-progressive and recurrent forms, on the contrary, are more often observed in women - 0.26 and 0.16 in the first case and 0.34 and 0.2 in the second.

The unclear boundaries of some forms of schizophrenia are reflected in their prevalence rates. Thus, the morbidity rate of sluggish schizophrenia, according to L. A. Gorbatsevich (1990), is equal to 1.44 per 1000 population, and according to N. M. Zharikov, Yu. I. Liberman, V. G. Rotshtein, obtained in 1973 g., - 4.17.

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116. Epidemiology of schizophrenia.

Schizophrenia- a chronic mental illness, which is based on a hereditary predisposition, beginning mainly at a young age, characterized by a variety of clinical symptoms with productive and negative syndromes, a tendency towards progressive progression and often leading to persistent impairment of social adaptation and ability to work. Available statistical data and the results of epidemiological studies allow us to conclude that its distribution rates are similar in all countries and amount to 1–2% of the total population. The initial assumption that schizophrenia is less common in developing countries has not been confirmed. The results of studies specifically conducted in developing countries revealed a similar number of patients with schizophrenia (1 new case per 1000 people annually) with the number of patients with schizophrenia in European countries. There is only a difference in the representativeness of certain types of clinical manifestations of the disease. Thus, among patients living in developing countries, acute conditions with confusion, catatonic, etc. are more common.

The average age of onset of the disease is 20 - 25 years for men and 25 - 35 years for women. There is a family predisposition to schizophrenia. If both parents are sick, then the child’s risk of illness is 40-50%, if one of them is sick - 5%. First-degree relatives of people with schizophrenia are diagnosed with the disease much more often than third-degree relatives (cousins), who are almost as likely to have schizophrenia as the general population.

117. Modern ideas about the etiology and pathogenesis of schizophrenia.

The etiology and pathogenesis of schizophrenia became the subject of special study soon after the disease was identified as a separate nosological unit. E. Kraepelin believed that schizophrenia occurs as a result of toxicosis and, in particular, dysfunction of the gonads. The idea of ​​the toxic nature of schizophrenia was developed in other subsequent studies. Thus, the occurrence of schizophrenia was associated with a violation of protein metabolism and the accumulation of nitrogenous breakdown products in the body of patients. In relatively recent times, the idea of ​​the toxic nature of schizophrenia was presented by an attempt to obtain a special substance, thoraxein, in the blood serum of patients with this disease. However, the idea that there is a specific substance in patients with schizophrenia has not received further confirmation. Toxic products are present in the blood serum of patients with schizophrenia, but they are not particularly specific, characteristic only of patients with schizophrenia.

In recent years, certain advances have been made in the biochemical study of schizophrenia, making it possible to formulate biochemical hypotheses for its development.

The most representative are the so-called catecholamine and indole hypotheses. The first are based on the assumption of the role of dysfunction of norepinephrine and dopamine in the mechanisms of disruption of neurobiological processes in the brain of patients with schizophrenia. Proponents of the indole hypothesis believe that since serotonin and its metabolism, as well as other indole derivatives, play an important role in the mechanisms of mental activity, dysfunction of these substances or components of their metabolism can lead to the occurrence of schizophrenia. In essence, the idea of ​​a connection between the schizophrenic process and dysfunction of enzyme systems involved in the metabolism of biogenic amines is also close to the concepts described above.

personal adaptation to life. The impossibility of full adaptation is explained by a special personality defect formed as a result of incorrect interpersonal relationships within the family in early childhood. Such ideas about the nature of schizophrenia have been refuted. It has been shown that the risk of schizophrenia in children who have adapted at an early age to other families is not due to the peculiarities of intrafamily relationships in them, but to hereditary burden.

Definition of schizophrenia. Etiology, pathogenesis, epidemiology

Schizophrenia. Affective disorders.

1. Definition of schizophrenia. Etiology, pathogenesis, epidemiology.

2. Symptomatology of schizophrenia: productive and negative symptoms.

3. Types of course of schizophrenia.

4. Remissions in schizophrenia.

5. Affective disorders.

Schizophrenia (schisis – splitting, phren – soul, mind) – endogenous progressive mental illness, manifested by specific personality changes and a variety of productive symptoms.

According to etiology, schizophrenia refers to endogenous diseases , i.e. occurs against the background of a hereditary predisposition, which is realized under the influence of various physical or mental provoking factors ( stress diathesis theory schizophrenia), age-related crises or spontaneously. External factors also contribute to the development of exacerbations of the disease.

Hereditary predisposition suggests the presence relatives of the patient have a higher risk of developing schizophrenia than in the population. If one parent has schizophrenia, the risk for the child is about 15%, for both – about 50%. If one of the monozygotic twins is sick, then the risk of disease for the second does not exceed 80%, i.e. it is not absolute (the role of exogenous provoking factors).

At the core pathogenesis schizophrenia is due to disturbances in neurotransmitter transmission carried out by dopamine, serotonin, norepinephrine, etc. (this is confirmed by the effectiveness of antipsychotics). The main role is given to dopamine. Activation of dopamine transmission in the mesolimbic pathway is associated with the development of psychotic symptoms, and inhibition of transmission in the mesocortical pathway is associated with the development of negative disorders.

Identified morphological changes in the brains of patients with schizophrenia: mild atrophy of gray matter (especially the frontal lobes and hippocampus) along with an increase in the volume of white matter and ventricles. However, the relationship between morphological changes and the clinic has not yet been established. The diagnosis of schizophrenia is made only clinically without pathological confirmation.

