How is schizophrenia inherited? Is schizophrenia a hereditary disease or not? Inheritance of schizophrenia

People suffering from mental illnesses and disorders are not uncommon. Inadequate thinking processes, incoherent thoughts, hallucinations are frequent companions of such diseases.

From time immemorial, many generations have been interested in the role of heredity in mental illness. It was not uncommon to have discussions among friends about the oddities of this or that person, where facts of inappropriate behavior and disorders in one of his relatives surfaced. The thing is that in the case of a marriage with a young lady or gentleman whose family had relatives suffering from mental illness, there was a risk of mental disorders in the children born - their descendants.

This problem is still relevant today. One of the most common is schizophrenia. A disease that equally affects both males and females. Women - in a later age category and to a less severe degree. At least 1% of the world's inhabitants suffer from the disease. The disease also affects children. And it’s no wonder that many people directly related to this type of disorder are concerned about the question: is schizophrenia inherited?

Young people getting married, one of whom suffers from the disorder, and their relatives and friends turn to psychiatrists for answers, hoping to dispel their doubts about the possibility of manifestations of schizophrenia in their expected offspring.

At various forums, both among interested parties, their environment, and among medical specialists, the problem is being raised - schizophrenia: is it inherited?

Many sources on mental disorders highlight several causes of this disease.

The data from numerous studies in the field of schizophrenia are mixed. The mechanisms of this disease are currently being comprehensively studied. Diagnostic studies are carried out on patients of various categories, various versions are put forward, symptoms are interpreted, and conclusions are drawn. The results of most studies still confirm the fact that schizophrenia is inherited. The number of children affected in families with parents suffering from the disorder is quite significant and can be, according to some trials, up to 20%. The risk of diseases is most likely in children, as well as adults, in families where their parents, siblings and brothers, that is, direct relatives, are sick. The risk of morbidity among twins is very high. This cannot be ignored by researchers and confirms the fact that this disorder is highly hereditary. However, some tests conducted, however, cast doubt on this factor, motivating their conclusions by the fact that a large number of people get sick without having among their relatives those affected by this disease. Not long ago, researchers from (United States of America) expressed their doubts and made assumptions in this area.

Recently, researchers who have asked and are interested in the problem: “is schizophrenia inherited or not” are more inclined to the influence of the environment, including those suffering from this disease, on the development of the disease in a person. Pointing out in his tests the importance of the environment in which the person suffering from the disease grew up, and the degree to which he was raised by a sick relative.

However, no clear conclusions have been made to date to deny the factor of heredity in the development of the disease. This does not allow us to fully refute the theory that schizophrenia is inherited.

The disease cannot be cured, and such a patient often becomes a big burden and problem for loved ones.

Many people who have relatives with this type of disorder fear for the health of future generations, and fear that under unfavorable conditions the disease will manifest itself in them.

Such thoughts and fears are not completely unfounded, since since ancient times it has become known that if there is at least one crazy person in the family, then the deviation will sooner or later manifest itself in the form of mental pathology in children or grandchildren.

Such a family was usually bypassed, and marrying into its members was tantamount to a curse. Many in those days believed that God was punishing an entire family for the sins of their ancestors and taking away a person’s reason.

Nowadays, no one believes in this, but many consider entering into such a marriage very undesirable. For this reason, information about a relative who suffers from a mental disorder is usually carefully hidden.

However, only specialists can make predictions about the likelihood of a baby having such deviations.

Causes of schizophrenia

The likelihood of getting sick can be noted not only as a result of a burdened seminal history; the trigger for schizophrenia can be:

maternal fasting during pregnancy;
emotional and physical trauma suffered by the child during childhood;
birth trauma;
poor environmental conditions;
drug and alcohol use;
social isolation;
intrauterine development disorder.

Who is more likely to get sick?

Many people, completely unreasonably, believe that the disease occurs as a result of:

only hereditary factor;
transmitted through generations, that is, from grandfathers to grandchildren;
the presence of female patients (that is, schizophrenia is transmitted through the female line);
the presence of men suffering from schizophrenia (only from man to man).

In fact, such statements are devoid of any scientific basis. The risk of the disease equal to one percent remains in people with completely normal heredity.

How is schizophrenia actually transmitted? The likelihood becomes slightly higher if you have sick relatives. If the family has cousins or sisters, as well as aunts and uncles with an officially confirmed diagnosis, then we are talking about the possible development of the disease in two percent of cases.

If a half-brother or sister has pathology, the probability increases to six percent. The same figures can be cited when it comes to parents.

The highest likelihood of developing the disease is among those who have sick not only their mother or father, but also their grandparents. If a deviation is detected in fraternal twins, the possibility of developing schizophrenia in the second reaches seventeen percent.

The probability of having a healthy child, even if there is a sick relative, is quite high. Therefore, you should not deny yourself the happiness of becoming parents. But in order not to take risks, you should consult a geneticist.

The highest probability, almost 50%, occurs when one of the parents and both representatives of the older generation - grandparents - are sick.

The same percentage is the possibility of developing the disease in an identical twin when schizophrenia is diagnosed in the second.

Despite the fact that the probability of illness in the presence of several patients in the family remains quite high, these are still not the most terrible indicators.

If we compare the data with a hereditary predisposition to cancer or diabetes, we can understand that they are still much lower.

Features of the examination

For various hereditary pathologies, conducting research is not particularly difficult. This happens because a specific gene is responsible for the development of a particular disease.

In schizophrenia, this is difficult to do, since this occurs at the level of different genes, and in each patient completely different mutations may be responsible for this.

Experts note that, according to their observations, the degree of likelihood of mental disorders in a child depends on the number of altered genes. For this reason, one should not believe stories that the disease is transmitted through the male or female line.

In fact, even experienced specialists cannot know which gene is responsible for schizophrenia in each specific case.

Most types of mental disorders develop quite slowly, and the diagnosis is made several years after the appearance of the first nonspecific symptoms.

Exercise from a psychological test for schizophrenia

Conclusions

We can safely say that the hereditary form of schizophrenia develops as a result of the general interaction of several genes, which, when combined, cause a predisposition to this pathology.

But even the presence of damaged and altered chromosomes cannot speak of a 100% probability of developing the disease. If a person has normal living conditions since childhood, the disease may never manifest itself.

Schizophrenia is a hereditary disease, methods of diagnosis and treatment

The transmission of mental illness by inheritance is far from an idle issue. Everyone wants themselves, their loved ones and their children to be healthy physically and mentally.

What should you do if among your relatives or the relatives of your significant other there are patients with schizophrenia?

There was a time when there was talk that scientists had found 72 genes for schizophrenia. Several years have passed since then and the research data have not been confirmed.

Although schizophrenia is considered a genetically determined disease, structural changes in certain genes have not been found. A set of defective genes has been identified that disrupt brain function, but it cannot be said that this leads to the development of schizophrenia. That is, it is not possible, after conducting a genetic examination, to say whether a person will develop schizophrenia or not.

Although there is a hereditary condition for the disease of schizophrenia, the disease develops from a complex of factors: sick relatives, the character of the parents and their attitude towards the child, upbringing in early childhood.

