Schizophrenia Causes

(Also Known As: Paranoid Schizophrenia Causes, Schizophrenic Causes, Delusional Causes, Psychosis Causes)

(Reviewed by: Paul Peterson, Licensed Therapist)

What Causes Schizophrenia?

The causes of schizophrenia are considered to be a combination of genetic and environmental factors. No single cause of schizophrenia has been identified at this time, and modern tools of biochemical research are being exhausted in order to search for the genetic and brain development causative factors that may lead to this disorder. Some of the possible causes of schizophrenia may be due to the interplay of the following factors:


  • Genetic Inheritance

It has been a common knowledge that schizophrenia always run in the family. The risk is higher in those who have known family members and close relatives with schizophrenia. Children with schizophrenic parents have a 10% chance of developing the condition.

Multiple genes are believed to be involved as a predisposing factor to develop schizophrenia.

Prenatal difficulties such as intrauterine starvation, viral infection, perinatal complications may also influence the onset of the disorder. Chromosomes 13 and 6 are highly suspected with the transmission of schizophrenia, however this assumption remains to be unconfirmed.

  • Chemical defects in the Brain

Abnormal and imbalanced functions of the brain’s neurotransmitters are believed to be involved in the development of schizophrenia. The association of the imbalanced complex and interrelated systems of the brain that involve dopamine and glutamate actions can also affect the development of schizophrenia.

  • Physical Abnormality of the Brain

Through the aid of neuroimaging technology, scientists were able to study the structures of the brain and its function and they have associated schizophrenia to occur due to some brain structural and functional abnormalities. Abnormal brain structures include the presence of an enlarged ventricle or a decrease in size of a brain region, with functional abnormalities such as decreased metabolic activity in the brain region that can possibly contribute to schizophrenia.

The structural abnormalities in the brain however are often subtle and are not a significant characteristic of individuals with schizophrenia.

Abnormal fetal development of the brain can also be attributed as a possible cause for the development of schizophrenia.

  • Environmental Causes

Environmental factors play a significant role in triggering individuals who are at high risk of developing schizophrenia, such as those that are genetically at risk. Environmental stress can also be the culprit of abnormal development during pregnancy. A high level of stress is believed to cause hormonal changes, which increases the body’s cortisol level.

Stress inducing factors that can contribute to the development of schizophrenia include:

  1. low oxygen level during birth
  2. prenatal exposure to viral infection
  3. early parental loss or separation
  4. physical or sexual abuse during childhood
  5. exposure to virus during pregnancy
  • Birth Complications

Pre-eclampsia pregnancy complication

Abnormal fetal growth such as low birth weight and reduced head circumference


Emergency caesarian section

  • Infections

Polio varius

Flu virus

Encephalitis lethargica

  • Head Injury

Traumatic brain injury


Traumatic accidents


  • The major psychological trigger for schizophrenia to occur is life’s stressful events. These events may range from a death of a loved one, unemployment, birth loss, and many others.
  • Social factors also play a role in the development of schizophrenia. Individuals with no genetic predisposition to the condition can be triggered to have the conditions due to institutional and individual racism, poor housing, social isolation, low employment level, and lack of cultural identity. 4

Could You Have Schizophrenia?

Schizophrenia Topics

Related Conditions

Bipolar Disorder – Psychosis, Hallucinations, Delusions, Suicide, Hypomania, Hypermania
Borderline Personality Disorder – Mood Variations/Changes, Unstable Interpersonal Relationships, Dissociation
Schizotypal Personality Disorder – Social Isolation, Odd Behavior, Unconventional Beliefs, Paranoia, Social Anxiety