Risk factors for Parkinson’s psychosis

Last updated Feb. 24, 2025, by Lindsey Shapiro, PhD
Fact-checked by Patrícia Silva, PhD

While it’s not possible to predict if a person with Parkinson’s disease will develop psychosis, which is a group of symptoms that makes it difficult to know what’s real from what isn’t, there are certain risk factors that make developing the condition more likely.

Parkinson’s psychosis risk factors include advancing disease, older age, cognitive issues, sleep and mood disorders, genetics, and taking certain Parkinson’s medications. Anyone with Parkinson’s may develop Parkinson’s psychosis, however, meaning these risk factors alone don’t determine it.

The thought of having psychosis at some point can be very distressing. And while there isn’t any guaranteed way to prevent Parkinson’s psychosis, making certain lifestyle changes may help lessen your risk.

Staying in close contact with your doctor about your health is the best way to manage risk factors and the potential impact of psychosis on your life.

Risk factors for Parkinson’s psychosis

Parkinson’s psychosis is marked by symptoms such as hallucinations, or perceptions of things that are not real, and delusions, which are irrational views not rooted in reality. Disease-related structural or neurochemical brain changes and the use of certain Parkinson’s medications — which affect important brain signaling pathways — are believed to be among the causes of Parkinson’s psychosis.

While not all people with Parkinson’s develop psychosis, it’s relatively common and thought to affect more than half of people with Parkinson’s. Scientists are still learning more about what drives psychosis and influences its onset. So far, they’ve identified several different risk factors.

Disease progression

Parkinson’s psychosis can happen at any time, but more commonly occurs in advanced disease stages. Having Parkinson’s for a longer time has been identified as a risk factor for psychosis. Moreover, studies have associated more severe Parkinson’s motor symptoms — generally reflective of more advanced disease — with a risk of psychosis.

There may be multiple factors at play. As a neurodegenerative disease, neurological changes in Parkinson’s tend to get worse over time, increasing the risk of psychosis as the disease advances. Moreover, people with advanced Parkinson’s are more likely to have taken Parkinson’s medications that have been linked to psychosis for a longer period of time or at higher doses.

Medications

Parkinson’s medications, especially ones that increase the neurotransmitter dopamine or reduce acetylcholine, are associated with Parkinson’s psychosis. Taking these medications, especially if it’s for the first time or the dose is being changed, could increase your risk of developing psychosis.

Some over-the-counter medications, such as certain allergy and pain medications can also trigger episodes of psychotic symptoms, called delirium, so their use might make Parkinson’s psychosis more likely. Substances such as alcohol have also been associated with an increased risk of psychosis.

Cognitive decline, dementia, and sensory impairments

Cognitive changes in Parkinson’s can affect the way you think, remember, and make decisions. This in turn can influence how you perceive things around you and interpret your interactions with others.

People with Parkinson’s who experience cognitive decline are found to be at a higher psychosis risk. Dementia, an advanced stage of cognitive impairment, is considered a particularly strong risk factor.

Brain changes from Parkinson’s may affect your vision or hearing, increasing the risk of having psychosis symptoms such as hallucinations.

Sleep and mood disorders

Sleep disorders are a common group of nonmotor Parkinson’s symptoms and people with Parkinson’s psychosis are commonly found to have sleep issues. Sleep problems that may increase psychosis risk include:

• REM sleep behavior disorder, where a person acts out their dreams
• sleep apnea, where breathing intermittently starts and stops during sleep
• vivid dreaming
• other sleep disturbances.

It’s possible that changes in the basic cyclical pattern of sleep could cause dream-related imagery to appear in daily life, leading to hallucinations. Moreover, sleep problems in Parkinson’s can worsen cognitive dysfunction, further contributing to a risk of psychosis.

Mood disorders, including depression and anxiety, are other common nonmotor Parkinson’s symptoms that are associated with an elevated risk of psychosis. While it’s not fully understood, this might be related to common neurochemical imbalances or the effects of mood problems on other risk factors such as sleep and cognition.

Getting older

Age is another factor that might influence psychosis risk, with a number of studies finding that being older at the time of a Parkinson’s diagnosis is associated with a higher risk of developing symptoms such as hallucinations.

Late-onset Parkinson’s, which is when symptoms appear after age 50, has also been associated with an increased risk of psychotic symptoms.

There are a number of factors that could affect this, including sensory, cognitive, or other brain changes that happen with aging.

Genetic and environmental factors

Studies have identified possible genetic risk factors that may increase susceptibility to Parkinson’s psychosis, but they generally have not been well established. More research is needed to understand how genetic mutations contribute to developing psychosis.

A few genes that have been connected to Parkinson’s psychosis include:

• apolipoprotein E (APOE), a gene also closely linked to Alzheimer’s disease
• cholecystokinin (CCK), involved in brain and gut function
• dopamine-related genes, including transporters (DAT), receptors (DRD), and genes involved in dopamine metabolism (COMT)
• glucocerebrosidase (GBA), which is also a risk gene for developing Parkinson’s.

In some cases, episodes of Parkinson’s psychosis are also triggered or worsened by environmental factors, including:

• infection, illness, or injury
• dehydration
• nutritional imbalances or vitamin deficiencies
• stress.

Mitigating the risk of psychosis

It can be stressful to know you have risk factors for Parkinson’s psychosis, especially when you don’t have control over many of them. Still, for some of them, there are changes that can be made to help lower your risk of Parkinson’s psychosis, including:

• letting your doctor know if you notice anything unusual when taking your Parkinson’s medications, especially after just starting them or a dose change; they may need to adjust your treatment regimen to prevent psychosis as a side effect
• practicing good sleep hygiene, including keeping a regular sleep schedule
• monitoring your mental health and letting your doctor know if you start feeling depressed or anxious
• avoiding possible triggers for delirium, for example by maintaining good nutrition and staying hydrated, managing stress, and avoiding infection or illness by regularly washing your hands and staying away from people who are sick.

Support brain health and cognition by following the general healthy lifestyle recommendations for all adults, such as eating a good diet and exercising as suggested by your doctor.

There’s no guarantee making lifestyle changes will prevent you from developing Parkinson’s psychosis, but knowing you’ve taken the steps to minimize your risk and live as healthy as possible can give you peace of mind as you navigate life with Parkinson’s disease.

Maintaining an open line of communication with your doctor and letting them know about any changes you notice in your physical or mental function is critical for minimizing the risk of Parkinson’s psychosis onset or progression. They’ll be able to evaluate you and come up with the right management plan if any warning signs arise.

Managing psychosis

While you might not be able to prevent Parkinson’s psychosis from happening, appropriately diagnosing and treating it can help minimize its impacts on your life.

There is no established treatment regimen for Parkinson’s psychosis, but managing it may involve adjusting medications or addressing other underlying triggers, starting on antipsychotic medications, or cognitive-behavioral therapy. Once diagnosed, you’ll work closely with your doctors to come up with a plan that makes sense in your case. They can also help develop strategies you and your caregivers can implement in daily life to help manage your symptoms of psychosis.

In the long term, a significant aspect of managing Parkinson’s psychosis is in finding ways to maintain your mental and emotional health. Identifying healthy coping mechanisms, such as support groups or hobbies, can make it easier to deal with Parkinson’s psychosis and allow you the best possible quality of life.

Parkinson’s News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.