Schizophrenia is progressive disease, i.e. it leads to a steadily increasing disintegration of the psyche. Its pace may vary. This decay leads to the loss of unity between mental processes, the formation specific personality changes , up to schizophrenic dementia (“a car without a driver”, “a book with tangled pages”). Memory and intelligence do not suffer in schizophrenia, but the ability to use them is impaired. Patients with schizophrenia behave strangely, are characterized by unusual and unpredictability of emotional reactions and statements (they do not understand the context of the situation, they do not know how to read emotions on faces). These specific features of schizophrenia were first described by Eugene Bleuler (4 “A” - associations, affect, ambivalence, autism), he also proposed this term. That's why schizophrenia is called "Bleuler's disease."

In addition to specific personality changes, schizophrenia manifests itself in a variety of ways. productive symptoms (delusions, hallucinations, depression, mania, catatonia, etc.). These symptoms are less specific because also occur in other diseases.

In schizophrenia, there are no symptoms characteristic of organic brain damage (paroxysms, memory loss, psychoorganic syndrome).

Prevalence schizophrenia is about 1%. This indicator is common to all countries of the world and does not depend on national, cultural, economic and other conditions. About 2/3 of patients are under the supervision of psychiatrists, i.e., if we focus on the accounting population, then the prevalence is about 0.6% of the population.

Age onset of the disease – from 14 to 35 years. Peak incidence is 20-30 years. Schizophrenia rarely appears in childhood (although cases of schizophrenia in the first years of life have been described). After 40 years, the risk of developing the disease decreases sharply.

Men and women get sick equally often, but severe continuous forms of schizophrenia are 4 times more common in men.

In terms of social consequences, schizophrenia is a very serious disease. A significant proportion of people with mental disabilities suffer from schizophrenia.

2. Symptomatology of schizophrenia: productive and negative symptoms.

Clinical manifestations of schizophrenia are divided into two groups.

1. Obligate symptoms . These are mandatory symptoms characteristic of schizophrenia. Their appearance makes the diagnosis certain. They can be presented in whole or in part, appear earlier or later, and have different severity. At its core it is - negative symptoms(manifestations of mental breakdown). Modern drugs have virtually no effect on them. The following groups of obligate symptoms are distinguished ( it is necessary to decipher the meaning of the terms):

· thinking disorders: sperrung, mentism, slippage, fragmentation, verbigeration, symbolic thinking, neologisms, reasoning;

· pathology of emotions: decrease in emotional resonance up to emotional dullness, inadequacy of emotions, paradoxicality of emotions (symptom of “wood and glass”), ambivalence;

· disturbances of volitional activity: hypobulia (decreased energy potential), symptom of drift (subordination to external circumstances), ambitendence;

· autism(separation from reality, withdrawal into the inner world).

2. Optional symptoms . These symptoms are additional, i.e. they are less specific for schizophrenia and may occur in other diseases. This - productive symptoms(delusions, hallucinations). However, some of them are considered more or less typical of schizophrenia. Due to the fact that it is easier to identify productive symptoms than negative ones, today productive symptoms (rank I symptoms) are used as the main diagnostic criteria for schizophrenia. These include:

· taking away thoughts, putting in thoughts, sounding thoughts;

· ridiculous crazy ideas (communication with aliens, weather control).

To make a diagnosis, the presence of one of the four listed symptoms for at least 30 days is sufficient.

The remaining productive symptoms (other types of hallucinations, persecutory delusions, catatonia, depression, mania) are of auxiliary value for diagnosis.

Schizophrenia: Epidemiology.

Introduction.
According to WHO, schizophrenia is one of the ten leading causes of disability and is called “the worst disease that affects humans.”

Despite intensive research over the last century, the etiology and pathophysiology remain relatively unclear. But our incomplete understanding of the nature of schizophrenia cannot be explained by a lack of scientific evidence. Currently, there are several hundred thousand publications on schizophrenia, which provide us with thousands of different data.

Below we will try to summarize the available data in order to present the current understanding of this disease process.

Epidemiological data.
Over the past years, schizophrenia has remained the most mysterious and, at the same time, the most widely diagnosed psychiatric disease, regardless of the population and diagnostic systems used. The prevalence of schizophrenia in the world is estimated at 0.8-1%, the incidence is 15 per 100,000 population. The widespread prevalence of schizophrenia throughout the world suggests a genetic basis for the disease, which contradicts the view that it is a "new disease", and most researchers believe that schizophrenia existed long before its first detailed descriptions in the early 19th century.

This is interesting:
Why has the prevalence of schizophrenia remained relatively stable around the world, despite its obvious evolutionary disadvantages such as reduced reproduction and increased mortality? It has been suggested that genes implicated in the development of schizophrenia may be important for human adaptive evolution and therefore represent an evolutionary advantage for unaffected relatives of people with schizophrenia.

Literature

1. Tandon, R., Keshavan M., Nasrallah H., 2008. Schizophrenia, “Just the Facts”What we know in 2008. Part 1: Overview. Schizophr. Res. 100, 4-19 2.
2. Psychiatry: a reference book for a practitioner / Ed. A. G. Hoffman. - M.: MEDpress-inform, 2010. 3.
3. Tandon, R., Keshavan M., Nasrallah H., 2008. Schizophrenia, “Just the Facts”What we know in 2008. 2. Epidemiology and etiology. Schizophr. Res.102, 1-18 4.

