Possible Psychosis Causes: Where Do Hallucinations And Delusions Come From?

Psychosis can be among the most debilitating types of mental illness. Psychosis may take many different forms, but they all tend to involve difficulties with accurately perceiving and understanding what’s real. Those learning about psychosis symptoms like delusions and hallucinations often wonder if they might be at risk, and how they would know if they were. What can cause psychosis, and how can the condition be prevented?

Like many complex forms of psychological dysfunction, psychosis typically has multiple overlapping causes. Severe emotional stress, such as trauma, can play a role, but so can physiological factors, like infections or psychoactive substances. Scientists have also found many genetic variations that appear to impact a person’s vulnerability to psychosis. Reducing the risk of a psychotic episode may involve minimizing exposure to a wide variety of potential risk factors. Working with a therapist to address any mental health challenges can be helpful.

Support your mental health with therapy

Talk to a licensed therapist online

What is psychosis and what are the psychotic symptoms?

While many people use words like “psychotic” to mean any kind of irrational thinking or mental health condition, the term has a precise meaning in the field of psychology. As defined by the American Psychological Association (APA), psychosis refers to any mental state or condition “involving significant problems with reality testing.” In other words, psychosis usually affects a person’s ability to understand what is and is not real.

Psychotic symptoms

Psychotic symptoms can include the following:

• Hallucinations: Sensory perceptions that don’t come from any external source, such as images or sounds of something that isn’t real (Example: Hearing a disembodied voice commenting on your thoughts)
• Delusions: Fixed but false beliefs that a person holds without evidence, or even when presented with evidence against them (Example: Being convinced that the trees in your neighborhood are surveillance devices installed by extraterrestrials)
• Disorganized thought, speech, and/or behavior: Thinking or acting in a way that’s not directed logically or oriented toward rational goals (Example: Jumping rapidly between topics based on loose mental association rather than being able to hold a coherent conversation)
• Negative symptoms: Displaying reductions in mental functions like emotions, purposeful behavior, and verbal fluency (Example: Lacking enjoyment in formerly pleasant activities and having little interest in doing anything)

Experiencing some of these symptoms in a mild or transitory fashion doesn’t necessarily indicate psychosis. For example, some people experience auditory hallucinations, such as hearing nonexistent voices, while remaining mentally healthy, though research suggests they could be at higher risk for psychosis than the general population. 

Psychotic episodes and psychotic disorder

Certain types of mental illness are classified by the current edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as psychotic disorders, including the following:

• Schizophrenia
• Schizophreniform disorder
• Schizoaffective disorder
• Brief psychotic disorder
• Delusional disorder
• Psychotic disorder due to a medical condition
• Psychotic disorder due to substance use or medication

Understanding psychosis in bipolar disorder and other psychiatric illnesses

Other kinds of psychiatric illness may involve psychosis symptoms as a secondary feature, occurring only occasionally or in the context of other symptoms. For example, a person with bipolar disorder might have grandiose delusions (believing themselves to be someone extremely important, such as a divine being or the secret ruler of the world) during a manic period.

The symptoms of psychosis often fluctuate in severity over time. Individuals with psychotic disorders often go through “psychotic episodes” marked by frequent and vivid hallucinations, strongly held delusions, and highly disorganized behavior. After these episodes abate, they may recognize their previous behavior and thinking as disordered.

Risk of relapse after psychosis

A person who experiences a short-term psychotic episode may or may not relapse in the future. Some individuals may have only a single episode of psychosis during their lifespan and never meet the diagnostic criteria for a psychotic disorder. However, any occurrence of psychosis is usually considered a significant risk factor for further episodes.

Possible psychosis disorder causes and risk factors

The precise causes of psychosis aren’t always clear, simple, or straightforward. According to the National Institute of Mental Health (NIMH), this type of psychological illness appears to emerge from a complicated interaction between many genetic, developmental, emotional, and environmental factors. 

Genetic causes of psychosis

Certain genetic variations may confer an increased susceptibility to psychotic disorders. For instance, schizophrenia is typically considered a highly heritable disorder. Some estimates indicate that genetic differences may explain more than 85% of the variance in schizophrenia prevalence.

Unlike some mental disorders, such as Huntington’s disease, this risk can’t be narrowed down to one or two specific genes. Variations in more than 200 different locations within the human genome are thought to modify schizophrenia risk. 

Researchers do not yet know what role all these genes play in developing psychosis. Some appear to be involved in neurological development, suggesting that differences in brain structure could leave some individuals more vulnerable to psychotic symptoms. Others affect immune responses within the nervous system, potentially making physical or mental stress more likely to damage the brain.

