Article written by
Alison Channon

• Hallucinations and delusions are relatively common among people with Parkinson’s disease.
• Hallucinations and delusions are more likely to occur in advanced Parkinson’s.
• Understanding the different types of hallucinations and delusions can help you better recognize them.

Hallucinations and delusions are two symptoms of Parkinson’s psychosis. Parkinson’s disease is a degenerative condition affecting the central nervous system (brain and spinal cord). Parkinson’s disease psychosis is one of the nonmotor symptoms of the condition. Motor symptoms include tremors, muscle stiffness, slowed movements, and loss of balance.

Hallucinations and delusions are fairly common among people with Parkinson’s — between 20 percent and 40 percent of individuals with Parkinson’s disease report experiencing them. However, they can sometimes be challenging to identify for those experiencing them and for caregivers and loved ones. Understanding how hallucinations and delusions manifest and when they are more likely to occur can help people with Parkinson’s disease and their loved ones better recognize them.

What Are Hallucinations and Delusions?

Hallucinations occur when a person sees, hears, feels, smells, or tastes something that isn’t actually there. Hallucinations happen when a person is awake — they are not dreams. People may be aware that they are experiencing a hallucination while it’s happening or realize it shortly after. This is called “retaining insight.” Losing insight — failing to realize something is a hallucination — can cause agitation and can also lead to falls or other accidents. “I acted out on many of my hallucinations,” one MyParkinsonsTeam member wrote. “One time I fell forwards, flat on my face, in an intersection!”

The Parkinson’s Foundation describes delusions as “illogical, irrational” and “persistent thoughts not based in reality.” Delusions are less common than hallucinations — about 1 in 10 people with Parkinson’s disease experience delusions. Delusions can be particularly challenging for family members and caregivers because a person with Parkinson’s may falsely believe someone is harming them. Delusions can also lead to unsafe behavior. A woman on MyParkinsonsTeam who cares for her mother wrote, “I have to take things away because she plays with things that can be dangerous. She tries putting things in outlets that don't belong.”

The precise reasons for Parkinson’s psychosis are not fully understood. Parkinson's psychosis may be a symptom of advanced Parkinson’s disease or a side effect of long-term use of dopamine treatments (called dopaminergic drugs). The likelihood of experiencing hallucinations and delusions increases the longer a person lives with Parkinson’s.

If hallucinations are experienced during the early stages of Parkinson’s, they could be a sign of dementia with Lewy bodies (DLB). DLB is a movement disorder that shares features of Parkinson’s. Differentiating between the two conditions can be challenging because of their many similarities.

Both Parkinson’s disease and DLB can lead to dementia. However Parkinson’s disease dementia typically begins at least one year after movement problems develop, whereas dementia in DLB coincides closely with movement symptoms.

Recognizing Types of Hallucinations

Hallucinations are not limited to visions. People with Parkinson’s can hear something that isn’t there and even smell or taste something that isn’t there. Hallucinations can be categorized by the senses involved.

Visual Hallucinations

Visual hallucinations are common in Parkinson’s psychosis. People can have visions in black and white or in color that last a few seconds or much longer. Visual hallucinations often involve animals or people, such as a child or deceased family member. People often experience hallucinations in their peripheral vision and in low-visibility situations or dark lighting.

Members of MyParkinsonsTeam share examples of their visual hallucinations:

• “I started having hallucinations a few nights ago. There was a cat crawling around the living room and climbing on furniture.”
• “I see the random cat or rabbit pop out when walking through the house. I've momentarily thought there was someone in my yard.”
• “When I'm sitting at my desk, I wear glasses and in my peripheral vision to the left side of my head I see people standing next to me as I am seated. It's not the same person. It could be a teenage boy or an adult woman.”

Auditory Hallucinations

Auditory hallucinations occur when a person hears a sound that isn’t actually there. They happen less frequently than visual hallucinations. People often report hearing indistinct sounds, like music playing in another room.

MyParkinsonsTeam members share examples of auditory hallucinations:

• “My husband had an auditory hallucination last night for the first time. He got into his wheelchair and went looking for water that he ‘heard’ running.”
• “I kept hearing a faint repetitive alarm in my head, just like my alarm. Checked the cell phone alarm to make sure I had turned it off.”
• “Hearing a radio, TV, or something and absolutely KNOW there is nothing on? This is almost a constant thing for me. The upside for me is it’s music, although it’s hard to make out the tunes most of the time.”

Olfactory, Tactile, and Gustatory Hallucinations

People with Parkinson’s disease can also experience olfactory (smell), tactile (feel), and gustatory (taste) hallucinations. These types of hallucinations are less common than visual and auditory hallucinations.

Smelling cigarette smoke is an olfactory hallucination several members of MyParkinsonsTeam describe:

• “I have, over the past few months, been having the issue of smelling smoke occasionally when there is none. It’s subtle and will last for about an hour.”
• “I can smell cigarette smoke; smelled it all day today and there is no one anywhere who smokes.”
• “It’s nice to hear I'm not alone in this. It’s just my hubby and me and neither of us smoke, nor does anyone we know, unless my cat is secretly lighting one up without my knowledge. LOL!”