Since the origin of the disease is unknown, medical scientists have identified several hypotheses for the occurrence of schizophrenia:

Genetic – in twin children, as well as in families where parents suffer from schizophrenia, more frequent manifestations of the disease are observed.
Dopamine: human mental activity depends on the production and interaction of the main mediators, serotonin, dopamine and melatonin. In schizophrenia, there is increased stimulation of dopamine receptors in the limbic region of the brain. However, this causes the manifestation of productive symptoms, in the form of delusions and hallucinations, and does not in any way affect the development of negative symptoms - apatho-abulic syndrome: decreased will and emotions. ;
Constitutional is a set of psychophysiological characteristics of a person: gynecomorphic men and pyknic-type women are most often found among patients with schizophrenia. Patients with morphological dysplasia are considered to be less responsive to treatment.
The infectious theory of the origin of schizophrenia is currently of more historical interest than it has any basis. Previously, it was believed that staphylococcus, streptococcus, tuberculosis and E. coli, as well as chronic viral diseases reduce human immunity, which is supposedly one of the factors in the development of schizophrenia.
Neurogenetic: a mismatch between the work of the right and left hemispheres due to a defect in the corpus callosum, as well as a violation of the fronto-cerebellar connections leads to the development of productive manifestations of the disease.
Psychoanalytic theory explains the appearance of schizophrenia in families with a cold and cruel mother, an oppressive father, a lack of warm relationships among family members, or their manifestation of opposing emotions to the same behavior of the child.
Environmental – mutagenic influence of unfavorable environmental factors and lack of vitamins during fetal development.
Evolutionary: increasing the intelligence of people and increasing technocratic development in society.

The likelihood of developing schizophrenia

The probability of developing schizophrenia in persons who do not have a sick relative is 1%. And for a person with a family history of schizophrenia, this percentage is distributed as follows:

one of the parents is sick - the risk of getting sick will be 6%,
father or mother is sick, as well as grandparents - 3%,
a brother or sister suffers from schizophrenia – 9%,
either the grandfather or grandmother is sick - the risk is 5%,
when a cousin (brother) or aunt (uncle) gets sick, then the risk of disease is 2%,
if only the nephew is sick, the probability of schizophrenia will be 6%.

This percentage only indicates the possible risk of schizophrenia, but does not guarantee its manifestation. As you go, the largest percentage is when parents and grandparents suffered from schizophrenia. Fortunately, this combination is quite rare.

Schizophrenia is hereditary in the female or male line

A reasonable question arises: if schizophrenia is a genetically dependent disease, is it transmitted through the maternal or paternal line? According to the observations of practicing psychiatrists, as well as statistics from medical scientists, such a pattern has not been identified. That is, the disease is transmitted equally through both the female and male lines.

Moreover, it more often manifests itself under the influence of combined factors: hereditary and constitutional characteristics, pathology during pregnancy and child development in the perinatal period, as well as characteristics of upbringing in childhood. Chronic and severe acute stress, as well as alcoholism and drug addiction can be provoking factors for the manifestation of schizophrenia.

Hereditary schizophrenia

Since the true causes of schizophrenia are not known and not one of the theories of schizophrenia fully explains its manifestations, doctors are inclined to classify the disease as a hereditary disease.

If one of the parents has schizophrenia or there are known cases of the disease among other relatives, before planning a child, such parents are advised to consult a psychiatrist and geneticist. An examination is carried out, the probabilistic risk is calculated and the most favorable period for pregnancy is determined.

We help patients not only with inpatient treatment, but also try to provide further outpatient and socio-psychological rehabilitation, telephone number of the Preobrazhenie clinic.

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Is schizophrenia inherited?

Schizophrenia is a psychosis of an endogenous nature, a mental disorder that is particularly severe.

This disease develops under the influence of functional changes occurring in the human body; the influence of environmental factors is not taken into account. Schizophrenia occurs over a fairly long period of time, developing from mild to more severe stages. The changes occurring in the psyche are constantly progressing, as a result of which patients can completely lose any connection with the outside world.

This is a chronic disease that leads to a complete disorder of mental functions and perception, however, it is a mistake to believe that schizophrenia causes dementia, since the patient’s intelligence, as a rule, not only remains at a high level, but can be much higher than that of healthy people. In the same way, memory functions do not suffer; the senses work normally. The problem is that the cerebral cortex does not process incoming information correctly.

Reasons

Schizophrenia is inherited - is this true, is this statement worth believing? Are schizophrenia and heredity somehow related? These questions are very relevant in our time. This disease affects about 1.5% of the inhabitants of our planet. There is, of course, a possibility that this pathology can be transmitted from parents to children, but it is extremely small. There is a much greater chance that the child will be born completely healthy.

Moreover, quite often this mental disorder occurs in initially healthy people, in whose family no one has ever had schizophrenia, that is, they do not have a genetic tendency to this disease. In these cases, schizophrenia and heredity are in no way connected, and the development of the disease can be caused by:

brain injuries - both birth and postpartum;
serious emotional trauma suffered at an early age;
environmental factors;
severe shocks and stress;
alcohol and drug addiction;
anomalies of intrauterine development;
social isolation of the individual.

The causes of this disease themselves are divided into:

biological (viral infectious diseases suffered by the mother during the process of bearing a child; similar diseases suffered by the child in early childhood; genetic and immune factors; toxic damage from certain substances);
psychological (until the manifestation of the disease, a person is closed, immersed in his inner world, has difficulty communicating with others, is prone to lengthy reasoning, has difficulty trying to formulate a thought, is characterized by increased sensitivity to stressful situations, is sloppy, passive, stubborn and suspicious, pathological vulnerable);
social (urbanization, stress, characteristics of family relationships).

The connection between schizophrenia and heredity

Currently, quite a lot of different studies have been conducted that can confirm the theory that heredity and schizophrenia are closely related concepts. It is safe to say that the likelihood of this mental disorder occurring in children is quite high in the following cases:

detection of schizophrenia in one of the identical twins (49%);
diagnosis of the disease in one of the parents or both representatives of the older generation (47%);
detection of pathology in one of the fraternal twins (17%);
detection of schizophrenia in one of the parents and at the same time in someone from the older generation (12%);
detection of the disease in an older brother or sister (9%);
detection of the disease in one of the parents (6%);
diagnosing schizophrenia in a nephew or niece (4%);
manifestations of the disease in aunts, uncles, and cousins (2%).

Thus, we can come to the conclusion that schizophrenia is not necessarily inherited, and the chance of giving birth to a healthy child is quite high.

When planning a pregnancy, you should consult a geneticist.

Diagnostic methods

When we talk about genetic diseases, we most often mean illnesses caused by the influence of one specific gene, which is not so difficult to identify, as well as to determine whether it can be transmitted to a future child during the process of conception. If it comes to schizophrenia, then everything is not so simple, since this pathology is transmitted through several different genes at once. Moreover, for each patient, the number of mutated genes is different, as is their variety. The risk of developing schizophrenia directly depends on the number of defective genes.

In no case should one trust the assumption that a hereditary disease is transmitted strictly through generations or only through the male or female line. This is all just guesswork. To date, no researcher knows which gene determines the presence of schizophrenia.

So, hereditary schizophrenia arises as a result of the mutual influence of a group of genes on each other, which develop in a special way and cause a predisposition to the disease.

It is not at all necessary that psychosis will develop, even if defective chromosomes are present in large numbers. Whether a person gets sick or not is influenced by both the quality of his life and the characteristics of the environment. Schizophrenia, inherited, is primarily an innate predisposition to the development of mental disorders that can arise under the influence of various factors due to physiological, psychological and biological reasons.

Is schizophrenia hereditary or not?

Schizophrenia is a well-known mental illness. Several tens of millions of people worldwide suffer from this disease. Among the main hypotheses for the occurrence of the disease, particularly close attention is drawn to the question: can schizophrenia be inherited?

