The symptoms of schizophrenia usually appear in late adolescence or early adulthood. Schizophrenia can affect a person’s speech, thinking, emotions as well as social interactions and other everyday activities.

Schizophrenia is a fairly uncommon condition, affecting around 0.25–0.64% of people in the United States. It can have a profound impact on a person’s life, as well as the lives of those around them.

Schizophrenia is a lifelong condition, but treatment can help manage the symptoms.

This article will look at the causes and symptoms of schizophrenia and some of the treatment options available.

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The symptoms of schizophrenia usually emerge when a person is in their late teens or early 30s. They tend to develop earlier in males than in females.

Sometimes, a person will start to show unusual behaviors from childhood, but these only become significant as they get older. In others, the symptoms may appear suddenly.

Learn more about the average age of onset for schizophrenia here.

The classifications and types of schizophrenia have changed over the years. Previously, health professionals may have classified schizophrenia as one of the following five types:

However, doctors no longer classify types of schizophrenia. The Diagnostic and Statistical Manual of Mental Disorders (DSM5) is the manual mental health professionals use to diagnose mental health conditions. The current version, DSM-V, no longer uses these categories. This is because health experts noted that the previous types had many overlapping features and symptoms.

Click here to learn more about the different types of schizophrenia.

Schizophrenia affects people in different ways, but there are some common symptoms. These include:

  • confused speech that is intact but hard for others to interpret and 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

The sections below will discuss some of the main symptoms of schizophrenia in more detail.


A person experiencing delusions has a fixed belief about something regardless of the evidence.

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.


Some people experience hallucinations. The most common type is hearing voices, but hallucinations can affect all the senses. For example, a person may also see, feel, taste, or smell things that are not really there.

Confused thinking and speech

A person’s thinking, and speech, may jump from one subject to another for no logical reason. It may therefore be hard to follow what the person is trying to say.

There may also be memory problems and difficulty understanding and using information.

Other symptoms

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

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

Many people with schizophrenia do not realize that they are unwell. Hallucinations and delusions can seem very real to a person who is experiencing them. This can make it hard to convince the individual to seek treatment or take medication. They may fear the side effects or believe that medication will harm them.

Schizophrenia usually appears in a person’s late teens or older, but it can also affect children.

Learn more about the symptoms of schizophrenia here.

Schizophrenia likely develops when specific genetic and environmental factors combine.

For example, the following factors might all contribute to the development of schizophrenia:

Genetic inheritance

If there is no history of schizophrenia in a family, the chances of developing it are low. However, a person’s risk rises if one of their parents has a diagnosis of schizophrenia.

A chemical imbalance in the brain

Schizophrenia appears to develop when there is an imbalance of the neurotransmitter dopamine and possibly 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

In 2017, scientists found evidence to suggest that some substances in cannabis can trigger schizophrenia in those susceptible to it.

Others, however, have suggested that having schizophrenia may make a person more likely to use cannabis in the first place.

Learn about cannabis and schizophrenia here.

People with untreated schizophrenia are more likely to self-harm and be violent toward others than those who have received treatment.

A 2015 study in China compared outcomes for 123,572 people with treated and untreated schizophrenia 14 years after they received a diagnosis.

After 14 years, people who did not receive treatment were more likely to:

  • be older
  • have fewer family members
  • be homeless
  • have died from other causes
  • be unmarried
  • live alone
  • be without a caregiver
  • have poorer family attitudes

The researchers also found that 57.3% of treated people experienced partial or complete remission, compared to 29.8% in the never-treated group.

If someone is showing symptoms of schizophrenia, it is important to get prompt treatment.

Learn about treatment-resistant schizophrenia here.

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

Each person’s experience will differ, and a doctor will tailor the treatment to suit the individual.

Some potential treatment options include:

  • Antipsychotic drugs. People can take these daily or less frequently if they opt for injectable medications, which can last up to 3 months, depending on the medication.
  • Counseling. Mental health counseling can help people 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 older drugs may have adverse effects, including neurological symptoms. Newer medications typically have different side effects, such as weight gain.

It is essential for a person to continue with their treatment plan, even if the symptoms improve. If a person stops taking medication, the symptoms may return.

Learn about antipsychotic drugs for schizophrenia here.

There is no diagnostic test to assess schizophrenia. A doctor will diagnose it by observing how the person behaves. They will also ask about their history of physical and mental health.

That said, they may recommend some tests to rule out other possible causes of the symptoms, such as a tumor, brain injury, or another mental health condition, such as bipolar disorder.

Diagnostic criteria

To diagnose schizophrenia, a doctor will use the criteria from the DSM-5. This manual provides criteria for diagnosing a wide range of mental health conditions.

According to the criteria, a person must have at least two of the following symptoms for a month:

  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 must also experience considerable impairment in their ability to function in school or at work, interact with others, or carry out self-care tasks.

They must also have symptoms that persist for 6 months or more. The symptoms must also not be due to another health condition, a prescribed medication, or the use of other substances.

The symptoms must also not be due to another health condition, a prescribed medication, or the use of other substances.

Learn about the stages of schizophrenia here.

Schizophrenia is a long-term condition that can profoundly affect a person’s ability to function. These effects can also affect the people around them.

Treatment is available that can help a person manage their symptoms. People with schizophrenia will also benefit from the support of their family, friends, and community services.

Anyone caring for someone with schizophrenia can help by learning how to spot the onset of an episode, encouraging the person to adhere to their treatment plan, and supporting them through their experience.

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