Schizophrenia. Affective disorders.

1. Definition of schizophrenia. Etiology, pathogenesis, epidemiology.

2. Symptomatology of schizophrenia: productive and negative symptoms.

3. Types of course of schizophrenia.

4. Remissions in schizophrenia.

5. Affective disorders.

Schizophrenia (schisis – splitting, phren – soul, mind) – endogenous progressive mental illness, manifested by specific personality changes and a variety of productive symptoms.

According to etiology, schizophrenia refers to endogenous diseases , i.e. occurs against the background of a hereditary predisposition, which is realized under the influence of various physical or mental provoking factors ( stress diathesis theory schizophrenia), age-related crises or spontaneously. External factors also contribute to the development of exacerbations of the disease.

Hereditary predisposition suggests the presence relatives of the patient have a higher risk of developing schizophrenia than in the population. If one parent has schizophrenia, the risk for the child is about 15%, for both – about 50%. If one of the monozygotic twins is sick, then the risk of disease for the second does not exceed 80%, i.e. it is not absolute (the role of exogenous provoking factors).

At the core pathogenesis schizophrenia is due to disturbances in neurotransmitter transmission carried out by dopamine, serotonin, norepinephrine, etc. (this is confirmed by the effectiveness of antipsychotics). The main role is given to dopamine. Activation of dopamine transmission in the mesolimbic pathway is associated with the development of psychotic symptoms, and inhibition of transmission in the mesocortical pathway is associated with the development of negative disorders.

Identified morphological changes in the brains of patients with schizophrenia: mild atrophy of gray matter (especially the frontal lobes and hippocampus) along with an increase in the volume of white matter and ventricles. However, the relationship between morphological changes and the clinic has not yet been established. The diagnosis of schizophrenia is made only clinically without pathological confirmation.

Schizophrenia is progressive disease, i.e. it leads to a steadily increasing disintegration of the psyche. Its pace may vary. This decay leads to the loss of unity between mental processes, the formation specific personality changes , up to schizophrenic dementia (“a car without a driver”, “a book with tangled pages”). Memory and intelligence do not suffer in schizophrenia, but the ability to use them is impaired. Patients with schizophrenia behave strangely, are characterized by unusual and unpredictability of emotional reactions and statements (they do not understand the context of the situation, they do not know how to read emotions on faces). These specific features of schizophrenia were first described by Eugene Bleuler (4 “A” - associations, affect, ambivalence, autism), he also proposed this term. That's why schizophrenia is called "Bleuler's disease."

In addition to specific personality changes, schizophrenia manifests itself in a variety of ways. productive symptoms (delusions, hallucinations, depression, mania, catatonia, etc.). These symptoms are less specific because also occur in other diseases.

In schizophrenia, there are no symptoms characteristic of organic brain damage (paroxysms, memory loss, psychoorganic syndrome).

Prevalence schizophrenia is about 1%. This indicator is common to all countries of the world and does not depend on national, cultural, economic and other conditions. About 2/3 of patients are under the supervision of psychiatrists, i.e., if we focus on the accounting population, then the prevalence is about 0.6% of the population.

Age onset of the disease – from 14 to 35 years. Peak incidence is 20-30 years. Schizophrenia rarely appears in childhood (although cases of schizophrenia in the first years of life have been described). After 40 years, the risk of developing the disease decreases sharply.

Men and women get sick equally often, but severe continuous forms of schizophrenia are 4 times more common in men.

In terms of social consequences, schizophrenia is a very serious disease. A significant proportion of people with mental disabilities suffer from schizophrenia.

2. Symptomatology of schizophrenia: productive and negative symptoms.

Clinical manifestations of schizophrenia are divided into two groups.

1. Obligate symptoms . These are mandatory symptoms characteristic of schizophrenia. Their appearance makes the diagnosis certain. They can be presented in whole or in part, appear earlier or later, and have different severity. At its core it is - negative symptoms(manifestations of mental breakdown). Modern drugs have virtually no effect on them. The following groups of obligate symptoms are distinguished ( it is necessary to decipher the meaning of the terms):

· thinking disorders: sperrung, mentism, slippage, fragmentation, verbigeration, symbolic thinking, neologisms, reasoning;

· pathology of emotions: decrease in emotional resonance up to emotional dullness, inadequacy of emotions, paradoxicality of emotions (symptom of “wood and glass”), ambivalence;

· disturbances of volitional activity: hypobulia (decreased energy potential), symptom of drift (subordination to external circumstances), ambitendence;

· autism(separation from reality, withdrawal into the inner world).

2. Optional symptoms . These symptoms are additional, i.e. they are less specific for schizophrenia and may occur in other diseases. This - productive symptoms(delusions, hallucinations). However, some of them are considered more or less typical of schizophrenia. Due to the fact that it is easier to identify productive symptoms than negative ones, today productive symptoms (rank I symptoms) are used as the main diagnostic criteria for schizophrenia. These include:

· taking away thoughts, putting in thoughts, sounding thoughts;

· delirium influence;

· ridiculous crazy ideas (communication with aliens, weather control).

To make a diagnosis, the presence of one of the four listed symptoms for at least 30 days is sufficient.

The remaining productive symptoms (other types of hallucinations, persecutory delusions, catatonia, depression, mania) are of auxiliary value for diagnosis.

Incidence and prevalence rates depend on diagnostic criteria and the characteristics of the population being examined (diagnostic issues are discussed on pp. 204–208).