Heredity as a cause of the disease

Concern about whether schizophrenia is inherited is quite justified for people in whose families cases of the disease have been recorded. Also, possible bad heredity is a concern when getting married and planning offspring.

After all, this diagnosis means serious mental disturbances (the word “schizophrenia” itself is translated as “split consciousness”): delusions, hallucinations, motor impairment, manifestations of autism. A sick person becomes unable to think adequately, communicate with others and needs psychiatric treatment.

The first studies of the familial spread of the disease were carried out back in the centuries. For example, in the clinic of the German psychiatrist Emil Kraepelin, one of the founders of modern psychiatry, large groups of schizophrenic patients were studied. The works of the American professor of medicine I. Gottesman, who studied this topic, are also interesting.

There were initially a number of difficulties in confirming the “family theory”. In order to reliably determine whether a disease is genetic or not, it was necessary to recreate the complete picture of ailments in the human family. But many patients simply could not reliably confirm the presence or absence of mental disorders in their family.

Perhaps some of the patients’ relatives knew about the mental disturbances, but these facts were often carefully hidden. Severe psychotic illness in relatives imposed a social stigma on the entire family. Therefore, such stories were hushed up both for descendants and for doctors. Often, ties between a sick person and his relatives were completely severed.

And yet, the family sequence in the etiology of the disease was traced very clearly. Although doctors, fortunately, do not give an unequivocally affirmative answer that schizophrenia is necessarily inherited. But genetic predisposition is among the main causes of this mental disorder.

Statistics of the “genetic theory”

To date, psychiatry has accumulated enough information to come to certain conclusions on the issue of how schizophrenia is inherited.

Medical statistics say that if there is no clouding of reason in your family line, then your probability of getting sick is no more than 1%. However, if your relatives did have such diseases, then the risk increases accordingly and ranges from 2 to almost 50%.

The highest rates were recorded in pairs of identical (monozygotic) twins. They have completely identical genes. If one of them gets sick, then the second has a 48% risk of developing pathology.

Much attention from the medical community was attracted by a case described in works on psychiatry (monograph by D. Rosenthal et al.) back in the 70s of the 20th century. The father of four identical twin girls suffered from mental disorders. The girls developed normally, studied and communicated with peers. One of them did not graduate from the educational institution, but three completed their studies at school successfully. However, at the ages of 20–23 years, schizoid mental disorders began to develop in all sisters. The most severe form - catatonic (with characteristic symptoms in the form of psychomotor disorders) was recorded in a girl who had not completed school. Of course, in such striking cases, psychiatrists simply do not have doubts whether this is a hereditary disease or an acquired one.

A descendant has a 46% chance of getting sick if one of the parents (or mother, or father) is sick in his family, but both grandparents are sick. In this case, a genetic disease in the family has already been virtually confirmed. A person who had both a father and mother with mental illness in the absence of similar diagnoses among their parents would have a similar percentage of risk. Here it is also quite easy to see that the patient’s illness is hereditary and not acquired.

If in a pair of fraternal twins one of them has a pathology, then the risk of the second getting sick will be 15-17%. This difference between identical and fraternal twins is associated with the same genetic makeup in the first case, and a different one in the second.

A person with one patient in the first or second generation of the family has a 13% chance. For example, the likelihood of a disease occurring is transmitted from the mother with a healthy father. Or vice versa - from the father, while the mother is healthy. Option: both parents are healthy, but one of the grandparents is mentally ill.

9%, if your sibling fell victim to a mental illness, but no other similar abnormalities were found in the closest relatives.

From 2 to 6% the risk will be for someone in whose family there is only one case of pathology: one of your parents, a half-brother or sister, an uncle or aunt, one of your nephews, etc.

Pay attention! Even a 50% probability is not a verdict, not 100%. So you shouldn’t take folk myths about the inevitability of passing on diseased genes “across generations” or “from generation to generation” too seriously. At the moment, genetics still does not have sufficient knowledge to accurately state the inevitability of the occurrence of the disease in each specific case.

Which line is more likely to have bad heredity?

Along with the question of whether a terrible disease is inherited or not, the type of inheritance itself was closely studied. Through which line is the disease most often transmitted? There is a popular belief that heredity through the female line is much less common than through the male line.

However, psychiatry does not confirm such a guess. In the question of how schizophrenia is inherited more often - through the female line or through the male line, medical practice has revealed that gender is not decisive. That is, transmission of a pathological gene from mother to son or daughter is possible with the same probability as from father.

The myth that the disease is transmitted to children more often through the male line is associated only with the peculiarities of the pathology in men. As a rule, mentally ill men are simply more visible in society than women: they are more aggressive, there are more alcoholics and drug addicts among them, they experience stress and mental complications more severely, and they adapt less well in society after suffering mental crises.

About other hypotheses of the occurrence of pathology

Does it happen that a mental disorder affects a person in whose family there were absolutely no such pathologies? Medicine has clearly answered in the affirmative the question of whether schizophrenia can be acquired.

Along with heredity, among the main reasons for the development of the disease, doctors also name:

neurochemical disorders;
alcoholism and drug addiction;
a traumatic experience experienced by a person;
maternal illness during pregnancy, etc.

The pattern of development of a mental disorder is always individual. Whether the disease is hereditary or not is visible in each specific case only if all possible causes of the disorder of consciousness are taken into account.

Obviously, with a combination of bad heredity and other provoking factors, the risk of getting sick will be higher.

Additional information. Psychotherapist, Candidate of Medical Sciences Galushchak A. talks in more detail about the causes of pathology, its development and possible prevention.

What to do if you are at risk?

If you know for sure that you have an innate predisposition to mental disorders, you need to take this information seriously. It is easier to prevent any disease than to cure it.

Simple preventative measures are within the capabilities of anyone:

Lead a healthy lifestyle, give up alcohol and other bad habits, choose the optimal regime of physical activity and rest for yourself, control your diet.
Regularly see a psychologist, consult a doctor promptly if you have any unfavorable symptoms, and do not self-medicate.
Pay special attention to your mental well-being: avoid stressful situations and excessive stress.

Remember that a competent and calm attitude towards a problem makes the path to success in any business easier. With timely consultation with doctors, many cases of schizophrenia are successfully treated in our time, and patients get a chance for a healthy and happy life.

The ability of schizophrenia to transmit the characteristics of its development to descendants

A mental illness that manifests itself in constant variability of consciousness, activity, perception and progresses to disability is called schizophrenia. These diseases affect both men and women. The disorder includes a dozen common psychoses. Patients with this disease hear different voices of invisible people; They think that everyone around them knows about all their thoughts and can control them. This condition causes constant paranoia, self-isolation, and aggressive agitation. Depending on the severity of the disease, patients behave differently: some tirelessly talk about the strange and incomprehensible; others sit silently, I get the impression of healthy people. Both individuals cannot serve themselves or work in any organization.

Experts believe that schizophrenia and heredity are close brothers to each other, and some life circumstances (stress, lifestyle) can complement them.

So is it all hereditary or not?

“Schizophrenia is inherited,” this is what experts of the past believed. They argued: those who had relatives in their family with such a mental disorder, the illness would manifest itself sooner or later, and in the absence of such relatives, they assumed that the patient simply did not know about it.

Evidence from modern medicine refutes the fact that genes are to blame and states that only in half of cases schizophrenia is hereditary; in other cases, the disease occurs due to a persistent transformation of the genotype of the parent's germ cells and the reasons for their mutation are unknown.

