Modern physiologists have advanced far enough in the study of the neurobiology of schizophrenia. But they have not yet succeeded in revealing the causes and understanding the essence of this pathology. The etiology and pathogenesis of schizophrenia remain hidden from us. But after many years of research on this subject, a huge amount of information has been formed. Let us briefly describe some theories and models of schizophrenia in this article, explaining its causes and development mechanisms.


pathogenesis of schizophrenia



Schizophrenia is an endogenous mental illness of the polymorphic type that affects thinking and causes a breakdown of emotional reactions. When it develops, the person perceives themself and the surrounding reality inadequately. The adverse progression of the disease can lead to a complete withdrawal of the patient into his fantasies, as a result of which he ceases to be interested in his work, hobbies, and relatives.

The main problem with schizophrenia is the unclear etiopathogenesis. First, science does not know the exact causes of the disease. Scientists can look into the brain of a sick and a healthy person with modern diagnostic instruments but cannot describe the process of the birth 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 virtually impossible to predict. It comes in many different forms. For some people, it progresses for years and is symptomless, while for others, it causes disintegration of the personality in just a few months or a year.

Some patients experience only a limited number of symptoms in their lives, while several patients suffer from dozens of symptoms. Some have only one attack in their lifetime, while others have flare-ups every few months.

All this complicates treatment. Could elucidate the exact mechanism of the genesis of schizophrenia, it would be easier to get rid of it. In the meantime, a person diagnosed with schizophrenia is doomed to be schizophrenic. He only has a chance to extend remission but can not completely cure the disorder.

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

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



The genetic factor has long been considered a determinant in the development of schizophrenia. It is not surprising since numerous studies have supported the hereditary theory. They related some of them to the distinction between family influence and genetic aggravation of the disease.

Researchers compared the risk of schizophrenia in people from two different groups. The first included children whose parents had schizophrenia but were raised in healthy families. The second group included children born to healthy adults but raised in foster care by people with schizophrenia.

Subsequently, it turned out that the probability of developing schizophrenia increased if the biological parents had it, not the adoptive parents. It increased the genetic factor’s importance and decreased the social factor’s role.

If both parents have schizophrenia in a child, the risk of the child developing schizophrenia is about 50%.

However, it is difficult to call such studies exhaustive. Indeed, mental disorders more often develop in people whose relatives have similar pathologies—the nearer the degree of kinship, the greater the likelihood of schizophrenia. But, firstly, the gene for this disease has never been found, and secondly, about 10% of schizophrenic patients have no genetic predisposition to this disease.


Psychological theory

Neurotransmitters are biologically active substances through which brain cells (neurons) communicate with each other. They include dopamine, serotonin, norepinephrine, etc. Neurotransmitter theories of schizophrenia origin are very popular today. It 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 dopamine’s effect on the brain receptors – a hormone that shapes attitudes plays an important role in motivation and brings pleasure, calmness, and joy.

It has been found that when schizophrenia worsens, there is an increased production of dopamine. It leads to nerve cell hyperstimulation that sends too many impulses to the brain. As a result, the person develops delusions, catatonia, or hallucinations. Neuroleptics that reduce dopamine levels can treat these symptoms.

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

The principle of the serotonin and noradrenaline theories is roughly the same. The new neuroleptics affect not only dopamine receptors but also other types of receptors in the brain, allowing a faster and more effective elimination of the main symptoms of the active phase of schizophrenia.


Psychological Theory

Psychological problems are usually seen as the main triggers that can cause a person to develop schizophrenia. In simpler terms, they place a person at risk for the disease. Such problems include stressful situations and traumas, including sexual and physical abuse, oppressive parenting, etc.

Studies show that people with schizophrenia react more emotionally to stress, exaggerate danger, and see threats where there are none. For this reason, psychological counseling is emphasized in the treatment of psychopathology. The patient is taught to cope with stress and adversity, which prolongs remission and helps prevent exacerbations.

Psychological theory is based on observations of patients who already have a diagnosis, so the etiology and pathogenesis of the disease, in this case, remain undisclosed. Millions of people live in difficult conditions, many of whom are abused, but not all develop schizophrenia. Moreover, most remain mentally healthy, even having psychological problems and complications.


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, have schizophrenia more often than provincial residents. Other social factors include unemployment, low living standards, poor living conditions, social isolation, etc.

Here we should also mention alcoholism and drug addiction, often associated with mental disorders. However, there is no direct connection between schizophrenia and psychoactive drugs as far as the causal component is concerned.

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


Dissontogenetic Theory

The dysontogenetic theory is based on readings obtained with MRI. This technique made it possible to identify structural abnormalities in the schizophrenic brain. In particular, such patients have enlargement of the lateral ventricle and atrophy of the medial temporal lobes, hippocampus, amygdala, and superior temporal gyrus. Also, all people with schizophrenia significantly reduced gray matter volume.

At the same time, the exact causes of such abnormalities are unknown. Trauma, infections, or poisoning may cause them. Other factors, which have yet to be discovered, may also be involved. Though not uninteresting and working, this theory doesn’t explain the principle of schizophrenia development.


Cognitive theory

The cognitive theory echoes the psychological and biological theories. Its essence is the following: a person experiences strange sensations, which are a consequence of the unique 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 relatives and friends who don’t understand him and goes inside himself. If the person begins to hear voices, they laugh at him or call him crazy. It leads to the development of delusions of persecution, etc.

This theory, as well as many others not discussed in the article, including the psychoanalytic theory, is not applied in practice because it is considered outdated. It cannot explain the mechanism of the genesis of schizophrenia in as much detail as it does with genetic and instrumental research methods.

The question of the etiology of schizophrenia remains open. Most likely, as technology advances, scientists will be able to penetrate the mystery of this disease and unravel it. If this succeeds, people with schizophrenia will have a chance to be cured of this terrible disease forever.