The annual incidence appears to be 0.1-0.5 per 1000 population. Thus, according to research, the incidence rate (per 1000 people) at first contact with health services in Camberwell in London is 0.11-0.14 (Wing, Fryers 1976), and in Mannheim - about 0.54 (Hafner, Reimann 1970 ). The incidence varies depending on age: the highest rates are observed among young men and among women aged 35-39 years.

Development risk The lifetime incidence of schizophrenia appears to be between 7.0 and 9.0 per 1000 people (see Jablensky 1986). For example, among the island population, according to cohort studies, rates of 9.0 were recorded (per 1000 people) in the Danish Archipelago (Fremming 1951) and 7.0 in Iceland (Helgason 1964).

Index Prevalence Schizophrenia in European countries probably reaches 2.5-5.3 per 1000 people (see Jablensky 1986). Collaborative studies conducted by the World Health Organization have demonstrated that, when compared, the prevalence of schizophrenia in different countries is approximately the same (Jablensky, Sartorius 1975). The similarity is greatest if symptoms of the first rank according to Schneider are used as diagnostic criteria (see p. 205) (Jablensky et al. 1986).

However, there are exceptions to this general picture of homogeneous indicators. Thus, a high level (11 per 1000 people) of annual incidence (the totality of all - both primary and secondary - cases of the disease registered during the year - Ed.) was reported in the far north of Sweden (Bok 1953). High rates were also observed in northwestern Yugoslavia and western Ireland, among the Catholic population of Canada, and among the Tamils ​​of southern India (see Cooper 1978). In contrast, a low rate (1.1 per 1000 people) was recorded among the Hutterite Anabaptist sect in the United States (Eaton and Weil 1955).

This difference in disease prevalence estimates may be due to several reasons. First, it may reflect discrepancies in diagnostic criteria. Secondly, differences in migration may have an impact. For example, it is likely that people predisposed to schizophrenia are more likely to stay in the remote northern areas of Sweden because they are better able to tolerate extreme isolation; at the same time, other persons, also predisposed to schizophrenia, leave the Hutterite community because they are unable to withstand constant stay in the conditions of a close, closely knit community. A third reason, related to the second, is that disease prevalence rates may reflect differences in case detection techniques. Thus, Eaton and Weil's findings seem to be partly attributable to the peculiarities of their approach, since a study conducted in Canada found no difference between the rates of hospitalization for schizophrenia in Hutterite communities and in other populations (Murphy 1968). The high incidence rate in western Ireland was also not confirmed by further studies (NiNuallain et al. 1987). Finally, it should be noted that differences in disease prevalence are not necessarily explained by any differences in disease duration. Epidemiological studies of demographic and social correlates of schizophrenia are discussed further in the section on etiology.

Among the diagnoses admitted to a psychiatric hospital, schizophrenia makes up about 25% of first-time admissions and always ranks second. Schizophrenics make up more than half of chronic hospitalizations and, on average, stay in hospital longer than those with other psychiatric diagnoses. Recently, a large number of chronic schizophrenics have moved to boarding homes (dormitories, boarding houses), and therefore fundamental changes have occurred: the number of patients with chronic schizophrenia
in psychiatric hospitals is constantly decreasing.
We do not have a reliable number of patients with schizophrenia seeking outpatient care.
Estimates show that about 0.25% of the adult population experiences schizophrenia for the first time each year. About 1% of the population should fear a schizophrenic illness in their lifetime.
Transcultural comparisons provide significant differences in the incidence of the disease. Representative studies in different segments of the population show that
taking into account demographic correction, 10 cases (Inzidens) of schizophrenia per 1000 people. on the west coast of Norway, and half as much (5 or 4.9) in Japan. In Thuringia, this indicator is set at only 3.8 per 1000 people.

– previous | next-

Introduction.
According to WHO, schizophrenia is one of the ten leading causes of disability and is called “the worst disease that affects humans.”

Despite intensive research over the last century, the etiology and pathophysiology remain relatively unclear. But our incomplete understanding of the nature of schizophrenia cannot be explained by a lack of scientific evidence. Currently, there are several hundred thousand publications on schizophrenia, which provide us with thousands of different data.

Below we will try to summarize the available data in order to present the current understanding of this disease process.

Epidemiological data.
Over the past years, schizophrenia has remained the most mysterious and, at the same time, the most widely diagnosed psychiatric disease, regardless of the population and diagnostic systems used. The prevalence of schizophrenia in the world is estimated at 0.8-1%, the incidence is 15 per 100,000 population. The widespread prevalence of schizophrenia throughout the world suggests a genetic basis for the disease, which contradicts the view that it is a "new disease", and most researchers believe that schizophrenia existed long before its first detailed descriptions in the early 19th century.

This is interesting:
Why has the prevalence of schizophrenia remained relatively stable around the world, despite its obvious evolutionary disadvantages such as reduced reproduction and increased mortality? It has been suggested that genes implicated in the development of schizophrenia may be important for human adaptive evolution and therefore represent an evolutionary advantage for unaffected relatives of people with schizophrenia.

Literature

1. Tandon, R., Keshavan M., Nasrallah H., 2008. Schizophrenia, “Just the Facts”What we know in 2008. Part 1: Overview. Schizophr. Res. 100, 4-19 2.
2. Psychiatry: a reference book for a practitioner / Ed. A. G. Hoffman. - M.: MEDpress-inform, 2010. 3.
3. Tandon, R., Keshavan M., Nasrallah H., 2008. Schizophrenia, “Just the Facts”What we know in 2008. 2. Epidemiology and etiology. Schizophr. Res.102, 1-18 4.