Each cell of the body has 23 pairs of chromosomes and at conception, 2 copies of genes are transmitted (one from the father and mother). There is an assumption that only a few structural hereditary units have a risk of inheriting schizophrenia, but they do not have a big impact on the development of the disease. The process of disease formation not only from hereditary factors, but also from the environment:

Infectious diseases caused by viruses.
Poor nutrition of the embryo while in the womb.
Poor psychological situation in the family or at work.
Injuries to the child during childbirth.

Figures of hereditary schizophrenia

1% of the country's population has a group of mental disorders, but if parents have it, then the risk of developing the disease becomes 10 times greater. The risk of inheriting schizophrenia increases even more if second-degree relatives, for example, a grandmother or cousin, suffer from it. The peak risk is the disease of one of the homozygous twins (up to 65%).

The location of the chromosome in the gene is very important. A defect in chromosome 16 will have less destructive force on the brain than a defect in the 4th or 5th structural element of the cell nucleus.

Science and schizophrenia

Californian scientists conducted a study in which stem cells from mentally ill patients were taken. They were given different levels of development, their behavior was observed, creating unusual or stressful living conditions in an unnatural way. And for good reason! The study revealed oddities in the behavior and movement of these cells, that is, several groups of proteins.

According to scientists, the experiments should help in diagnosing schizophrenia in the early stages.

Is it possible to find out about the disease before the birth of the child?

Is schizophrenia a hereditary disease? Yes! But it is impossible to determine the probability of gene transmission during conception, since mental disorder is caused not only by defects in units of hereditary material, but also by other influencing factors. And the number of defective genes varies for each person. Therefore, there is definitely no need to worry about your children inheriting this disease.

In fact, it can be assumed that the likelihood of inheriting schizophrenia will be related to the number of defective units of hereditary material. The more there are, the higher the risk of getting the disease.

There is no clear answer as to whether schizophrenia is a hereditary disease or not. The disease remains to this day the most severe mental disorder that cannot be completely cured. As scientists did not struggle with experiments and research, they were never able to substantiate the etiology of schizophrenia, as a result of which there are no approved methods of treatment. The only thing that can be done for the patient is to conduct psychotherapy sessions with the addition of drug treatment. In especially severe cases, it is necessary to select a drug that will calm the patient and remove the danger to others.

A mental illness that manifests itself in constant variability of consciousness, activity, perception and progresses to disability is called schizophrenia. Both men and women suffer from these diseases. The disorder includes a dozen common psychoses. Patients with this disease hear different voices of invisible people; They think that everyone around them knows about all their thoughts and can control them. This condition causes constant paranoia, self-isolation, and aggressive agitation. Depending on the severity of the disease, patients behave differently: some tirelessly talk about the strange and incomprehensible; others sit silently, I get the impression of healthy people. Both individuals cannot serve themselves or work in any organization.

Experts believe that schizophrenia and heredity are close brothers to each other, and some life circumstances (stress, lifestyle) can complement them.

So is it all hereditary or not?

Infectious diseases caused by viruses.
Poor nutrition of the embryo while in the womb.
Poor psychological situation in the family or at work.
Injuries to the child during childbirth.

Figures of hereditary schizophrenia

Science and schizophrenia

According to scientists, the experiments should help in diagnosing schizophrenia in the early stages.

Is it possible to find out about the disease before the birth of the child?

Is schizophrenia inherited or not? This question remained unanswered for centuries. Many different studies by scientists from different countries were finally able to identify a connection with heredity. But here, too, it turned out that not everything is so simple; schizophrenia is not one of those diseases that are inherited using just one defective gene. In this case, a number of genes are involved, which in turn leads today to significant difficulties in identifying predisposition to the pathological process.

Facts about schizophrenia

The disease can have both hereditary and acquired etiology. Unfortunately, scientists still cannot name the exact cause of the development of the disease, despite long-term studies of patients and the use of their genetic material.

Schizophrenia is a chronic pathology that leads to mental disorders and disorders of thinking and perception. A pathology cannot be called dementia, since the intelligence of many remains at a high level. The activity of the senses, hearing and vision remains intact; the only difference from healthy people is the incorrect interpretation of incoming information.

In addition to genetic predisposition, there are a number of factors that can become the impetus for the first manifestations of pathology:

brain injuries, including postpartum;
social isolation;
shocks and stress;
environmental factor;
problems in the intrauterine development of the fetus.

Is there a risk of heredity?

The question of the heredity of mental pathologies is quite acute. And since schizophrenia is one of the most common types of mental illnesses, scientists pay special attention to this pathology.

Since ancient times, schizophrenia has caused fear among ordinary people; upon learning about the presence of relatives with this diagnosis, fearing negative heredity, they refused to marry. The opinion that schizophrenia is inherited in almost one hundred percent of cases is far from correct. There are many myths about heredity, as if the disease is transmitted through generations either only to boys, or, conversely, to girls. None of this is true. In fact, even people without negative heredity have a risk of getting sick; according to statistics, this is 1% of the healthy population.

Regarding heredity, there are also certain calculations of possible risk:

The greatest risk is for offspring who have a grandparent or one parent with a mental disorder. In this case, the risk rises to 46%;

48% have a risk of developing an identical twin, if pathology is detected in the second;
in fraternal twins this threshold drops to 17%;
if one of the parents and one of the grandparents is sick, the risk of the child developing the disease is 13%;
if the disease is diagnosed in a brother or sister, the risk of pathology increases from one to 9%;
pathology in one of the parents or in a half-sister or brother - 6%;
among nephews - 4%;
in uncles, aunts or cousins - the risk is 2%.

Is it all about genes or not?

Most genetic diseases transmitted by inheritance have a mild type of inheritance. There is no correct gene, and it is either passed on to descendants or not. But, in the case of schizophrenia, everything is different; the exact mechanism of its development has not yet been established. But according to research by geneticists, 74 genes have been identified that in one way or another may be involved in the development of the disease. So, the more of these 74 genes are defective, the higher the likelihood of the disease.

Genetically, there is no difference between a male or female descendant. In percentage terms before the disease, both sexes are equal. It was also found that the risk of the disease increases under the influence of several factors, not only hereditary, but also concomitant. For example, the manifestation of symptoms of pathology can be triggered by factors such as severe stress, drug addiction or alcoholism.

If a couple is planning a pregnancy and has a family history of schizophrenia, it is recommended that they be examined by a geneticist. With its help, there is no way to know for sure whether the heirs will have problems or not, but you can calculate the approximate probability of the child developing pathology and determine the best period of time for pregnancy.

In many ways, people suffering from schizophrenia are practically no different from healthy people. Only a few forms of pathology, in the acute stage, have pronounced mental abnormalities. During the period of remission, which is achieved by adequate treatment, the patient feels well and does not experience clinical manifestations of the disease. Despite the fact that schizophrenia is a chronic disease, the duration of remission can significantly exceed the period of exacerbation.

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The disease cannot be cured, and such a patient often becomes a big burden and problem for loved ones.

Many people who have relatives with this type of disorder fear for the health of future generations, and fear that under unfavorable conditions the disease will manifest itself in them.

However, only specialists can make predictions about the likelihood of a baby having such deviations.

Causes of schizophrenia

The likelihood of getting sick can be noted not only as a result of a burdened seminal history; the trigger for schizophrenia can be:

maternal fasting during pregnancy;
emotional and physical trauma suffered by the child during childhood;
birth trauma;
poor environmental conditions;
drug and alcohol use;
social isolation;
intrauterine development disorder.

