Psychosis is a mental health problem that causes people to perceive or interpret things differently from those around them. This might involve hallucinations or delusions.

The two main symptoms of psychosis are:

  • hallucinations   where a person hears, sees and, in some cases, feels, smells or tastes things that aren't there; a common hallucination is hearing voices
  • delusions where a person believes things that, when examined rationally, are obviously untrue for example, thinking your next door neighbour is planning to kill you

The combination of hallucinations and delusional thinking can often severely disrupt perception, thinking, emotion and behaviour.

Experiencing the symptoms of psychosis is often referred to as having a psychotic episode.

What causes psychosis?

Psychosis isn't a condition in itself it's triggered by other conditions.

It's sometimes possible to identify the cause of psychosis as a specific mental health condition, such as:

  • schizophrenia  a condition that causes a range of psychological symptoms, including hallucinations and delusions
  • bipolar disorder  a mental health condition that affects mood; a person with bipolar disorder can have episodes of depression (lows) and mania (highs)
  • severe depression some people with depression also have symptoms of psychosis when they're very depressed

Psychosis can also be triggered by traumatic experiences, stress or physical conditions, such as Parkinson's disease, a brain tumour, or as a result of drug misuse or alcohol misuse.

How often a psychotic episode occurs and how long it lasts can depend on the underlying cause.

For example, schizophrenia can be long-term, but most people can make a good recovery, and about a quarter only have a single psychotic episode. Episodes related to bipolar disorder usually resolve, but may reoccur.

Read more about the causes of psychosis.

Diagnosing psychosis

You should see your GP immediately if you're experiencing psychotic episodes. It's important that psychosis is treated as soon as possible, because early treatment usually has better long-term outcomes.

Your GP will look at your symptoms and rule out short-term causes, such as drug misuse. They may ask you some questions to help determine what's causing your psychosis. For example, they may ask you:

  • whether you're taking any medication
  • whether you've been taking illegal substances
  • how your mood has been for example, whether you've been depressed
  • how you've been functioning day-to-day for example, whether you're still working
  • whether you have a family history of mental health conditions such as schizophrenia
  • about your hallucinations such as whether you've heard voices
  • about your delusions such as whether you feel people are controlling you
  • whether you have any other symptoms

Your GP should refer you to a mental health specialist for further assessment and treatment.

Read more about diagnosing psychosis.

Treating psychosis

Treatment for psychosis involves using a combination of:

  • antipsychotic medication which can help relieve the symptoms of psychosis
  • psychological therapies the one-to-one talking therapy cognitive behavioural therapy (CBT) has proved successful in helping people with schizophrenia and, in appropriate cases, family therapy has been shown to reduce the need for hospital treatment in people with psychosis
  • social support support with social needs, such as education, employment or accommodation

Most people with psychosis who get better with medication need to continue taking it for at least a year. Some people need to take medication long term to prevent symptoms reoccurring.

If a person's psychotic episodes are severe, they may need to be admitted to a psychiatric hospital.

Read more about the treatment of psychosis.

Getting help for others

People with psychosis often have a lack of insight. They're unaware that they're thinking and acting strangely.

Due to their lack of insight, it's often down to the friends, relatives or carers of a person affected by psychosis to seek help for them.

If you're concerned about someone you know and think they may have psychosis, you could contact their social worker or community mental health nurse if they've previously been diagnosed with a mental health condition.

If you think the person’s symptoms are placing them at possible risk of harm you can:

  • take them to the nearest accident and emergency (A&E) department, if they agree
  • call their GP or NHS 24 on 111 
  • call 999 and ask for an ambulance

Read more about how to get help for others.


People with a history of psychosis are much more likely to have drug and/or alcohol misuse problems.

This may be because such substances can provide short-term symptom relief, although they usually make symptoms worse in the long term.

People with psychosis also have a higher than average risk of suicide. It's estimated that 1 in 5 people with psychosis will attempt to commit suicide at some point in their life, and 1 in 25 people with psychosis will kill themselves.

Side effects can also occur if taking antipsychotics on a long-term basis. Weight gain is a common side effect. In rare cases, a person with psychosis may also develop type 2 diabetes.

Read more about the complications of psychosis.

Last updated: 20 November 2015

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