Information current as of 09/17/2010

Epidemiology and etiology of schizophrenia

Synonyms: schizophrenic psychosis, “madness of duality”

Definition of schizophrenia:
Schizophrenic psychoses are included in the group of endogenous psychoses (caused by predisposition factors)
Characterized by the presence of various disorders of thinking, perception, emotional sphere, personality (presence of delusions, hallucinations, impaired perception of reality)

Epidemiology of schizophrenia

The prevalence of schizophrenia ranges from 0.5 to 1%, the risk of the disease in the population is about 1%, women and men are equally susceptible to the disease (in Germany there are 800 thousand patients with schizophrenia)

The main age for the development of the disease is the period between adolescence and the 30th year of life; in 80% of cases, the manifestation is registered before the age of 40. Unlike men, women get sick 3-4 years later. Age differences are typical for individual forms:
- hebephrenic form in adolescence
— hallucinatory-paranoid forms of the 4th decade of life
- late schizophrenia after 40 years
- senile schizophrenia after 60 years

High suicide rate among patients with schizophrenia, about 10%; both in acute episodes and in post-psychotic stages of remission

Huge economic and socio-medical significance: medical costs (direct and indirect) - about 10 billion euros per year!

Etiopathogenesis of schizophrenia

Multifactorial causes of schizophrenia:
Model “vulnerability-stress-coping (with the situation)”: disposition (predisposition) and (nonspecific) internal mental, personal and social stress loads lead to decompensation (the occurrence of psychosis) In 75% of cases there are no external triggers The genetic basis of the disease, confirmed by the results of studies of twins, families and adoptions:
- Concordance rates for identical twins are approximately 4 times higher than for fraternal twins, amounting to 50%. The risk of developing the disease clearly increases depending on the degree of close relationship
— genetic disposition is interpreted as a polygenic hereditary predisposition (involvement of 2 or more pairs of genes). Neuregulin and Dysbindin are currently considered to be putative factor genes

Somatic and biological factors:
- disorders of brain development: prenatal and perinatal damage (for example, minimal cerebral dysfunction) can affect the development of the disease (complications of pregnancy and childbirth)

— neuropathology/imaging:
morphological changes in the brain are often observed (expansion of the internal and external cerebrospinal fluid space, for example, ventricles and lateral ventricles of the brain, structural limbic defects, reduction of frontotemporal volume)
functional diagnostics (MRI) shows metabolic hypofrontality and neural dysfunction (among others, cortical association area disorders)
When emotionally stimulated, limbic regions, in contrast to healthy ones, show lower activation—an affective nuclear deficit. In autism, there is presumably a disorder at the “neural level”

— biochemical correlate of schizophrenic symptoms: the significance of biogenic amines:
imbalance theory: inequality of local neurotransmitter activity and differences in distribution patterns

best known is the dopamine hypothesis = excess activity of dopamine central nervous structures in the mesolimbic, nigrostriatal, tuberoinfandibular systems
Arguments: the antipsychotic effect of antipsychotics is based on the blockade of postsynaptic dopamine receptors (D2) in the mesolimbic system, the occurrence of acute symptoms through hallucinogens and stimulants that increase dopamine neurotransmission (“models of psychosis” induced by narcotics, for example, LSD or amphetamines)

Hypothesis of glutamate deficiency in a small group of patients with schizophrenia
- immune inflammatory process?

Neuropsychology:
- “filter function disorder”: information processing disorders (major cognitive disorder), weakness of selective attention/irrelevant information filter function and disorders of reactionary and associative hierarchies
- detection of this disorder through event-evoked/event-related potentials; stabilization with antipsychotics

Psychosocial (peristatic) factors:
— the most reliable results are from studies confirming an increased risk of relapse in schizophrenics living in families with a high level of emotional expression (emotional overload, excessive emotional contact, intrusive overprotection, excessive protectiveness or hostile rejection of the patient). The initial involvement of psychosocial factors is supported by the temporal association between conflict or stress and the onset of schizophrenic illness, without specific “life events” being identified

Social genetic theories: growing up in a single-parent family, coming from a low social class, social isolation, “bachelor life” (social stress) are considered risk factors

Important: Psychosocial factors additionally influence the period of manifestation, course and prognosis rather than the origin of the disease.

Classification of schizophrenia

"Schizophrenia Spectrum"
- paranoid or non-paranoid forms
- positive/plus- (type I) or negative/minus-symptoms (type II, Crow)
- unsystematic schizophrenia (affective paraphrenia) or symptomatic schizophrenia (Leonhard)

Plus and minus symptoms in schizophrenic psychoses

Differences in clinical presentation:
— hallucinatory-paranoid form: delusions and hallucinations are characteristic, other symptoms are either less significant or absent altogether

— catatonic schizophrenia:
a) based on oscillations between catatonic stupor and catatonic excitation: danger of transition to pernicious catatonia
b) is currently diagnosed less frequently (4-8% of all schizophrenic psychoses)

— hebephrenic schizophrenia:
a) characterized by affect disorders (absurd affect) and formal thinking disorders
b) there are often violations of social behavior
c) appearance in adolescence:
- residual schizophrenia: personality changes in the form of decreased motivation, cognitive impairment and social isolation
- simple schizophrenia: occurs with a small number of symptoms - with no productive symptoms

Definition of schizophrenia. Etiology, pathogenesis, epidemiology

Schizophrenia. Affective disorders.

