Understanding the causes of schizophrenia

Understanding the causes of schizophrenia

Schizophrenia is a condition of mental health that typically shows up in late adolescence or early adulthood. Its impact on speech, thinking, emotions, and other areas of life can affect a person’s social interactions and everyday activities.

According to the National Institute of Mental Health (NIMH), schizophrenia is a relatively rare disease affecting about 0.25 percent to 0.64 percent of people in the United States. It can have a profound effect on the life of a person, and on the lives of those around them.

The symptoms typically occur when a person is between early teens and early 30s. In males they tend to develop earlier than in females.

In certain cases , a person may start exhibiting unusual childhood behaviors, but these only become important as they get older. The symptoms may all of a sudden appear in others.

Schizophrenia is a lifelong disorder but therapy may assist with symptoms control.

This article looks at the causes and symptoms of schizophrenia, as well as some of the current treatment options.


Schizophrenia typically appears in late adolescence or early adulthood.
Schizophrenia typically appears in late adolescence or early adulthood.

In different ways, schizophrenia affects various individuals but there are some general symptoms. Including:

  • confused speech that is hard for others to understand
  • lack of facial expression
  • lack of emotional expression
  • lack of motivation
  • difficulty concentrating
  • psychosis, such as delusions and hallucinations

Before experiencing these symptoms, a person may appear:

  • out of sorts
  • anxious
  • to lack focus

Some of the principal symptoms of schizophrenia are discussed in more detail in the sections below.


A person who has delusions can believe something is true when there is no clear evidence for it.

For example, they may believe that:

  • they are very important
  • someone is pursuing them
  • others are attempting to control them remotely
  • they have extraordinary powers or abilities


Several people suffer hallucinations. Hearing voices are the most common type but hallucinations may affect all the senses. A person can also see, feel, taste , or smell things that aren’t actually there, for example.

Confused thinking and speech

A person’s thought, and voice, can for no logical reason jump from one topic to another. Thus, it can be difficult to understand what the person is trying to say.

Memory issues can also occur, and knowledge can be difficult to understand and use.

Other symptoms

The symptoms listed above can also affect a person’s:

  • Motivation: The person may neglect everyday activities, including self-care. They may experience also catatonia, during which they are barely able to talk or move.
  • Emotional expression: The person may respond inappropriately or not at all to sad or happy occasions.
  • Social life: The person may withdraw socially, possibly through fear that somebody is going to harm them.
  • Communication: The person’s unusual thought and speech patterns can make it difficult for them to communicate with others

Many people who suffer from schizophrenia do not realize they are unwell. To a person who experiences them, hallucinations and delusions can seem very plausible. That can make it difficult to convince the individual to take medication. They may be fearful of the side effects, or think they would be affected by the drug.

Schizophrenia typically occurs when a person is younger or older but it can also affect children.


According to the NIMH, schizophrenia typically occurs when specific genetic and environmental factors overlap.

The following causes, for example, may all lead to the development of schizophrenia:

Genetic inheritance

If there is no history of schizophrenia in a family, the chances of developing it are less than 1 percent. person’s risk rises, however, increases if one of their parents has a diagnosis of it.

A chemical imbalance in the brain

Schizophrenia appears to develop when there is an imbalance of a neurotransmitter called dopamine, and possibly also serotonin, in the brain.

Environmental factors

Environmental factors that may increase the risk of schizophrenia include:

  • trauma during birth
  • malnutrition before birth
  • viral infections
  • psychosocial factors, such as trauma

Certain drugs and medications

Scientists found evidence in 2017 to suggest that certain substances in cannabis can trigger schizophrenia in those susceptible to it.

However, others have indicated that having schizophrenia can initially make a person more likely to use cannabis.


Schizophrenia is a lifelong condition, but effective treatment can help an individual manage the symptoms, prevent relapses and prevent hospitalization.

The experience of each person will be different, and a doctor will tailor the treatment according to the individual’s needs.

Some potential treatment options include:

  • Antipsychotic drugs. These can be for daily use or for less frequent use if the person opts for injectable medications, which can last up to 3 months between injections (depending on the medication).
  • Counseling. This can help a person develop coping skills and pursue their life goals.
  • Coordinated special care. This integrates medication, family involvement, and education services in a holistic approach.

Some common medications for schizophrenia include:

  • risperidone (Risperdal)
  • olanzapine (Zyprexa)
  • quetiapine (Seroquel)
  • ziprasidone (Geodon)
  • clozapine (Clozaril)
  • haloperidol (Haldol)

That said, many of these drugs have adverse effects, including neurological symptoms and weight gain. Newer medications may have less severe side effects, however.

The continuation of a person’s care plan is important, even if the symptoms improve. If a person ceases medication, the symptoms may return.


Health practitioners have in the past pointed to various subtypes of schizophrenia, such as paranoid schizophrenia and schizoaffective disorder. There are no longer such classifications in use.


No diagnostic test is required to determine schizophrenia. A doctor will diagnose it by looking at how the person is acting. They’ll also ask about their physical and mental health backgrounds.

That being said, some tests may be recommended to rule out other possible symptom causes, such as a tumor, brain injury, or other mental health condition, such as bipolar disorder.

Diagnostic criteria

A psychiatrist may use the guidelines from the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders to diagnose schizophrenia. This manual includes medical guidelines for a wide variety of mental health disorders.

A person must have at least two of the following symptoms for a month, in accordance with the criteria:

  1. delusions
  2. hallucinations
  3. disorganized speech
  4. grossly disorganized or catatonic behavior
  5. negative symptoms, such as lack of speech, emotional flatness, or lack of motivation

At least one of these must be 1, 2, or 3.

They may have to suffer severe impairment in their ability to function at school or at work, communicate with others, or perform self-care tasks, and have symptoms that last for 6 months or longer.

Similarly, the symptoms must not be due to another health condition, prescribed medication, or other substance use.


Schizophrenia is a long-term disorder which can have a profound effect on the ability of a individual to function in life. Those effects will affect the people around them as well.

There’s treatment that can help a person manage their symptoms. Schizophrenic people may also benefit from support from their families , friends and community services.

Anyone who cares about someone with schizophrenia can benefit by learning how to spot the onset of an episode, encouraging the individual to pursue their treatment plan and helping them through their experience.