An Overview of Parkinson’s Disease Hallucinations

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Along with Parkinson’s disease symptoms like stiffness and tremors, delusions and hallucinations are common symptoms that can develop as the disease progresses.

Learn more about Parkinson’s hallucinations, what causes the symptoms, and how they are treated.

A senior man with Parkinson’s disease holds his arm with a hand, trying to eat a soup

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What Are Parkinson’s Hallucinations?

Symptoms of psychosis occur in up to 50% of people with Parkinson’s disease.

Parkinson’s disease psychosis is considered a neuropsychiatric condition. This means it involves neurology (the nervous system) and psychiatry (mental and behavioral health). While the psychosis involves mental health symptoms, they are caused by Parkinson’s disease, which is a disease of the nervous system.

Psychosis in Parkinson’s disease comes in two forms:

  • Hallucinations: Sensory experiences that are not really happening
  • Delusions: False beliefs not based on reality

These symptoms can be debilitating and scary for the people experiencing them. They can interfere with a person’s ability to care for themselves and to relate to other people.

Psychotic symptoms in Parkinson’s disease are associated with increased caregiver distress, risk of hospitalization and nursing home placement, and healthcare costs.

A study suggests the presence of hallucinations and delusions in people with Parkinson’s disease is a predictor of mortality (death).

Types of Hallucinations in People With Parkinson’s Disease

Hallucinations involve the five senses: sight, smell, touch, hearing, and taste.

People with hallucinations have sensory experiences that feel real to them, but are not actually happening and are not apparent to anyone else.

Types of hallucinations include:

  • Visual: Seeing things
  • Olfactory: Smelling things
  • Tactile: Physically feeling things
  • Auditory: Hearing things
  • Gustatory: Tasting things

For people who experience Parkinson’s-related hallucinations, the hallucinations are usually visual. They are typically non-threatening, but less commonly they can be of a threatening nature.

Often people with Parkinson’s disease psychosis see small people or animals, or loved ones who have already died. They are not interacting with them, just being observed.

Auditory hallucinations are more common in people with schizophrenia, but can happen (rarely) with Parkinson’s disease. With Parkinson’s disease, auditory hallucinations are usually accompanied by visual hallucinations.

More specific types of hallucinations experienced by people with Parkinson’s disease include:

  • Passage hallucinations: Something or someone seen briefly passing in the periphery of the vision (“corner of their eye”)
  • Illusions: A real object is briefly misperceived as something else—thinking a pile of clothes on the floor is a dog, the perception of faces of people or animals in irrelevant visual stimuli, seeing stationary objects as moving, etc.
  • Presence hallucinations: Feeling the presence of someone (person or animal) nearby—sometimes the presence is nonspecific, sometimes recognizable as someone they know
  • Complex visual hallucinations: Almost always involve people and animals, often in vivid detail—for example, scenes of elaborately dressed Victorian women or small children playing; happen more often in the evening and usually in the person’s own home

What Are Parkinson’s Disease-Related Delusions?

Delusions are false beliefs that are not based on reality. These beliefs are fixed. People experiencing them are unlikely to change or abandon these beliefs, even when presented with evidence that they are false.

Delusions experienced by people with Parkinson’s disease are usually of a common theme. These may include:

  • Spousal infidelity
  • Thinking that people are stealing their belongings
  • Thinking people are trying to harm them
  • Thinking people may put poison in their food
  • Thinking people are switching out or substituting their medications
  • Other beliefs based on paranoia

The Cause of Parkinson’s Delusions and Hallucinations

Some risk factors associated with the development of psychosis in Parkinson’s disease include:

  • Age: Parkinson’s disease usually occurs in people over age 60.
  • Duration and severity of Parkinson’s disease: Psychosis is more common in advanced or late-stage Parkinson’s disease.
  • Later onset: Occurring later in life
  • Hyposmia: A decreased sense of smell
  • Cognitive impairment: Problems with thinking, including trouble remembering, difficulty learning new things, difficulty concentrating, problems making decisions that affect everyday life
  • Depression: People who have both depression and Parkinson’s disease are at a greater risk of developing psychosis.
  • Diurnal somnolence: Daytime sleepiness
  • REM sleep behavior disorder: A sleep disorder in which you physically act out dreams; involves making vocal sounds and sudden, often extreme, arm and leg movements during REM sleep
  • Visual disorders: Impaired vision
  • Severe axial impairment: Speech, swallowing, balance, freezing of gait
  • Autonomic dysfunction: Impairment of the autonomic nervous system (ANS), which controls involuntary or unconscious actions such as heart rate, breathing, body temperature, blood pressure, digestion, and sexual function
  • High medical comorbidity: The existence of more than one condition or illness in the same person at the same time; with Parkinson’s disease, may include conditions such as dementia, depression, and sleep disorders

Medications

The use of certain medications are highly associated with the development of psychosis in people with Parkinson’s disease.

Dopamine Therapy

Dopamine agonists such as carbidopa-levodopa (Sinemet) are commonly used to treat Parkinson’s disease. This therapy helps improve motor symptoms in patients with Parkinson’s disease by increasing dopamine levels. The increase in dopamine levels can cause chemical and physical changes in the brain that may lead to symptoms such as hallucinations or delusions.

Anticholinergic Drugs

Anticholinergics decrease the activity of acetylcholine, a neurotransmitter that regulates movement. They can help with tremors and dystonia (involuntary muscle contractions causing slow repetitive movements or unusual postures). Their use, particularly in people over 70, has been associated with psychosis in people with Parkinson’s disease.