1. Definition of schizophrenia. Etiology, pathogenesis, epidemiology.

2. Symptomatology of schizophrenia: productive and negative symptoms.

3. Types of course of schizophrenia.

4. Remissions in schizophrenia.

5. Affective disorders.

Schizophrenia (schisis – splitting, phren – soul, mind) – endogenous progressive mental illness, manifested by specific personality changes and a variety of productive symptoms.

According to etiology, schizophrenia refers to endogenous diseases , i.e. occurs against the background of a hereditary predisposition, which is realized under the influence of various physical or mental provoking factors ( stress diathesis theory schizophrenia), age-related crises or spontaneously. External factors also contribute to the development of exacerbations of the disease.

Hereditary predisposition suggests the presence relatives of the patient have a higher risk of developing schizophrenia than in the population. If one parent has schizophrenia, the risk for the child is about 15%, for both – about 50%. If one of the monozygotic twins is sick, then the risk of disease for the second does not exceed 80%, i.e. it is not absolute (the role of exogenous provoking factors).

At the core pathogenesis schizophrenia is due to disturbances in neurotransmitter transmission carried out by dopamine, serotonin, norepinephrine, etc. (this is confirmed by the effectiveness of antipsychotics). The main role is given to dopamine. Activation of dopamine transmission in the mesolimbic pathway is associated with the development of psychotic symptoms, and inhibition of transmission in the mesocortical pathway is associated with the development of negative disorders.

Identified morphological changes in the brains of patients with schizophrenia: mild atrophy of gray matter (especially the frontal lobes and hippocampus) along with an increase in the volume of white matter and ventricles. However, the relationship between morphological changes and the clinic has not yet been established. The diagnosis of schizophrenia is made only clinically without pathological confirmation.

Schizophrenia is progressive disease, i.e. it leads to a steadily increasing disintegration of the psyche. Its pace may vary. This decay leads to the loss of unity between mental processes, the formation specific personality changes , up to schizophrenic dementia (“a car without a driver”, “a book with tangled pages”). Memory and intelligence do not suffer in schizophrenia, but the ability to use them is impaired. Patients with schizophrenia behave strangely, are characterized by unusual and unpredictability of emotional reactions and statements (they do not understand the context of the situation, they do not know how to read emotions on faces). These specific features of schizophrenia were first described by Eugene Bleuler (4 “A” - associations, affect, ambivalence, autism), he also proposed this term. That's why schizophrenia is called "Bleuler's disease."

In addition to specific personality changes, schizophrenia manifests itself in a variety of ways. productive symptoms (delusions, hallucinations, depression, mania, catatonia, etc.). These symptoms are less specific because also occur in other diseases.

In schizophrenia, there are no symptoms characteristic of organic brain damage (paroxysms, memory loss, psychoorganic syndrome).

Prevalence schizophrenia is about 1%. This indicator is common to all countries of the world and does not depend on national, cultural, economic and other conditions. About 2/3 of patients are under the supervision of psychiatrists, i.e., if we focus on the accounting population, then the prevalence is about 0.6% of the population.

Age onset of the disease – from 14 to 35 years. Peak incidence is 20-30 years. Schizophrenia rarely appears in childhood (although cases of schizophrenia in the first years of life have been described). After 40 years, the risk of developing the disease decreases sharply.

Men and women get sick equally often, but severe continuous forms of schizophrenia are 4 times more common in men.

In terms of social consequences, schizophrenia is a very serious disease. A significant proportion of people with mental disabilities suffer from schizophrenia.

2. Symptomatology of schizophrenia: productive and negative symptoms.

Clinical manifestations of schizophrenia are divided into two groups.

1. Obligate symptoms . These are mandatory symptoms characteristic of schizophrenia. Their appearance makes the diagnosis certain. They can be presented in whole or in part, appear earlier or later, and have different severity. At its core it is - negative symptoms(manifestations of mental breakdown). Modern drugs have virtually no effect on them. The following groups of obligate symptoms are distinguished ( it is necessary to decipher the meaning of the terms):

· thinking disorders: sperrung, mentism, slippage, fragmentation, verbigeration, symbolic thinking, neologisms, reasoning;

· pathology of emotions: decrease in emotional resonance up to emotional dullness, inadequacy of emotions, paradoxicality of emotions (symptom of “wood and glass”), ambivalence;

· disturbances of volitional activity: hypobulia (decreased energy potential), symptom of drift (subordination to external circumstances), ambitendence;

· autism(separation from reality, withdrawal into the inner world).

2. Optional symptoms . These symptoms are additional, i.e. they are less specific for schizophrenia and may occur in other diseases. This - productive symptoms(delusions, hallucinations). However, some of them are considered more or less typical of schizophrenia. Due to the fact that it is easier to identify productive symptoms than negative ones, today productive symptoms (rank I symptoms) are used as the main diagnostic criteria for schizophrenia. These include:

· taking away thoughts, putting in thoughts, sounding thoughts;

· ridiculous crazy ideas (communication with aliens, weather control).

To make a diagnosis, the presence of one of the four listed symptoms for at least 30 days is sufficient.

The remaining productive symptoms (other types of hallucinations, persecutory delusions, catatonia, depression, mania) are of auxiliary value for diagnosis.