Who is more likely to get sick?

Many people, completely unreasonably, believe that the disease occurs as a result of:

only hereditary factor;
transmitted through generations, that is, from grandfathers to grandchildren;
the presence of female patients (that is, schizophrenia is transmitted through the female line);
the presence of men suffering from schizophrenia (only from man to man).

In fact, such statements are devoid of any scientific basis. The risk of the disease equal to one percent remains in people with completely normal heredity.

If a half-brother or sister has pathology, the probability increases to six percent. The same figures can be cited when it comes to parents.

The highest probability, almost 50%, occurs when one of the parents and both representatives of the older generation - grandparents - are sick.

The same percentage is the possibility of developing the disease in an identical twin when schizophrenia is diagnosed in the second.

Despite the fact that the probability of illness in the presence of several patients in the family remains quite high, these are still not the most terrible indicators.

If we compare the data with a hereditary predisposition to cancer or diabetes, we can understand that they are still much lower.

Features of the examination

For various hereditary pathologies, conducting research is not particularly difficult. This happens because a specific gene is responsible for the development of a particular disease.

In schizophrenia, this is difficult to do, since this occurs at the level of different genes, and in each patient completely different mutations may be responsible for this.

Experts note that, according to their observations, the degree of likelihood of mental disorders in a child depends on the number of altered genes. For this reason, one should not believe stories that the disease is transmitted through the male or female line.

In fact, even experienced specialists cannot know which gene is responsible for schizophrenia in each specific case.

Most types of mental disorders develop quite slowly, and the diagnosis is made several years after the appearance of the first nonspecific symptoms.

Exercise from a psychological test for schizophrenia

Conclusions

We can safely say that the hereditary form of schizophrenia develops as a result of the general interaction of several genes, which, when combined, cause a predisposition to this pathology.

Schizopherenia and hereditary theory

Schizophrenia is a hereditary disease of endogenous nature, which is characterized by a number of negative and positive symptoms and progressive personality changes. From this definition it is clear that pathology is inherited and occurs over a long period of time, passing through certain stages of its development. Its negative symptoms include the patient’s pre-existing signs that “fall out” from the spectrum of his mental activity. Positive symptoms are new signs, which may include, for example, hallucinations or delusional disorders.

It is worth noting that there are no significant differences between ordinary and hereditary schizophrenia. In the latter case, the clinical picture is less pronounced. Patients experience disturbances in perception, speech and thinking; as the disease progresses, outbursts of aggression may occur as a reaction to the most minor stimuli. As a rule, a disease that is inherited is more difficult to treat.

In general, the issue of the heredity of mental illness is quite acute today. As for such a pathology as schizophrenia, heredity really plays a key role here. History knows of cases when there were entire “crazy” families. It is not surprising that people whose relatives have been diagnosed with schizophrenia are tormented by the question of whether the disease is inherited or not. It should be emphasized here that, according to many scientists, people who do not have a genetic predisposition to the disease, under certain unfavorable circumstances, have no less risk of developing schizophrenia than those in whose families there have already been episodes of pathology.

Features of genetic mutations

Since hereditary schizophrenia is one of the most common mental illnesses, a lot of scientific research has been conducted to study potential mutations caused by the absence or, conversely, the presence of specific mutation genes. It is believed that they increase the risk of developing the disease. However, it was also found that these genes are local, which suggests that the available statistics cannot claim to be 100% accurate.

Most genetic diseases are characterized by a very simple type of inheritance: there is one “wrong” gene, which is either inherited by descendants or not. Other diseases have several such genes. As for a pathology such as schizophrenia, there is no exact data on the mechanism of its development, but there are studies whose results indicated that seventy-four genes may be involved in its occurrence.

Scheme of hereditary transmission of the disease

In one of the latest studies on this topic, scientists studied the genomes of several thousand patients diagnosed with schizophrenia. The main difficulty in conducting this experiment was that the patients had different sets of genes, but most of the defective genes did have some common features, and their functions related to the regulation of the development process and subsequent brain activity. Thus, the more of these “wrong” genes a particular person has, the higher the likelihood that he will develop a mental illness.

Such a low reliability of the results obtained can be associated with the problems of taking into account many genetic factors, as well as environmental factors that have a certain impact on patients. We can only say that if the disease schizophrenia is inherited, it is in its most rudimentary state, being simply an innate predisposition to mental disorder. Whether the disease will occur in a particular person in the future or not will depend on many other factors, in particular psychological, stress, biological, etc.

Statistics data

Despite the fact that there is no conclusive evidence that schizophrenia is a genetically determined disease, there is some information that allows us to confirm the existing hypothesis. If a person without “bad” heredity has a risk of getting sick of approximately 1%, then if there is a genetic predisposition, these numbers increase:

up to 2% if schizophrenia is found in an uncle or aunt, cousin or sister;
up to 5% if the disease is detected in one of the parents or grandparents;
up to 6% if a half-sibling is sick and up to 9% for siblings;
up to 12% if the disease is diagnosed in one of the parents and in a grandparent;
up to 18% is the risk of the disease for fraternal twins, while for identical twins this figure rises to 46%;
Also, 46% is the risk of developing the disease in the case when one of the parents is sick, as well as both of his parents, that is, both grandparents.

Despite these indicators, it should be remembered that not only genetic, but also many other factors influence a person’s mental state. In addition, even with fairly high risks, there is always the possibility of the birth of completely healthy offspring.

Diagnostics

When it comes to genetic pathologies, most people are primarily concerned about their own offspring. The peculiarity of hereditary diseases, and in particular schizophrenia, is that it is almost impossible to predict with a high degree of probability whether the disease will be transmitted or not. If one or both future parents have cases of this disease in the family, it makes sense to consult with a geneticist when planning a pregnancy, as well as conduct an intrauterine diagnostic examination of the fetus.

Since hereditary schizophrenia has rather unexpressed symptoms, it can be very difficult to diagnose it at the initial stage; in most cases, the diagnosis is made several years after the appearance of the first pathological signs. When making a diagnosis, the leading role is given to the psychological examination of patients and the study of their clinical manifestations.

Returning to the question of whether schizophrenia is inherited or not, we can say that there is no exact answer yet. The exact mechanism of development of the pathological condition is still unknown. There is no sufficient evidence to say that schizophrenia is a completely genetically determined disease, just as it cannot be said that its occurrence is the result of brain damage in each particular case.

Today, human genetic capabilities continue to be actively studied, and scientists and researchers around the world are gradually approaching an understanding of the mechanism of the occurrence of hereditary schizophrenia. Specific gene mutations were discovered that increase the risk of developing the disease by more than tenfold, and it was also found that under certain conditions the risk of developing pathology in the presence of a hereditary predisposition can reach more than 70%. However, these figures remain rather arbitrary. We can only say with confidence that scientific progress in this area will determine what pharmacological therapy for schizophrenia will become in the near future.

Schizophrenia is a hereditary disease, methods of diagnosis and treatment

The transmission of mental illness by inheritance is far from an idle issue. Everyone wants themselves, their loved ones and their children to be healthy physically and mentally.

What should you do if among your relatives or the relatives of your significant other there are patients with schizophrenia?

There was a time when there was talk that scientists had found 72 genes for schizophrenia. Several years have passed since then and the research data have not been confirmed.