Types of anticholinergics include:

  • Benztropine (Cogentin)
  • Trihexyphenidyl HCL (formerly Artane)
  • Diphenhydramine (Benadryl)

Other medications, including some used to treat Parkinson’s disease, which may affect psychosis include:

  • Amantadine (Gocovri)
  • MAO-B inhibitors (selegiline, rasagiline, zelapar, others)
  • Entacapone (Comtan)
  • Pain medications
  • Muscle relaxants
  • Benzodiazepines (valium, Ativan, clonazepam)

What Should Be Examined Before Making a Diagnosis of Psychosis in Parkinson’s Disease?

Symptoms of psychosis in Parkinson’s disease can be temporary, reversible, and/or caused by factors not related to Parkinson’s disease.

When a person with Parkinson’s disease is experiencing symptoms of psychosis, other factors should be considered, including:

  • Urinary tract infection
  • Pneumonia
  • Current medications (including possible side effects and interactions)
  • Other conditions which may cause psychosis (such as severe depression)
  • General health

Ways to Treat Parkinson’s Hallucinations

Medications

Before starting a medication to treat Parkinson’s disease hallucinations, a healthcare provider may adjust or stop current medications the person is on if they are suspected of causing or contributing to the psychosis.

Antipsychotic medication such as clozapine (Clozaril) or quetiapine (Seroquel) may be used to treat psychosis in people with Parkinson’s disease. They are typically prescribed in low doses, and there are some concerns about their safety and efficacy to be considered.

A 2016 study indicated clozapine was the only antipsychotic with clear evidence regarding efficacy in people with Parkinson’s disease. Despite this, healthcare professionals are reluctant to prescribe it because of possible side effects and the need for blood count monitoring.

The study highlighted the lack of evidence that other antipsychotic drugs are effective. It indicated the presence of intolerable adverse effects and the increased risk of mortality associated with the use of antipsychotics in people with Parkinson’s disease who are experiencing psychosis.

These findings show the need for nonpharmacological strategies and the development of medications to meet the needs of people with psychotic symptoms and Parkinson’s disease.

In 2016, the Food and Drug Administration (FDA) approved pimavanserin (Nuplazid). This medication was the first drug approved to specifically treat hallucinations and delusions associated with psychosis in people with Parkinson’s disease.

This selective serotonin inverse agonist targets serotonin receptors rather than blocking dopamine, as other antipsychotics do.

Nonpharmaceutical Treatments

While psychoeducation and cognitive behavioral therapy (CBT) have been shown to help people with schizophrenia, they have not specifically been studied for use with Parkinson’s disease psychosis.

Helping a Person With Parkinson’s Disease Who Is Experiencing Hallucinations

Some ways for loved ones and caregivers to help a person while they are experiencing hallucinations include:

  • Stay calm and try to minimize anxiety and stress.
  • In some cases, it can help to let the person know that you cannot see, hear, etc. what they do, and help them understand it isn’t real.
  • Many times, questioning or doubting the hallucination may create more distress (it is very real to them), and going along with the hallucination is better than refuting it—for example, asking the person they are seeing to leave, and leading them outside instead of saying there is no one there.
  • Try distraction, such as changing the subject or moving with the person to another room.
  • Reassure the person that they are safe.
  • Be mindful of mirror placement.
  • Keep the environment well lit and as free of shadows as possible.
  • Take note of what is happening when the hallucinations happen, such as time of day, what the person was doing, where they were, etc.
  • Facilitate a discussion with the person’s healthcare provider about the hallucinations or odd behavior you have noticed. They may not realize they are hallucinating, or they may not tell you they are.
  • Secure items that may be dangerous to the person or others, including firearms, kitchen knives, tools, car keys, or other objects that could be used in an unsafe way.
  • Make sure the person can’t leave the house unnoticed or unsupervised, if appropriate.

Frequently Asked Questions

At what stage of Parkinson’s disease do hallucinations begin?

Psychosis is more common in advanced or late-stage Parkinson’s disease.

How can you improve aggressiveness and hallucinations in Parkinson’s?

Hallucinations may spark anger or aggression in a person with Parkinson’s disease. Some ways to help include:

  • Reassure them, tell them they are safe.
  • Speak slowly and calmly.
  • Ask questions about the person’s feelings.
  • Listen to the person, don’t interrupt.
  • Avoid sudden movements.
  • Give the person space and a way out, so they don’t feel cornered or threatened.
  • Make an “emergency plan” ahead of time for what you and others in the house will do if the person experiencing hallucinations becomes a danger to themselves, you, or anyone else.
  • When it is safe, help the person speak with their healthcare provider about making a plan to address the hallucinations.

What percentage of people with Parkinson’s have hallucinations?

Symptoms of psychosis occur in up to 50% of people with Parkinson’s disease.

People with Parkinson’s disease who have psychotic symptoms may experience hallucinations (sensory experiences, usually visual, that are not really happening) or delusions (false beliefs that are not based on reality).

A Word From Verywell

Hallucinations are a common but frightening experience for people with Parkinson’s disease. Thankfully, they can be managed and in some cases reversed.

If you or a loved one is living with hallucinations due to Parkinson’s disease, speak with a healthcare provider. Making medication adjustments, introducing new medication, and addressing other possible underlying causes can go a long way in reducing psychosis associated with Parkinson’s disease.

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10 Sources
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