What Causes Psychosis?

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Psychosis is characterized by losing connection with reality. It is not a mental health condition but is instead a symptom of many different mental disorders.

It causes people to experience hallucinations, delusions, and incoherent behaviors. When a person is experiencing psychosis, their distorted perceptions and thoughts interfere with their ability to determine what is real and what is not real.

The exact causes of psychosis are not entirely clear, but factors such as genetics, environment, illness, and mental disorders can all play a potential role. This article explores some of the common causes that are associated with psychosis. 

Common Causes

Some of the most common causes associated with psychosis include:

  • Schizophrenia and other mental disorders
  • Physical illness
  • Substance use
  • Trauma

While some causes of psychosis are related to factors that cannot be changed such as genetics, there are sometimes steps people can take to minimize their risk of experiencing psychosis. For example, avoiding substance use and getting treatment for mental health conditions can minimize the risk of having a psychotic episode.

Genetic Causes of Psychosis

Some evidence suggests that genes can increase your risk of developing psychosis. If someone in your family has had a psychotic episode, you may have a slightly higher risk of experiencing one too. 

The genetic causes are believed to be highly complex, but a number of different genes have been implicated in raising a person’s risk of developing psychosis.

It is important to note that while psychosis appears to have a genetic component, having a family member with a psychotic condition does not necessarily mean you will also develop the condition.

Mental Health Conditions

Psychosis is a symptom of a number of different mental health conditions. Some conditions that can cause episodes of psychosis include:

Bipolar Disorder

Bipolar disorder is a condition characterized by recurrent episodes of extremely high moods (mania) and extremely low moods (depression). Psychosis can occur when a person has this condition, but they tend to be more common during a manic episode.

While the experience varies from one person to the next, psychotic symptoms that often occur in bipolar disorder include:

  • Disorganized thinking: People may have incoherent, confusing thoughts that make it difficult for them to function and interact normally.
  • Grandiosity: Those with the condition can experience an inflated sense of self characterized by feelings of grandeur and the belief that the person is uniquely special or that they have special powers.
  • Hallucinations: Individuals may see or hear things that are not really there.

Brief Psychotic Disorder

This involves a short-term occurrence of psychotic behavior. It often occurs as a result of a stressful event. A brief psychotic episode can last from one day to up to a month. 

Major Depressive Disorder With Psychotic Features

Sometimes referred to as psychotic depression, symptoms of psychosis may also sometimes occur in this type of major depressive disorder.  People with this condition have symptoms of depression such as sadness, irritability, and loss of interest. However, they also experience delusions, hallucinations, or both.

Statistics suggest that around four people out of every 1,000 will experience an episode of depression with psychotic features. The risk appears to increase with age and is more common in people age 60 and older.


Psychosis is a hallmark symptom of schizophrenia, a serious mental health condition that causes disordered thoughts and behaviors. People who have this condition can experience positive symptoms (which means that they cause changes in behavior and thought) as well as negative symptoms (which are marked by people withdrawing from the world). 

In order to be diagnosed with schizophrenia, a person must experience at least one psychotic episode. These episodes are marked by delusions, hallucinations, and disorganized speech as well as disorganized behavior and negative symptoms such as a lack of emotional expression.

Postpartum Psychosis

At its most severe, postpartum depression may lead to symptoms of psychosis, which is serious and requires hospitalization. Postpartum psychosis most commonly occurs within two weeks of giving birth. Research suggests that having bipolar disorder or schizoaffective disorder increases the risk of developing postpartum psychosis.

Schizoaffective Disorder

Schizoaffective disorder is a condition marked by symptoms of both psychosis and mood disruptions. Similar to schizophrenia, this condition causes people to experience problems in how they perceive reality. Along with hallucinations and delusions, they also experience problems with emotions, thinking, and social interactions.


A number of mental health conditions can cause psychosis. This includes psychotic conditions such as schizophrenia, schizoaffective disorder, and brief psychotic disorder. Other disorders such as bipolar disorder and major depressive disorder with psychotic features can also cause psychosis.

Substance Use

Psychosis can also be caused by the use of recreational substances. In some instances, prescription medications can also trigger a psychotic episode, particularly if they are misused or a person overdoses. 

When a person experiences psychosis as a result of taking a substance, it is known as substance/medication-induced psychotic disorder.

Substances that might cause psychosis include:

People with a history of substance abuse are at an increased risk of developing psychosis. This may be due to the effects that drugs and alcohol have on the brain, or it may be that people with underlying mental health conditions are more likely to self-medicate with substances.


Traumatic life events, such as abuse or violence, can also increase the risk for psychosis. Being exposed to the trauma of war or enduring the death of a loved one, for example, has been known to play a role in the emergence of psychosis. Some symptoms of psychosis, particularly hallucinations, can occur when a person has post-traumatic stress disorder (PTSD) following a traumatic experience.

However, evidence also suggests that the association between trauma and psychosis is complex. Psychosis may occur as a part of PTSD as a result of having experienced a traumatic experience, but experiencing psychotic symptoms can also lead to trauma.

Estimates suggest that 30% of people with a psychotic disorder are diagnosed with PTSD. For comparison, around 7.8% of the general population is diagnosed with PTSD.

Medical Conditions and Injury

Damage to the brain from illness or injury can also cause psychosis. A number of different medical conditions can also cause episodes of psychosis.

Some of these conditions include:

Psychosis can occur following a traumatic brain injury. Being deficient in folate and vitamin D has been linked to the onset of schizophrenia and the worsening of psychotic symptoms.

A Word From Verywell

While the causes of psychosis are not completely understood, it is clear that there are many different factors that can play a role. If you or someone you know is experiencing symptoms of psychosis, it is important to seek professional help right away. There are effective treatments available that can help people recover. Consult your healthcare provider to learn more about your options and to determine why you are experiencing this symptom.

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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Kendra Cherry, MSEd
Kendra Cherry, MS, is a psychosocial rehabilitation specialist, psychology educator, and author of the "Everything Psychology Book."