Since the origin of the disease is unknown, medical scientists have identified several hypotheses for the occurrence of schizophrenia:

Genetic – in twin children, as well as in families where parents suffer from schizophrenia, more frequent manifestations of the disease are observed.
Dopamine: human mental activity depends on the production and interaction of the main mediators, serotonin, dopamine and melatonin. In schizophrenia, there is increased stimulation of dopamine receptors in the limbic region of the brain. However, this causes the manifestation of productive symptoms, in the form of delusions and hallucinations, and does not in any way affect the development of negative symptoms - apatho-abulic syndrome: decreased will and emotions. ;
Constitutional is a set of psychophysiological characteristics of a person: gynecomorphic men and pyknic-type women are most often found among patients with schizophrenia. Patients with morphological dysplasia are considered to be less responsive to treatment.
The infectious theory of the origin of schizophrenia is currently of more historical interest than it has any basis. Previously, it was believed that staphylococcus, streptococcus, tuberculosis and E. coli, as well as chronic viral diseases reduce human immunity, which is supposedly one of the factors in the development of schizophrenia.
Neurogenetic: a mismatch between the work of the right and left hemispheres due to a defect in the corpus callosum, as well as a violation of the fronto-cerebellar connections leads to the development of productive manifestations of the disease.
Psychoanalytic theory explains the appearance of schizophrenia in families with a cold and cruel mother, an oppressive father, a lack of warm relationships among family members, or their manifestation of opposing emotions to the same behavior of the child.
Environmental – mutagenic influence of unfavorable environmental factors and lack of vitamins during fetal development.
Evolutionary: increasing the intelligence of people and increasing technocratic development in society.

The likelihood of developing schizophrenia

The probability of developing schizophrenia in persons who do not have a sick relative is 1%. And for a person with a family history of schizophrenia, this percentage is distributed as follows:

one of the parents is sick - the risk of getting sick will be 6%,
father or mother is sick, as well as grandparents - 3%,
a brother or sister suffers from schizophrenia – 9%,
either the grandfather or grandmother is sick - the risk is 5%,
when a cousin (brother) or aunt (uncle) gets sick, then the risk of disease is 2%,
if only the nephew is sick, the probability of schizophrenia will be 6%.

Schizophrenia is hereditary in the female or male line

Hereditary schizophrenia

We help patients not only with inpatient treatment, but also try to provide further outpatient and socio-psychological rehabilitation, telephone number of the Preobrazhenie clinic.

Is schizophrenia inherited?

Schizophrenia is a psychosis of an endogenous nature, a mental disorder that is particularly severe.

Reasons

brain injuries - both birth and postpartum;
serious emotional trauma suffered at an early age;
environmental factors;
severe shocks and stress;
alcohol and drug addiction;
anomalies of intrauterine development;
social isolation of the individual.

The causes of this disease themselves are divided into:

biological (viral infectious diseases suffered by the mother during the process of bearing a child; similar diseases suffered by the child in early childhood; genetic and immune factors; toxic damage from certain substances);
psychological (until the manifestation of the disease, a person is closed, immersed in his inner world, has difficulty communicating with others, is prone to lengthy reasoning, has difficulty trying to formulate a thought, is characterized by increased sensitivity to stressful situations, is sloppy, passive, stubborn and suspicious, pathological vulnerable);
social (urbanization, stress, characteristics of family relationships).

The connection between schizophrenia and heredity

detection of schizophrenia in one of the identical twins (49%);
diagnosis of the disease in one of the parents or both representatives of the older generation (47%);
detection of pathology in one of the fraternal twins (17%);
detection of schizophrenia in one of the parents and at the same time in someone from the older generation (12%);
detection of the disease in an older brother or sister (9%);
detection of the disease in one of the parents (6%);
diagnosing schizophrenia in a nephew or niece (4%);
manifestations of the disease in aunts, uncles, and cousins (2%).

Thus, we can come to the conclusion that schizophrenia is not necessarily inherited, and the chance of giving birth to a healthy child is quite high.

When planning a pregnancy, you should consult a geneticist.

Diagnostic methods

So, hereditary schizophrenia arises as a result of the mutual influence of a group of genes on each other, which develop in a special way and cause a predisposition to the disease.

Is schizophrenia inherited or not?

The process of studying the causes of the development of schizophrenia has continued for more than a century, but not a single specific causative factor has been discovered and a unified theory of the development of the disease has not been developed. Today, the therapies available in the medical arsenal can alleviate many of the symptoms of the disease, but in most cases, patients are forced to live with residual symptoms for the rest of their lives. Scientists from all over the world are developing more effective drugs and using the latest and most modern tools and research methods to find the cause of the disease.

Schizophrenia is a severe chronic mental disorder leading to disability and known to mankind throughout its historical development.

Since the cause of the disease has not been precisely established, it is difficult to say for sure whether schizophrenia is a hereditary or acquired disease. There are research results that indicate that schizophrenia is inherited in a certain percentage of cases.

Today, the disease is regarded as a multifactorial disease caused by the interaction of endogenous (internal) and exogenous (external or environmental) causes. That is, heredity (genetic factors) alone is not enough for the development of this mental disorder; the effect of environmental factors on the body is also necessary. This is the so-called epigenetic theory of the development of schizophrenia.

The diagram below shows the probable process of development of schizophrenia.

There may not be factors of brain damage, including neuroinfection, for schizophrenia to develop

Human genes are localized on 23 pairs of chromosomes. The latter are located in the nucleus of every human cell. Each person inherits two copies of each gene, one from each parent. Certain genes are thought to be associated with an increased risk of developing the disease. Given the presence of genetic prerequisites, according to scientists, it is unlikely that genes themselves can cause the development of the disease. To date, it is still impossible to accurately predict who will get the disease based on genetic testing.

It is known that the age of parents (over 35 years) plays an important role in the development of not only schizophrenia, but also other diseases associated with genome damage. This is explained by the fact that gene defects accumulate with age, and this can affect the health of the unborn child.

According to statistics, this disease affects about 1% of the adult population. It has been found that people whose immediate family members (a parent, sibling) or second-degree relatives (aunts, uncles, grandparents, or cousins) have schizophrenia have a much higher risk of developing the disease than others. people. In a pair of identical twins, where one has schizophrenia, the second has the highest risk of developing the disease: 40-65%.

Men and women have the same chance of developing this psychological illness throughout their lives. Although the disease begins much earlier in men than in women.

One study found that the likelihood of developing schizophrenia varies among different population groups:

general population (no sick relatives) - 1%;
children (one parent is sick) - 12%;
children (both parents are sick) - 35-46%;
grandchildren (if grandparents are sick) - 5%;
siblings (sisters or brothers are sick) - up to 12%;
fraternal twins (one of the twins is sick) - 9-26%;
identical twins (one of the twins is sick) - 35-45%.

That is, the predisposition to this mental illness is transmitted from grandfather/grandmother to grandson than from father/mother to son or daughter.

If the mother in a family has schizophrenia, then the likelihood of children getting sick with this pathology is 5 times higher than if the father was sick. Thus, schizophrenia is transmitted through the female line much more often than from father to child.

Is schizophrenia hereditary or not?

Heredity as a cause of the disease

Statistics of the “genetic theory”

To date, psychiatry has accumulated enough information to come to certain conclusions on the issue of how schizophrenia is inherited.

The highest rates were recorded in pairs of identical (monozygotic) twins. They have completely identical genes. If one of them gets sick, then the second has a 48% risk of developing pathology.

