Undergoing a psychotic episode is one of the most distressing things an individual can go through. It can leave them scared, anxious and confused.

A lot of the time an individual will come to expect a psychotic episode as part of a diagnosed condition. But sometimes someone will experience psychosis without having a known condition.

It is understandable in both respects to want to know the causes of psychosis. This article explores the causes behind psychosis.

Psychosis often involves altered chemicals in the brain

What is Psychosis?

Psychosis: Psychosis is a very serious mental health problem that causes an individual to see, perceive or interpret things in very different ways to others. The most well-known signs of psychosis are hallucinations and delusions. Those who suffer from psychosis are said to “lose touch” with reality. Psychosis is a very serious problem that can have severe repercussions on both the individual suffering, and those around them. In rare cases, psychosis can be a positive thing – with some suggesting they can hear the voices of dead loved ones. Unfortunately, the majority of people have serious ill health when suffering from symptoms of psychosis. Psychosis itself isn’t a mental health condition, though is a key part of mental health, and plays a role in several conditions where psychotic episodes are common.

What are some potential causes of Psychosis?

Unfortunately, it isn’t always clear what causes psychosis – it is a complex state of affairs. It appears that certain risk factors and triggers may exist. These include, but aren’t limited to:

  • Brain Differences: The neurotransmitter Dopamine appears to be key in psychosis. Dopamine is just one of the many chemicals in the brain that helps transfer information to other cells. It is believed those who suffer psychotic episodes have an abnormally high level of dopamine. Scans on the brains of individuals with psychosis appear to back this belief up [1].
  • Medical Condition: A host of medical conditions have been known to trigger psychotic episodes in a small number of people. Just some of these conditions include HIV and AIDS, Malaria, Parkinson’s disease and a brain tumour [2].
  • Traumatic Experience: A traumatic experience can have a profound effect on an individual. This includes any trauma in childhood, such as abuse. As a result, a plethora of mental health conditions can develop. Sometimes a psychotic episode can ensue.
  • Substance Abuse: Substance abuse has long been linked to psychotic episodes. A psychotic episode is a common symptom of withdrawal from either drugs or alcohol – especially if they have been taken on a long-term period. Those who are ‘high’ on drugs or have consumed an excessive amount of alcohol can sometimes encounter a psychotic episode. However, this should stop once drug detoxification is complete.
  • Genetics: As with all other mental health conditions, psychosis appears to run in families. Statistics suggest an individual is fifteen times more likely to experience psychosis if their parent experienced psychosis, when compared to those without [3].
  • Stress: If an individual is acutely stressed, sometimes a psychotic episode can follow. This appears to be linked to the chemical cortisol. Naturally, when someone is stressed, the brain releases cortisol, which appears to be linked to psychosis developing.
  • Birth Complications: People who had a complicated birth appear to have an increased risk of developing psychosis [4]. Complications include premature birth or a lack of oxygen.
  • Side Effect of Medication: In rare cases, an unwanted side effect of a medication could be a psychotic episode. While rare, it is impossible to determine how a body will react to the introduction of any medication. So on rare occasions, psychosis is possible.
  • Serious Injury: A head injury, or any condition that affects the brain can induce the symptoms of psychosis. Injuries near the brain run the risk of causing chronic psychosis problems.


As seen in this article, there is no shortage of possible causes of psychosis. Any individual can develop psychosis, regardless of whether or not factors like genetics make it more likely or not.

Anyone can feasibly develop psychotic symptoms. If the symptoms do appear, seeking treatment is crucial.

See Also

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[1] Tost, H., Alam, H., & Meyer-Lindenberg, A. (2010). Dopamine and Psychosis: Theory, Pathomechanisms and Intermediate Phenotypes. Neuroscience & Biobehavioral Reviews. 34 (5): p689-700. DOI: https://doi.org/10.1016/j.neubiorev.2009.06.005.

[2] Singer, E. J., & Thames, A. D. (2016). Neurobehavioral Manifestations of HIV/AIDS: Diagnosis and Treatment. Neurologic Clinics. 34 (1): p33-53. DOI: https://doi.org/10.1016%2Fj.ncl.2015.08.003.

[3] O’Donovan, M. C., Craddock, N. J. & Owen, M. J. (2009). Genetics of psychosis; insights from views across the genome. Human Genetics. 126 (1), p3-12. DOI: https://doi.org/10.1007/s00439-009-0703-0.

[4] Dalman, C., Allebeck, P., Cullberg, J., Grunewald, C., & Koster, M. (1999). Obstetric Complications and the Risk of Schizophrenia. Archives of General Psychiatry. 56 (3): p234-240. DOI: https://doi.org/10.1001/archpsyc.56.3.234.