Schizophrenia is referred to as a syndrome because there would be a constellation of symptoms and essentially different patients manifest with a range of different symptoms. There are criteria for the diagnosis and this would be assisting in categorizing the patients with different symptoms with a common diagnosis of schizophrenia.
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Image: “20150410” by nik gaffney. License: CC BY-SA 2.0


Schizophrenia is defined as a mental disorder where the essential relation between three aspects namely thought, emotion and behavior have been broken. This lead to the inappropriate action along with the withdrawal tendency from the society, the fantasy takes over the person along with the fragmented mental thought process. 

Epidemiology of Schizophrenia

There is a mild preponderance of the disease with the male when compared to that of the females (proposed mechanism: estrogen effect in the reduction of the dopamine). The intensity of the schizophrenia is also less severe in the female than in the men. It is estimated that the life expectancy of a person with schizophrenia is about 10—20 years less when compared to that of the general population.

One of the interesting findings is that the people with schizophrenia are more likely to have born in the season of winter. Although there occurs no difference in the occurrence of the disease among the various races, the disease is seen more among the people in the person in the twenties with the mid-twenties in the male and the late twenty in the female. 


Image: “Age-standardised disability-adjusted life year (DALY) rates from Schizophrenia by country (per 100,000 inhabitants).” by Lokal_Profil. License: CC BY-SA 2.5

Etiology of Schizophrenia

The cause of schizophrenia is not readily well delineated but some of the proposed causes include environmental and genetic factors.

Genetic factors

Though the genetic cause of the schizophrenia is not completely understood, there occur predisposition among the monozygotic (has shown up to 40 percent inheritance) and dizygotic twins. Some of the proposed genes include NOTCH4, Zinc finger protein 804A, Histone protein loci.

Environmental factors

The environmental factor includes affluent environment, the presence of childhood trauma, drug abuse (commonly abused drug include amphetamine, cocaine, alcohol), the untimely death of the parents, older parental age group etc.

The occurrence of schizophrenia is also linked with other prenatal infection (some of the infection which are proposed include that of Toxoplasma, chlamydia) and nutritional deficiency of the mother. The essential pathophysiology of how this infection leads to the schizophrenia is unknown. Certain autoimmune diseases such as non-gluten sensitive immune disorder of the gastrointestinal tract have an increase in the predisposition of causing schizophrenia.

Classification of Schizophrenia

The various types  of schizophrenia include:

  • Paranoid type in which hallucination of the auditory type and the delusions remain the cornerstone
  • Disorganised type also sometimes referred as hebephrenic schizophrenia
  • Catatonic type: In this, the patient essentially remains immobile in a particular place
  • Undifferentiated type: In this, though the symptoms of psychosis are present in the patient, the patient could not be classified in any of the 3 types mentioned above
  • Residual type: It is the type in which the symptoms intensity remains slow and does not qualify fully to fall into any other categories.
  • In addition, two other types mentioned according to the ICD-10 include
  • Simple schizophrenia in which no positive symptoms occur but a direct progression to that of a negative symptom
  • Post-schizophrenic depression in which the depression which occurs following schizophrenia is manifested along with a very low level of psychosis 

Pathophysiology of Schizophrenia

The causative role can be discussed under 3 broad heading namely. The genetic, environment and the neurotransmitter biology dysregulation. The increase in the level of the dopamine especially in the mesolimbic and the prefrontal region constitutes the neurotransmitter etiologies of the schizophrenia and. but the essential cause is still unknown. The other neurotransmitter such as serotonin and GABA might be involved in the causative role in the schizophrenia. 


Image: “Lobes that schizophrenia effects.” by BruceBlaus. License: CC BY-SA 4.0

Symptoms of Schizophrenia

The symptoms which characterizes schizophrenia include belief which is false, the confused thinking cum understanding about things, reduction in the engagement in various social activities as well as the expressions which are routinely shown in social behaviour by normal person, reduction in the motivation, seeing out things which are not really present and hearing the audios and voices again in the imagination.

The symptoms of schizophrenia can be classified into a positive, negative and cognitive symptom.

Positive symptoms

The positive psychotic symptoms include delusion of control, which basically means that the person believes that someone else is having a control over him and is responsible for his behavior (The word delusion itself means that holding a belief in spite of being argued with rational argument and reality).

The delusion of reference, which means that a person believes that someone else is referring to him which might not be the case. The characteristic example cited in the medical literature for the delusion of reference is a person seeing a TV anchor and referring that the TV anchor is speaking directly to him.

Other symptoms include disorganized speech, which means that the person just splits words but the entire group of words does not form meaning into sentences (known as word salad). In addition to that, the person would have auditory hallucination (a characteristic feature of schizophrenia). Visual, tactile, gustatory hallucination also seen in some person. In terms of behavior, it is seen that the schizophrenia patients would have a disorganized bizarre behavior without any purpose and there would be a reduction in the movement and responses (referred to as the catatonic behavior).

Negative symptoms

The negative symptom manifest as a decrease of emotions and an overall reduction in the interest shown by the person in the activities. Lack of experience of the pleasure in those things which generally impart a sense of pleasure in others is seen. This reduction of interest manifest as a poverty of speech known as a logic or reduction in the motivation known as avolition or responses which are appropriate to the situation known as avolition. It should be known that the negative symptoms impact the life of a person more when compared to that of a positive symptom and the negative symptom are associated with that of the poorer outcome and reduced alternatives of medicine available for treating.

Cognitive symptoms

These symptoms manifest as a reduction in the learning capacity, loss of memory (includes many types such as long term, working, verbative, episodic memory), reduction in understanding and comprehension of situations, difficulty in the speed with which information is processed. 

Progression and Special Forms of Schizophrenia

There are three phases of schizophrenia namely the prodromal phase, the active phase, and the residual phase.