Much attention from the medical community was attracted by a case described in works on psychiatry (monograph by D. Rosenthal et al.) back in the 70s of the 20th century. The father of four identical twin girls suffered from mental disorders. The girls developed normally, studied and communicated with peers. One of them did not graduate from the educational institution, but three completed their studies at school successfully. However, at the ages of 20–23 years, schizoid mental disorders began to develop in all sisters. The most severe form - catatonic (with characteristic symptoms in the form of psychomotor disorders) was recorded in a girl who had not completed school. Of course, in such striking cases, psychiatrists simply do not have doubts whether this is a hereditary disease or an acquired one.

9%, if your sibling fell victim to a mental illness, but no other similar abnormalities were found in the closest relatives.

From 2 to 6% the risk will be for someone in whose family there is only one case of pathology: one of your parents, a half-brother or sister, an uncle or aunt, one of your nephews, etc.

Which line is more likely to have bad heredity?

About other hypotheses of the occurrence of pathology

Along with heredity, among the main reasons for the development of the disease, doctors also name:

neurochemical disorders;
alcoholism and drug addiction;
a traumatic experience experienced by a person;
maternal illness during pregnancy, etc.

Obviously, with a combination of bad heredity and other provoking factors, the risk of getting sick will be higher.

Additional information. Psychotherapist, Candidate of Medical Sciences Galushchak A. talks in more detail about the causes of pathology, its development and possible prevention.

What to do if you are at risk?

If you know for sure that you have an innate predisposition to mental disorders, you need to take this information seriously. It is easier to prevent any disease than to cure it.

Simple preventative measures are within the capabilities of anyone:

Lead a healthy lifestyle, give up alcohol and other bad habits, choose the optimal regime of physical activity and rest for yourself, control your diet.
Regularly see a psychologist, consult a doctor promptly if you have any unfavorable symptoms, and do not self-medicate.
Pay special attention to your mental well-being: avoid stressful situations and excessive stress.

Is the schizophrenia gene passed on to children?

The existence of genetic factors in the occurrence of schizophrenia is beyond doubt, but not in the sense of certain carrier genes.

Schizophrenia is inherited only when the life path of an individual, her fate, prepares a kind of soil for the development of the disease.

Unsuccessful love, life's misfortunes and psycho-emotional traumas lead to a person moving away from unbearable reality into the world of dreams and fantasies.

Read about the symptoms of the hebephrenic form of schizophrenia in our article.

What kind of disease is this?

Schizophrenia is a chronic progressive disease that includes a complex of psychoses that arise as a result of internal causes not related to somatic diseases (brain tumor, alcoholism, drug addiction, encephalitis, etc.).

As a result of the disease, a pathological change in personality occurs with a violation of mental processes, expressed by the following signs:

Gradual loss of social contacts, leading to isolation of the patient.
Emotional impoverishment.
Thinking disorders: empty, fruitless verbosity, judgments devoid of common sense, symbolism.
Internal contradictions. Mental processes occurring in the patient’s consciousness are divided into “his own” and external, that is, those that do not belong to him.

Associated symptoms include the appearance of delusional ideas, hallucinatory and illusory disorders, and depressive syndrome.

The course of schizophrenia is characterized by two phases: acute and chronic. In the chronic stage, patients become apathetic: mentally and physically devastated. The acute phase is characterized by a pronounced mental syndrome, which includes a complex of symptom-phenomena:

the ability to hear one's own thoughts;
voices commenting on the patient’s actions;
perception of voices in the form of dialogue;
own aspirations are realized under external influence;
experiences of impact on your body;
someone takes away his thoughts from the patient;
others can read the patient's thoughts.

Schizophrenia is diagnosed if the patient has a combination of manic-depressive disorders, paranoid and hallucinatory symptoms.

Who can get sick?

The disease can begin at any age, however, most often the onset of schizophrenia occurs at the age of 20–25 years.

According to statistics, the incidence is the same in men and women, but in males the disease develops much earlier and can begin in adolescence.

In females, the disease is more acute and is expressed by vivid, affective symptoms.

According to statistics, 2% of the world's population suffers from schizophrenia. There is currently no unified theory of the cause of the disease.

Congenital or acquired?

Is this disease hereditary or not? To this day there is no single theory of the origin of schizophrenia.

Researchers have put forward many hypotheses about the mechanism of development of the disease, and each of them has its own confirmation, however, none of these concepts fully explains the origin of the disease.

Among the many theories of the origin of schizophrenia are:

The role of heredity. A family predisposition to schizophrenia has been scientifically proven. However, in 20% of cases the disease first appears in a family in which hereditary burden has not been proven.
Neurological factors. In patients with schizophrenia, various pathologies of the central nervous system were identified, caused by damage to brain tissue by autoimmune or toxic processes in the perinatal period or in the first years of life. Interestingly, similar central nervous system disorders were found in mentally healthy relatives of a patient with schizophrenia.

Thus, it has been proven that schizophrenia is predominantly a genetic disease associated with various neurochemical and neuroanatomical lesions of the nervous system.

However, “activation” of the disease occurs under the influence of internal and environmental factors:

psycho-emotional trauma;
family dynamic aspects: incorrect distribution of roles, overprotective mother, etc.;
cognitive impairment (impaired attention, memory);
impairment of social interaction;

Based on the above, we can conclude that schizophrenia is a multifactorial disease of a polygenic nature. In this case, the genetic predisposition in a certain patient is realized only through the interaction of internal and external factors.

How to distinguish sluggish schizophrenia from neurosis? Find out the answer right now.

Which gene is responsible for the disease?

Several decades ago, scientists tried to identify the gene responsible for schizophrenia. The dopamine hypothesis has been widely promoted, suggesting dysregulation of dopamine in patients. However, this theory has been scientifically refuted.

Today, researchers are inclined to believe that the basis of the disease is a violation of the impulse transmission of many genes.

Inheritance - male or female?

There is an opinion that schizophrenia is transmitted more often through the male line. These conclusions are based on the mechanisms of manifestation of the disease:

In men, the disease manifests itself at an earlier age than in women. Sometimes the first manifestations of schizophrenia in women can begin only during menopause.
Schizophrenia in a genetic carrier manifests itself under the influence of some trigger mechanism. Men experience psycho-emotional trauma much more deeply than women, which causes them to develop the disease more often.

In fact, if a mother in a family has schizophrenia, then children get sick 5 times more often than if the father was sick.

Statistical data on the presence of genetic predisposition

Genetic studies have proven the role of heredity in the development of schizophrenia.

If the disease is present in both parents, then the risk of the disease is 50%.

If one of the parents has the disease, the probability of its occurrence in the child is reduced to 5–10%.

Studies using the twin method have shown that the probability of inheriting the disease in both identical twins is 50%, in fraternal twins this figure decreases to 13%.

To a greater extent, what is inherited is not schizophrenia itself, but a predisposition to the disease, the implementation of which depends on many factors, including trigger mechanisms.

Testing for multiple personality disorder can be taken on our website.

How to find out the probability in your family?

The risk of developing schizophrenia in a person with unaffected genetics is 1%. If one of the parents is sick in the family, then the probability of inheritance is 5–10%.

If the disease manifests itself in the mother, then the risk of the disease increases significantly, especially in a male child.

The chance of developing the disease is 50% if both parents are affected. If there were grandparents with schizophrenia in the family, then the risk of the disease for a grandson is 5%.

If the disease is detected in siblings, the likelihood of schizophrenia will be 6–12%.