Schizophrenia: etiology, diagnosis, treatment, examination (page 1 of 3)

ETIOLOGY AND PATHOGENESIS

LABOR AND FORENSIC PSYCHIATRIC EXAMINATION

According to modern concepts, schizophrenia belongs to a group of diseases with a hereditary predisposition. There is a significant accumulation of schizophrenic psychoses and personality anomalies in families of patients with schizophrenia, as well as high concordance in identical twin pairs. However, to date, the type of inheritance remains unclear. At the same time, an undoubted role in the manifestation of the disease is played by the influence of the external environment, as well as general biological changes in connection with somatic diseases and endocrine-age factors.

The specific pathogenetic mechanisms of the disease cannot be considered established, but most modern researchers believe that the cause of psychoses is disorders of neurotransmitter metabolism. In this regard, there are several different hypotheses linking schizophrenia with a disturbance in the metabolism of biogenic amines or their enzymes (catecholamines, indoleamine, MAO, etc.). In connection with the discovery of a new class of neuroreceptors and their ligands (morphine, benzodiazepine, etc.), intensive research is being conducted regarding their possible role in the development of pathology of mental activity, including in the pathogenesis of schizophrenia. Along with this, a number of biological anomalies in the constitutions of patients and their relatives (membrane insufficiency, changes in autoimmune reactions), expressed in the production of anti-brain antibodies in the patient’s body that can damage brain tissue, have been established. All these factors are more likely to be predispositional; their role in the manifestation of the disease has not been established.

In addition to biological hypotheses and theories, various theories of the psycho- and sociogenesis of schizophrenia are still widespread in the West. These include the psychoanalysis of S. Freud and the psychodynamic concept of A. Meyer, who consider schizophrenia as a special development of personality as a result of early (childhood) interpersonal conflict, mainly sexual. This group also includes modern vulgar sociological concepts of schizophrenia as a consequence of family or social conflict. Philosophical-phenomenological, “anthropological” theories of schizophrenia as a special type of existence (existential model) have become less widespread. All these ultimately idealistic concepts are, from a scientific point of view, unproven and unproductive, and the medical practice they engendered turned out to be untenable.

The diagnosis of schizophrenia and its differentiation from other mental illnesses is based on characteristic personality changes, psychopathological features of the syndromes, as well as the characteristics of the pathokinesis of the latter.

The history of the study of schizophrenia is associated with the search for specific disorders characteristic only of this disease - “intrapsychic ataxia”, “hypotonia of consciousness”, “weakening of the intentional sphere”, a description of a peculiar defect, as well as a description of the characteristics of the course of forms and variants of this disease.

The range of negative disorders typical of schizophrenia is quite wide: autism, reduction of energy potential, emotional deficiency, “drift” phenomena (a kind of passive submission), characteristic thinking disorders. In addition to autism, which is characterized by a separation from reality, life in a special world of subjective ideas, it is also possible to develop “inside-out autism” (regressive syntony) with inappropriate naked frankness regarding intimate aspects of life.

A reduction in energy potential is a fairly common sign of negative disorders, manifested in a sharp weakening or loss of mental activity, which is directly related primarily to productivity and the ability to engage in intellectual activity.

Emotional deficiency manifests itself in a fairly wide range of disorders, from some leveling of emotional reactions to pronounced emotional dullness. Often, rational contacts associated with calculation and egocentric tendencies are preserved. The phenomenon of “wood and glass” is possible: a combination of emotional dullness in relation to others with extreme sensitivity and vulnerability in relation to one’s own personality.

The phenomena of drift, characteristic of schizophrenia, are manifested by increasing passivity, subordination, the inability to make independent decisions, to manage one’s actions and actions. Characterized by thinking disorders, such as interruptions of thoughts, slippages, amorphous concepts and conclusions, fragmented thinking.

Negative changes often manifest themselves in the external appearance of patients: they look strange, eccentric, pretentiously mannered or sloppy, self-centered, and often prone to peculiar, strange, unusual hobbies.

As already noted, the diagnosis of schizophrenia is made not only on the basis of personality changes characteristic of the disease, but is also determined by the characteristics of the psychopathological picture of conditions and their dynamics, as well as the progression of the disease; the latter is manifested by a complication of the clinical picture, a change in the nature of the registers from lighter to more severe, reflecting a large volume and depth of mental disorders, as well as a deepening of deficiency (negative) disorders that can occur earlier than the manifestation of the disease, increase as the process progresses, with a paroxysmal nature the disease gets worse from attack to attack.

DIFFERENTIAL DIAGNOSIS IN LOW PROGRESSIVE SCHIZOPHRENIA

The difficulty lies primarily in the fact that low-progressive schizophrenia, like neuroses, psychopathy and reactive states, from our point of view, can be classified as borderline psychiatry. When carrying out a differential diagnosis of low-progressive schizophrenia with the conditions listed above, a thorough analysis of the hereditary burden, the characteristics of the premorbid, its dynamics, the development of manifest disorders is necessary: ​​it is extremely important to identify positive signs, often rudimentary and transient, characteristic of psychotic forms of schizophrenia (senestopathies, hallucinations of general feelings, verbal hallucinations, ideas of relation, persecution and influence, as well as states of acutely developing unmotivated anxiety, acute depersonalization episodes, etc.). With low-progressive schizophrenia, constitutional features often appear that are uncharacteristic for the premorbid patient (psychasthenic, hysterical, explosive, etc.), unusual for the patient before. These features often become important for diagnosis.