Developmental causes of psychosis

Some research suggests that events like these may modify the way genes are expressed in the developing fetus, potentially activating certain genetic risk factors for psychosis.

Possible psychosis causes and their connection to mood disorders like bipolar disorder

There’s also evidence that serious mental strain can contribute to the emergence of psychosis. People experiencing severe depression, anxiety, mania, or other kinds of emotional disruption may undergo psychotic episodes, and intense stress may trigger psychotic disorders in high-risk individuals. Psychotic features are sometimes observed in mood disorders, such as bipolar disorder or major depressive disorder. 

The link between stress and psychosis may be partly explained by hyperactivity in the hypothalamic-pituitary-adrenal (HPA) axis, a network of nerves and glands that can modify multiple bodily systems in response to stress. This excessive activity may cause the overexpression of psychosis risk genes or create harmful levels of inflammation that can damage important brain regions.

Stressful events early in life may be particularly significant for the later development of psychosis. Undergoing trauma in childhood is considered a well-known risk factor for schizophrenia and related disorders. Other environmental factors in childhood, such as involuntary migration or growing up in a chaotic and unsafe neighborhood, can also play a role. 

Experiences of this kind may interfere with an individual’s development of emotional regulation skills, cause them to psychologically dissociate, or have negative impacts on brain development, all of which could contribute to psychosis risk.

Pharmacological causes of psychosis

Certain psychoactive chemicals can induce symptoms like delusions and hallucinations. Although relatively rare, some people experience psychosis as a side effect of prescription medications, such as those listed below:

• Anti-seizure drugs like levetiracetam
• Corticosteroids like prednisone
• Antiretroviral drugs like efavirenz
• Anti-malaria medications such as chloroquine

Always consult your doctor before you start, stop, or change the way you take any kind of medication, and be sure to inform them if you experience any side effects.

The use of some recreational substances may also precipitate psychosis, especially when taken in excess over long periods. Substances commonly associated with this effect include the following:

• Cocaine
• Methamphetamine
• Cannabis (especially high-THC varieties)
• Synthetic cannabinoids
• Psychedelics like LSD or mescaline
• Ketamine
• PCP

Substance and alcohol withdrawal syndromes can also involve psychotic symptoms.

Substance use may interact with other risk factors for psychosis. People with a high genetic risk for schizophrenia, for example, may trigger the onset of the disorder by using substances.

Illnesses as causes of psychosis

Some individuals develop psychosis because of other medical conditions. This may be due to direct pathological effects on the brain or as a result of the physiological and psychological stress caused by illness. A high fever during an illness can also cause a temporary state of psychosis. 

Neurodegenerative disorders, such as Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis, are often associated with psychosis as well. Other illnesses that can have this effect include those listed below:

• HIV or AIDS
• Lupus
• Diabetes and hypoglycemia
• Syphilis
• Malaria

Physical damage to the brain from things like traumatic head injuries can be another potential cause of psychosis. 

Support your mental health with therapy

Talk to a licensed therapist online

Preventative strategies for psychosis disorder

Many of the known or suspected causes of psychosis tend to be beyond the affected individual’s control. In general, there’s not much you can do about your genetics, your mother’s health while she was pregnant with you, or your childhood environment. 

Mental health strategies to prevent psychosis

However, taking certain precautions during adolescence or adulthood may reduce your risk of developing psychosis. This may be especially advisable if you know that you have a family history of psychotic disorders. Possible strategies include the following:

• Avoiding substances like cannabis and stimulants
• Maintaining healthy lifestyle habits, like a consistent sleep schedule, regular exercise, and nutrient-rich eating habits
• Practicing stress management techniques like deep breathing, progressive relaxation, and listening to soothing music
• Nurturing fulfilling social relationships
• Being aware of the warning signs of an impending psychotic break and seeking therapy and/or prescription antipsychotic medications if they arise

Seek help from a licensed mental health professional

Receiving regular psychotherapy from a licensed mental health professional may also be helpful. If you’ve had trouble finding a mental health care provider with whom you feel comfortable, you might want to consider internet-based therapy. Online therapy platforms can match you with a therapist whose demeanor and experience are well-suited to your needs.

Internet-based interventions as an effective treatment

Emerging evidence suggests that internet-based interventions may be an effective psychosis treatment. For example, a clinical trial of an online cognitive behavioral therapy (CBT) treatment found that online therapy typically reduced auditory hallucinations and social dysfunction. Similar kinds of psychotherapy might be useful for psychosis prevention. However, individuals who are currently experiencing acute psychotic symptoms may need to seek professional support in person.