Modern physiologists have advanced far enough in the study of the neurobiology of schizophrenia. But they have not yet succeeded in identifying the causes and understanding the essence of this pathology. The etiology and pathogenesis of schizophrenia remain hidden from us. But over the years of research on this topic, a huge amount of information has been formed. In the article, we will briefly describe some theories and models of schizophrenia that explain its causes and mechanisms of development.

pathogenesis of schizophrenia

Formulation Of The Problem

Schizophrenia is an endogenous mental illness of a polymorphic type that affects thinking and causes the breakdown of emotional reactions. With its development, a person inadequately perceives himself and/or the surrounding reality. The unfavorable course of the disease can lead to the complete withdrawal of the patient into his fantasies, as a result of which he will no longer be interested in work, hobbies, and relatives.

The main problem of schizophrenia is unclear etiopathogenesis. First, science does not know the exact causes of the development of this disease. Scientists can look into the brain of a sick and healthy person with the help of modern diagnostic devices, but they are not able to describe the process of the emergence of psychopathology. Researchers have only theories, experimental results, and specific clinical cases at their disposal.

Secondly, schizophrenia is a very unpredictable disease, the development of which is almost impossible to predict. It manifests itself in a wide variety of forms. In some people, it progresses for years, and asymptomatically, while in others it causes personality disintegration in just a few months or a year.

Some patients experience only a limited number of symptoms of the disease in their lives, while a number of patients suffer from dozens of symptoms. Some have only one seizure in their entire lives, while others have flare-ups every few months.

All this complicates the treatment. If it were possible to find out the exact mechanism of the onset of schizophrenia, it would be easier to get rid of it. In the meantime, a person who has been diagnosed with this diagnosis is doomed to be a schizophrenic all his life. He only has a chance to prolong remission, but he will not be able to completely cure the disorder.

Schizophrenia develops in 1 out of 100 people, but in different forms.

There are a lot of theories and models of schizophrenia that are designed to explain its causes – genetic, pathophysiological, cognitive, dopamine, social, psychological, etc. Let’s consider some of them in more detail.



The genetic factor has long been considered decisive in the development of schizophrenia. This is not surprising, since numerous studies confirm the hereditary theory. Some of them were related to the distinction between the influence of the family and the genetic burden of the disease.

Scientists compared the risk of schizophrenia in people from two groups. The first included children whose parents have schizophrenia, but who are brought up in healthy families. The second was born to healthy adults but was raised in a foster family of people with schizophrenic disorders.

Subsequently, it turned out that the likelihood of developing schizophrenia increases if the biological parents have it, and not the adoptive ones. This made it possible to increase the importance of the genetic factor and reduce the role of the social one.

If a child has both parents with schizophrenia, then the risk of developing it in him is approximately 50%.

However, it is difficult to call such studies exhaustive. Mental disorders, indeed, are more likely to develop in those people whose relatives had similar pathologies. The closer the degree of relationship, the higher the likelihood of schizophrenia. But, firstly, the gene for this disease has not been identified, and secondly, about 10% of schizophrenic patients do not have a genetic predisposition to this disease.


Neurotransmitter Theories

Neurotransmitters, or neurotransmitters, are biologically active substances through which brain cells (neurons) communicate with each other. Among them are dopamine, serotonin, norepinephrine, etc. Neurotransmitter theories of the origin of schizophrenia are very popular today. This is also easily explained since the pathology is treated with neuroleptics – antipsychotic drugs that normalize the level of neurotransmitters.

There are two main theories associated with neurotransmitters – dopamine and serotonin. The first is based on the effect on brain receptors of dopamine, a hormone that forms attitudes, plays an important role in motivation, and also brings a feeling of pleasure, calmness, and joy.

It was found that during exacerbation of schizophrenia, there is an increased production of dopamine. This leads to hyperstimulation of nerve cells that send too many impulses to the brain. As a result, a person develops delusions, catatonia, or hallucinations. Antipsychotics that reduce dopamine levels help to stop these symptoms.

During the negative phase of schizophrenia, when the patient suffers from apathy and signs of depression, little joy hormone is released, which is usually compensated with antidepressants.

The principle of serotonin and norepinephrine theories is approximately the same. The newest antipsychotics affect not only dopamine but also other types of brain receptors, allowing you to quickly and effectively remove the main symptoms of the active phase of schizophrenia.


Psychological Theory

Psychological problems are usually considered the main triggers that can become an impetus for the development of schizophrenia. Simply put, they include a person at risk for this disease. Among these problems are various stressful situations and traumas, including sexual and physical abuse, despotic upbringing, etc.

Studies show that people with schizophrenia are more emotionally responsive to stress, tend to exaggerate danger, and also see threats where there are none. For this reason, much attention is paid to psychological counseling during the treatment of psychopathology. The patient is taught to cope with stress and life’s adversities, which allows for prolonging remission and prevention of exacerbation.

The psychological theory is based on observations of patients who already have a diagnosis, so the etiology and pathogenesis of the disease in this case still remain undisclosed. Millions of people live in difficult conditions, many of them are subjected to violence, but not everyone develops schizophrenia. Moreover, most of them, even having psychological problems and complexes, remain mentally healthy.


Social Factors

They are also considered triggers. In this case, we are talking about loneliness, isolation, and frequent changes of residence. Studies also show that urban residents, especially in large cities, suffer from schizophrenia more often than provincials. Other social factors include unemployment, low living standards, poor living conditions, social exclusion, and so on.

It is also worth mentioning alcoholism and drug addiction, which are often associated with mental disorders. However, there is no direct link between schizophrenia and psychoactive substances in terms of a causal component.

Schizophrenics often seek salvation in smoking, alcohol, and drugs, but this does not mean that such drugs provoke the disease. They can only cause another attack with an already existing pathology.


Dysontogenetic Theory

The dysontogenetic theory is based on MRI readings. Thanks to this technique, it was possible to identify structural disorders in the brain of a schizophrenic. In particular, such patients have an increase in the lateral ventricle and atrophy of the medial temporal lobes, hippocampus, tonsils, and superior temporal gyrus. Also, all people with schizophrenia have a significant decrease in gray matter volume.

However, the exact causes of such violations are unknown. They can be caused by both injuries and infections or poisoning. There may be other factors that have yet to be discovered. In general, this theory, although interesting and working, does not explain the principle of the development of schizophrenia.


Cognitive Theory

Cognitive theory has something in common with psychological and biological. Its essence is as follows: a person experiences strange sensations that are the result of the unusual work of his brain. He perceives the world around him differently and interprets it incorrectly. He tries to understand himself and know his feelings, tells about them to relatives and friends who do not understand him and goes inside himself. If a person begins to hear voices, then they laugh at him or call him crazy. This leads to the development of delusions of persecution, etc.

This theory, like many others that were not considered in the article, including psychoanalytic, is not applied in practice, as it is considered outdated. It cannot explain the mechanism of the onset of schizophrenia in the same detail as it is done with the help of genetic and instrumental research methods.

The question of the etiology of schizophrenia remains open. Most likely, as technology develops, scientists will be able to penetrate the mystery of this disease and unravel it. If this succeeds, then schizophrenics will have a chance to recover from this terrible disease forever.