The diagnosis of low-progressive schizophrenia is often helped by identifying in patients phases atypical for psychopathy with erased affect, the predominance in them not so much of affective disorders themselves, but of psychopathic-like, neurotic and somato-vegetative disorders.

The appearance of schizoid traits unusual for the patient, adaptation disorders, significant changes in character, unmotivated changes in professions, as well as the increase in negative disorders characteristic of schizophrenia, as a rule, are decisive reference points in the diagnosis of low-progressive schizophrenia.

DIFFERENTIAL DIAGNOSIS FOR ATTACK-like-PROGREDIENT AND RECURRENT SCHIZOPHRENIA

Due to the fact that schizophrenia quite often takes on the character of a paroxysmal course, and attacks occur with a predominance of affective disorders, it seems necessary to differentiate the diagnosis with manic-depressive psychosis. When differentiating manic-depressive psychosis from schizophrenia, primarily from recurrent schizophrenia, it is necessary to take into account the entire set of data about the disease: the nature of the pre-manifest period, the structure of attacks, the presence or absence of changes in the interictal period and the dynamics of personality characteristics throughout the course of the disease. The appearance in the structure of an attack of acute sensory delusions, hallucinations, delusions of persecution, phenomena of mental automatism, catatonic disorders, as well as the formation and increase in personality changes during the interictal period, tilts the diagnosis in favor of schizophrenia. The study of heredity has a certain significance in resolving the issue of diagnosis.

Paroxysmal schizophrenia must be differentiated from symptomatic and, first of all, from protracted (intermediate) endoform psychoses. Issues of differentiation are extremely complex due to the fact that in recent years endoform symptomatic psychoses have become casuistry; they should be distinguished from endogenous psychoses provoked by various types of exogenies.

The presence in the structure of endoform psychosis of asthenia, weakness, episodes of acute symptomatic psychoses in the evening and at night, as well as the known specificity of delusional constructs cannot be regarded as supporting differential diagnostic criteria, because there are indisputable facts about the modification of the structure of the endogenous psychopathological syndrome under the influence of somatic disease [Zhislin S.G., 1965].

Schizophrenia is one of the most common mental illnesses. However, studying the prevalence of schizophrenia is associated with a number of difficulties. Some of them are explained by the existence of various diagnostic approaches that determine the traditions of national and intranational schools, others by serious methodological difficulties in fully identifying patients in the population.

116. Epidemiology of schizophrenia.

Schizophrenia- a chronic mental illness, which is based on a hereditary predisposition, beginning mainly at a young age, characterized by a variety of clinical symptoms with productive and negative syndromes, a tendency towards progressive progression and often leading to persistent impairment of social adaptation and ability to work. Available statistical data and the results of epidemiological studies allow us to conclude that its distribution rates are similar in all countries and amount to 1–2% of the total population. The initial assumption that schizophrenia is less common in developing countries has not been confirmed. The results of studies specifically conducted in developing countries revealed a similar number of patients with schizophrenia (1 new case per 1000 people annually) with the number of patients with schizophrenia in European countries. There is only a difference in the representativeness of certain types of clinical manifestations of the disease. Thus, among patients living in developing countries, acute conditions with confusion, catatonic, etc. are more common.

The average age of onset of the disease is 20 - 25 years for men and 25 - 35 years for women. There is a family predisposition to schizophrenia. If both parents are sick, then the child’s risk of illness is 40-50%, if one of them is sick - 5%. First-degree relatives of people with schizophrenia are diagnosed with the disease much more often than third-degree relatives (cousins), who are almost as likely to have schizophrenia as the general population.

117. Modern ideas about the etiology and pathogenesis of schizophrenia.

The etiology and pathogenesis of schizophrenia became the subject of special study soon after the disease was identified as a separate nosological unit. E. Kraepelin believed that schizophrenia occurs as a result of toxicosis and, in particular, dysfunction of the gonads. The idea of ​​the toxic nature of schizophrenia was developed in other subsequent studies. Thus, the occurrence of schizophrenia was associated with a violation of protein metabolism and the accumulation of nitrogenous breakdown products in the body of patients. In relatively recent times, the idea of ​​the toxic nature of schizophrenia was presented by an attempt to obtain a special substance, thoraxein, in the blood serum of patients with this disease. However, the idea that there is a specific substance in patients with schizophrenia has not received further confirmation. Toxic products are present in the blood serum of patients with schizophrenia, but they are not particularly specific, characteristic only of patients with schizophrenia.

In recent years, certain advances have been made in the biochemical study of schizophrenia, making it possible to formulate biochemical hypotheses for its development.

The most representative are the so-called catecholamine and indole hypotheses. The first are based on the assumption of the role of dysfunction of norepinephrine and dopamine in the mechanisms of disruption of neurobiological processes in the brain of patients with schizophrenia. Proponents of the indole hypothesis believe that since serotonin and its metabolism, as well as other indole derivatives, play an important role in the mechanisms of mental activity, dysfunction of these substances or components of their metabolism can lead to the occurrence of schizophrenia. In essence, the idea of ​​a connection between the schizophrenic process and dysfunction of enzyme systems involved in the metabolism of biogenic amines is also close to the concepts described above.

personal adaptation to life. The impossibility of full adaptation is explained by a special personality defect formed as a result of incorrect interpersonal relationships within the family in early childhood. Such ideas about the nature of schizophrenia have been refuted. It has been shown that the risk of schizophrenia in children who have adapted at an early age to other families is not due to the peculiarities of intrafamily relationships in them, but to hereditary burden.