  1. In the prodromal phase, the patient remains withdrawn from the day-to-day surroundings and most of the times maintain a quiet note.
  2. In the active phase, the symptoms of schizophrenia namely hallucination, delusion and other positive symptoms which were discussed above would be manifesting.
  3. This is followed by that of the residual phase in which cognitive symptoms of schizophrenia occurs. 

Diagnosis of Schizophrenia

The diagnosis of schizophrenia according to DSM 5 is based on the occurrence of 2 out of the 5 listed below. It should be noted that among this 5, one among the first 3 three should be present for characterizing a person as schizophrenia.

  1. Hallucination
  2. Disorganised speech
  3. Delusion
  4. Disorganised/ catatonic behavior
  5. Negative symptoms

The minimum duration for which these symptom needs to be present is for about 6 months with at least 1 month of active phase among that period with all the other differential diagnoses excluded.

The neuroimaging of the schizophrenia has shown alteration in the size of the ventricles in the patient along with the change in the brain structures sizes. Although this could not use in the diagnosis of the schizophrenia, the significance of this related to the pathology is evaluated. 


Image: “Image showing brain areas more active in controls than in schizophrenia patients during a working memory task during a fMRI study. Two brain slices are shown.” by Kim J, Matthews NL, Park S. – PLoS One. 2010 Aug 11;5(8):e12068. An event-related FMRI study of phonological verbal working memory in schizophrenia.doi:10.1371/journal.pone.0012068.g002. PMID 20725639. License: CC BY 2.5

Differential Diagnosis of Schizophrenia

The schizophrenia symptoms coexistent along with other psychiatric conditions such as depression, anxiety disorders, and substance abuse. It may also be the case that it could be a case of depression and anxiety disorder alone rather than schizophrenia.

Other differential diagnoses could include bipolar disorder, psychosis which are drug induced, the intoxication of the drug, personality disorders, anxiety disorders and schizotypal personality disorder. The obsessive compulsive disorder also constitutes an important differential diagnosis as this condition occurs with the schizophrenia. Sometimes the cause might be entirely organic rather than that of psychotic, these include systemic infection, limbic encephalitis, multiple sclerosis, hyperthyroidism, frontotemporal dementia, and delirium.

The social complications include isolation in the social meeting, repeated health and medical problems, a victim of bullying in the society and the development of aggressive behavior as a consequence of all this. 

Therapy of Schizophrenia

There needs to be multimodal treatment with a team of specialist while treating schizophrenia. The antipsychotic constitutes the main mode of treatment for this disease.

Pharmacological treatment

The antipsychotic broadly fall into two categories namely the second generation and the first generation antipsychotic.

Second generation antipsychotics

  • It has a low risk of serious side effects, while the first generation antipsychotic drugs cause neurological side effects such as chorea and movement disorders such as tardive dyskinesia.
  • Drugs which fall under second generation antipsychotics include aripiprazole, cariprazine, clozapine, olanzapine, quetiapine, risperidone, brexpiprazole.
  • One of the advantages of second generation antipsychotics is that it offers equal efficacy to that of second generation antipsychotic but being cheaper at the same time.

First generation antipsychotics

  • The first generation antipsychotics include chlorpromazine, fluphenazine, perphenazine, and haloperidol.

Image: “Risperdal (United Kingdom packaging).” by Housed. License: CC BY-SA 3.0

In one of the meta-analyses, published in the British Journal of Psychiatry, among the typical and atypical antipsychotic for the treatment of the schizophrenia, there occurs no difference between the both in terms of the efficacy (the discontinuation rate and the effect on the symptom were taken as outcomes) but when the side effect of the two are compared there occurred a clear demarcation in the incidence of the side effect. The atypical showed more weight gain (2.1 kg more than the typical) and the typical antipsychotic showed more of the extrapyramidal side effect.

The other drugs which are used in the pharmacotherapy include:

  • Antidepressant
  • Anti-anxiety drugs

There are also attempts at identifying the early prodromal stage so that the treatment might be initiated at an early stage with the aim of a better prognosis. With the current technology, the prodromal phase can be identified 30 months before the onset of the main symptoms.

Psychological counseling

Along with the drugs, there also need to be given counseling to the patient. The individual psychological treatment should be given to the patient. Add on to this, training is given to patients so that he might be able to carry out his day-to-day social activities.

The family of the patients is also trained to deal with the various aspects regarding the patient’s attitude. Various rehabilitation programs for giving vocational training aiming self-employment are also carried out as a part of the treatment program.

Another treatment which has shown benefit is the self-instructional training which basically works on the principle that people with schizophrenia perform better after giving instructions for work rather than placing reward system for improving their performance.

Electroconvulsive therapy

It constitutes the last means of therapy to those patients who did not respond to the drug therapy as well as the psychological counseling. In some of the patients, the electroconvulsive therapy had some significant result in overcoming the schizophrenia. 

Complications of Schizophrenia

One of the most dreaded complications of schizophrenia is a risk of suicidal tendency and the suicidal thoughts, which can make a person kill himself (described as a hallucination or delusion telling the person to kill himself). In addition to this, there also occurs progression of the spectrum from positive to the negative symptoms, which also decreases the prognosis of the disease. The concurrent conditions of Obsessive Compulsive Disorder and anxiety disorders and some forms of eating disorders also can occur in more prominence in some of the patients and can be regarded as complications. 

Prevention of Schizophrenia

Although there is no established proven to strategy to prevent the development of schizophrenia, the etiologies which have been described above can be considered while formulating the prevention aspects of the schizophrenia. The avoidance of drug abuse, avoiding the practice of bullying the children, taking care of the child when they have undergone any mental trauma, avoidance of isolations of the child which are generally seen in the affluent society.

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