Through what line is schizophrenia transmitted? Find out about it in the video:

How is inherited - diagram

The likelihood of inheriting schizophrenia from relatives depends on the degree of relationship.

How is schizophrenia transmitted: is there a hereditary gene?

People with schizophrenia have impaired brain function, and they perceive reality to one degree or another distorted.

Of the 300 types of disease, 30% of cases are treatable, and patients can live a full life. But the patient’s family members cannot help but be concerned about the question of whether schizophrenia is inherited and whether it will manifest itself in future generations.

According to WHO, 21 million people in the world have this diagnosis.

Today, the nature of the origin of schizophrenia has not been clearly elucidated, as has the exact mechanism of inheritance, but hundreds of scientists from dozens of organizations around the world are working together to study its nature. Their successes and discoveries give hope to patients.

Causes of schizophrenia

To a large extent, the disease is considered hereditary. It is passed on to direct descendants and through generations, so it is often found in families. In addition to the genetic causes of schizophrenia, there may be the following:

environmental factors: prolonged or premature labor, a viral infection in infancy that attacked certain areas of the brain;
stress experienced in childhood, caused by early loss of parents, physical or sexual abuse.

Hereditary schizophrenia is the most difficult to diagnose; in most cases, an accurate diagnosis is made after several years from the onset of its first symptoms.

Emerging theories about the causes of schizophrenic disorders concern the process of brain formation, starting from the earliest stages of fetal development, when millions of neurons migrate to different areas at its inception.

Deviation from the norm can be caused by hormonal imbalance, maternal fasting in the 1st trimester of pregnancy, an error in genetic coding and other factors.

In people with a traumatic brain injury, the risk of developing schizophrenia increases depending on the area of the brain injury.

The Royal College of Surgeons in Dublin compared the results of studies of 2 groups of people: those who suffered from traumatic brain injuries and those who did not. All participants had blood relatives diagnosed with schizophrenia.

As a result, it was found that head injury increases the risk of the disease by 2.8 times. However, this connection is not yet considered to be conclusively proven.

Inherited schizophrenia - likelihood of occurrence

After the advent of genetic research methods, they began to be applied to the study of mental disorders. The difficulty in researching schizophrenia is due to the fact that there is no clear pattern of inheritance of the disease.

Analysis of general indicators revealed that genetics does not influence all cases of schizophrenia as a hereditary disease.

It is genetically determined, and those who have relatives with this diagnosis may be predisposed to it. Whether the disease manifests itself or not depends on many other factors.

Figures of hereditary schizophrenia

In persons who do not have a sick relative, the probability of the disease is 1%. The disease is transmitted in 70% of cases. However, psychiatrists in different countries have their own data on how it is inherited.

The likelihood of developing schizophrenia during life depends on the degree of relationship with the patient and is as follows:

if 1 of the parents is sick - 13%;
both parents are sick - up to 40%;
if a grandmother or grandfather is sick - 13%;
for identical (fraternal) twins - 49%;
if a fraternal twin is sick - 17%;
for siblings - 10%.

The highest probability, almost 50%, occurs when parents and grandparents are sick. If you are a second-degree relative - an uncle, aunt, nephew or grandson of a patient, the probability of getting sick is below 6%, and for second cousins - up to 1.5%.

These numbers are a possible risk. In most cases, the disease manifests itself in late adolescence and in young people at the age of 20, after 45 years it is extremely rare.

Is there a gene for schizophrenia?

In 2014, scientists at the Massachusetts Institute of Technology and Harvard University identified more than 100 regions of the human genome associated with this disease. The research results were published in the journal Nature in early 2016.

Scientists have created a molecular method for studying common gene mutations and studied data from 65 thousand patients from 30 countries, of which 29 thousand suffer from schizophrenia, as well as 700 post-mortem brain samples. Research was also carried out using laboratory mice.

As a result, it was found that people with a genetic predisposition to schizophrenia are characterized by 1 of the variants of chromosome 4 - component C4, with excessive expression.

C4 is responsible for the production of protein, is part of the immune system, and, as the authors of the work found, is responsible for the heredity of schizophrenia.

Until the onset of puberty, the density of synapses (connections between neurons) is maintained at the highest possible level. From the moment of puberty their elimination begins. This happens to all people and is a normal process.

But with abnormal expression of C4, too many synapses are removed at the time of brain formation, which causes the first manifestations of symptoms of schizophrenia - hallucinations and a decrease in the brightness of emotions.

Most experts believe that this study opens up vast possibilities for studying the disease, and C4 is a small piece of a larger puzzle that has yet to be fully solved.

This may take scientists decades of work.

So is it hereditary or not?

If the C4 gene is dominant, then why, if one of the parents is sick, the probability of having a child with schizophrenia is not 100%?

Numerous publications often prove the opposite: that genes are to blame, and the disease is inherited or not - and then they prioritize external influences.

No one can say for sure that a person with genetic defects will get sick, and vice versa. Only one thing can be said for sure: the more defective genes, the higher the risk of schizophrenia.

There is evidence that if a woman has the flu during pregnancy, it is not the virus, but an excessive reaction of her body with the release of interleukin-8 that causes mental disorders in the child.

However, not all women with an increase in the amount of IL-8 give birth to sick offspring, even if the pregnant women themselves are predisposed to the development of mental disorders.

It is not the disease itself that is inherited, but the pattern of its metabolic processes. Disturbances can occur not in 1, but in 3 genes that interact with each other, and in total about 30 mutations associated with schizophrenia have been identified.

The disease is not transmitted to all relatives, but everyone has a predisposition to it.

The risk of pathology increases with constant stress, alcoholism and drug addiction.

Is schizophrenia transmitted through the male or female line?

The disease is more common in men, and it begins to manifest itself earlier and is characterized by a greater number of symptoms and more severe forms.

But practicing psychiatrists argue that schizophrenia is inherited on both the maternal and paternal lines.

It has been established that in 20-30% of adult patients the structure of the brain has the following anomalies:

the size of the lateral ventricles is increased;
reduced hippocampal size;
the amount of gray matter in the frontal lobe is reduced.

Scientists from ChapelHill University in North Carolina (USA), studying newborns born to sick women, found that boys had larger-than-average brains and lateral ventricles, indicating a predisposition to schizophrenia.

No anatomical abnormalities of the brain were identified in girls.

And a group of Australian scientists led by Dr. Hong Lee, having analyzed the genetic data of more than 12 thousand women, found that as the mother’s age increases (over 35 years), the risk of mental disorders in her unborn child increases.

Statements about heredity through the female line, through the male line, or exclusively through generations are incorrect. In most cases, the set of chromosomes is not predictable.

Is it possible to find out about the disease before the baby is born?

This question is important for the expectant mother if one of her relatives or her husband’s family suffers from schizophrenia.

Before planning a child, it is better to consult a psychiatrist and geneticist, who will conduct an examination and determine the most favorable period for conception and pregnancy.

Experts object if both spouses are sick, in which case schizophrenia is inherited in 46% of cases; in addition, pregnancy, childbirth and the postpartum period are a large physical, psychological and hormonal load on a woman’s body.

Researchers at Mount Sinai School of Medicine in New York have found evidence that it is possible to genetically detect schizophrenia before birth in those children who are at high risk of inheriting it.

They found that during embryonic development, microRNA molecules that control hundreds of genes associated with schizophrenia are expressed, but only weakly in one group.

Therefore, some structures in the brain will be connected to other structures in an abnormal way, which increases the likelihood of schizophrenia.