Recognizing Symptoms of Delusions

People with Parkinson’s delusions frequently believe they are being mistreated. As a result, people experience paranoia, mistrust, anger, and anxiety. Jealousy delusions — usually a belief that a spouse is being unfaithful — are very common. Persecutory delusions — the false belief that someone is cheating or conspiring against you — are also common. Persecutory delusions are often directed at someone the person with Parkinson’s interacts with regularly, like a spouse, family member, or caregiver.

Caregivers on MyParkinsonsTeam share their experiences with jealousy and persecutory delusions:

• “Husband still thinks I'm slipping out at night, which I understand is the number one delusion for a spouse!”
• “He is saying I am lying to him and he is showing signs of being paranoid.”
• “They provoke severe anxiety in my husband and sometimes he believes men are after him. He can become distrustful of me and his health care aide, whom he likes very much. These bad episodes can last one hour or six hours.”
• “My mom tells me I don't feed her or I make her eat things that she doesn't like.”

Some delusions are more general confusions of reality. As one caregiver described, “He mixes reality and old memories and TV programs and fantasy to create a different kind of reality.” Another caregiver shared, “He is POSITIVE we are not where we are, that he has two cats, etc.”

A person experiencing delusions may be anxious, fearful, or very agitated. Caregivers explain how delusions impact their loved ones’ behavior:

• “He believes the delusion so strongly that it keeps him stressed. At times he won't eat, and he is having trouble sleeping.”
• “She gets agitated, asks where she is, and sometimes has intense moments of confusion and fear.”
• “My man friend, age 92 as previously mentioned, gets feisty and argumentative. It is extremely hard for me to keep a civil tongue. He's angry even when you accept his version of reality.”

Risk Factors for Parkinson’s Psychosis

Understanding the risk factors for hallucinations and delusions can help you recognize symptoms of Parkinson’s psychosis. The following factors may increase the likelihood of experiencing hallucinations and delusions:

• Advancing cognitive impairment, including worsening memory loss
• History of depression
• Blurry or double vision
• Hearing loss
• Sleep disorders and sleep disturbances
• Changes to medications
• Worsening medical conditions outside of Parkinson’s

“We have noticed that when my father had delusions, it's been when his general health is not good, or when he has been in the hospital for PD-related issues,” a MyParkinsonsTeam member commented.

Questionnaires used in a clinical setting can help assess the risk of developing hallucinations or delusions, or establish that they are occuring. These include:

• PD nonmotor symptom scale
• Parkinson Psychosis Questionnaire
• Scale for Evaluation of Neuropsychiatric Disorders in Parkinson’s Disease

Individuals with Parkinson’s or their caregivers can speak with a neurologist to understand if any of these tools would be helpful in their particular situation.

Managing Parkinson’s Psychosis

Addressing Parkinson’s psychosis may involve changes to medications. A neurologist or psychiatrist may recommend discontinuing certain medications or adding in an antipsychotic medication. Often, a doctor will recommend discontinuing anticholinergics — medications frequently used to treat tremors or dystonia. Always consult your doctor before making any changes to your medication routine.

A neurologist will also look at factors other than medication which may contribute to hallucinations or delusions.

Learn more about managing psychosis in How to Manage Hallucinations and Delusions.

By joining MyParkinsonsTeam, members gain a community of more than 67,000 people living with Parkinson's disease or caring for someone with Parkinson’s who understand their challenges, including hallucinations and delusions.

Read Member Spotlight: Hope for Those Experiencing Hallucinations and Delusions.

Here are some recent conversations on MyParkinsonsTeam about recognizing hallucinations and delusions:

• “Does anyone have issues with hallucinations dealing with smell?”
• “How long does post-surgical psychosis last?”
• “Has anyone had to deal with PD psychosis?”

Do you have any tips for recognizing hallucinations or delusions? Share your thoughts on MyParkinsonsTeam.

References

1. Hallucinations/Delusions — Parkinson’s Foundation
2. Parkinson Disease (PD) — Merck Manual
3. Hallucinations and Delusions — Parkinson’s Victoria
4. Psychosis: A Mind Guide to Parkinson’s Disease — Parkinson’s Foundation
5. Psychosis — American Parkinson Disease Association
6. How to Bring Light to the Darker Side of Parkinson’s: a Primer on Hallucinations and Delusions and How to Manage Them — Davis Phinney Foundation for Parkinson’s
7. Hallucinations and Delusions — European Parkinson’s Disease Association
8. Management of Psychosis in Parkinson’s Disease: Emphasizing Clinical Subtypes and Pathophysiological Mechanisms of the Condition — Parkinson’s Disease
9. Parkinson’s Treatment Tips on Psychosis and Hallucinations — University of Florida Health
10. Anticholinergic Drugs — Parkinson’s Foundation

Alison has nearly a decade of experience writing about chronic health conditions, mental health, and women's health. Learn more about her here.