for better mental health

Psychosis

Explains what psychosis is, including possible causes and how you can access treatment and support. Includes tips for helping yourself, and guidance for friends and family.

What causes psychosis?

The cause of psychosis can be different for everyone, and research into it is happening all the time. Psychosis could be triggered by a number of things, such as:

  • Physical illness or injury. You may see or hear things if you have a high fever, head injury, or lead or mercury poisoning. If you have Alzheimer's disease or Parkinson's disease you may also experience hallucinations or delusions.
  • Abuse or trauma. If you have experienced abuse or a traumatic event, you are more likely to experience psychosis.
  • Recreational drugs. Researchers still aren't sure whether using recreational drugs directly causes psychosis but you may be more likely to hear or see things as a result of taking certain recreational drugs, like cannabis and LSD. If you have already experienced psychosis, using recreational drugs can make the symptoms worse, in particular if you take high-potency cannabis ('skunk').
  • Alcohol and smoking. Drinking alcohol and smoking may also stop medication from effectively treating your symptoms, making relapse more likely.
  • Prescribed medication. You might also experience psychosis as a side effect of some prescribed drugs or while you are coming off psychiatric drugs.

"It's an illness that can be treated just like any other. I don't choose or want to be psychotic any more than people choose or want any other types of ill health."

  • Hunger. You may experience hallucinations if you are very hungry, have low blood sugar or if you are not getting enough food.
  • Lack of sleep. You may experience hallucinations if you have a severe lack of sleep.
  • Bereavement. If you have recently been bereaved, you may hear them talking to you. You may also feel that they are with you even though you can't see them.
  • Spiritual experiences. Some people experience voices or visions as part of a spiritual experience. This may be a positive experience for you. It may make you feel special or important and help you make sense of your life. It could however also be a negative experience – for example, you may feel that you're possessed by an evil spirit.
  • Genetic inheritance. You are more likely to develop psychosis if you have a parent or sibling who has experienced psychosis, but researchers aren't sure why this happens.

This information was published in January 2020. We will revise it in 2023.

References are available on request. If you would like to reproduce any of this information, see our page on permissions and licensing.

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