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Artistic impression of a man experiencing schizophrenia symptomsSchizophrenia is a long-term mental illness, which usually develops during a person's teens or twenties. Different people with schizophrenia can have very different problems. You can have times where the symptoms cause more problems and other times when they're well managed. It can usually be very effectively treated with medications.

Having schizophrenia doesn't mean you have multiple personalities. You have one stable personality, but your thinking may be disordered, or it may be hard for you to tell what is real and what is imaginary.

Many people think people with schizophrenia are dangerous, but that usually isn't true. Most people with schizophrenia pose no more risk than people without schizophrenia.

Causes of schizophrenia

The exact cause of schizophrenia is unknown. Different people may have different causes. This may be why there is a wide variation in symptoms and in the way it develops.

Schizophrenia runs in families. If you have a parent, brother or sister who has schizophrenia, you have a higher chance of developing schizophrenia. But most people who have a family member with schizophrenia will not develop the condition.

Injuries to your brain may be a factor in developing schizophrenia. This could include not getting enough oxygen at birth or your mother having a viral infection during the early months of her pregnancy with you.

Heavy use of cannabis seems to double your risk of developing schizophrenia and stronger forms of cannabis may increase this risk. Cannabis is more likely to trigger schizophrenia if you start using it in your early teens or have smoked it a lot (more than 50 times). Using methamphetamine (P) may also increase your risk.

Childhood stresses and trauma, such as abuse are also linked to an increased chance of developing mental illnesses in adults.

Symptoms of schizophrenia

The symptoms of schizophrenia vary between people, and you may have different symptoms at different times.

The main symptoms are the same as psychosis, plus changes in behaviour and mood or function.

Psychotic symptoms include:

Mood or function symptoms may include one or more of the following:

Many people with schizophrenia have loss of insight. This means you're no longer aware that the experiences and difficulties you have are the result of your illness.

Treating schizophrenia

Ways to treat schizophrenia symptoms include counselling and psychological therapy, social support and medication. Read more on Getting help with psychosis.

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Written by HealthInfo clinical advisers. Last reviewed September 2023.


See also:

Self-care with psychosis

Supporting someone with psychosis

Page reference: 243419

Review key: HIPSY-124133