Hallucinations and delusions affect roughly half of all people with Parkinson’s disease at some point during the illness, according to the Parkinson’s Foundation — making them one of the most common non-motor symptoms, yet one of the least discussed. Visual hallucinations are the most frequent form: seeing people, animals, or shadowy figures that aren’t there. Delusions — fixed false beliefs such as suspecting a partner of infidelity or believing strangers are in the home — are less common but often more disruptive. Several factors combine to cause these symptoms, including changes in brain chemistry from the disease itself, the effects of dopaminergic medications (especially dopamine agonists), sleep disturbance, and intercurrent illnesses such as urinary tract infections. The FDA has approved pimavanserin (Nuplazid) specifically for Parkinson’s-related hallucinations and delusions. Early recognition and a careful clinical evaluation — not just a medication adjustment — are key, because the cause is often treatable.

Medical disclaimer. This article is general information only. Hallucinations and delusions in Parkinson’s always warrant evaluation by the prescribing clinician — never adjust medications on your own. If a person becomes a danger to themselves or others, seek emergency care. See our Medical Disclaimer.

How common are hallucinations in Parkinson’s?

Estimates vary, but studies suggest that over the course of the disease, roughly half of people with Parkinson’s experience some form of hallucination or related visual phenomenon, according to the Parkinson’s Foundation. They are more common in older patients, in people with longer disease duration, and in people with cognitive changes.

Hallucinations can range from very mild — fleeting shadows at the edge of vision — to vivid, persistent, and frightening experiences. Delusions (fixed false beliefs) are less common but can be even more disruptive when they occur.

What Parkinson’s hallucinations typically look like

Visual hallucinations

These are by far the most common. People often see:

People — sometimes familiar, sometimes strangers, sometimes children.
Animals.
Shadows or movement at the edge of vision (often called minor hallucinations or “presence” experiences).
Patterns, faces, or objects that fade when looked at directly.

Early on, the person often realizes the image isn’t real — this is called retained insight. Later, insight can fade, and the experience feels real.

Auditory and other hallucinations

Less common but possible — hearing voices, music, or other sounds; or, rarely, smelling or feeling something that isn’t there. These warrant evaluation, particularly if persistent.

Delusions

Delusions are fixed false beliefs not easily corrected by reason. In Parkinson’s, the most common are:

Suspicion of infidelity in a long-term partner.
Belief that family members are stealing.
Belief that strangers are in the home.
Belief that the spouse is an imposter.

These can be very painful for everyone involved. They are not “bad behavior” — they are a symptom.

Why do hallucinations happen in Parkinson’s?

Several factors usually combine:

Changes in brain chemistry from the disease itself. Parkinson’s affects multiple neurotransmitter systems, not only dopamine. Changes in serotonin, acetylcholine, and other systems play a role in perception and cognition.
Medications. Dopaminergic medications — including levodopa and especially dopamine agonists — can contribute. So can anticholinergics, certain anti-anxiety drugs, and some sleep medications.
Cognitive changes. When mild cognitive impairment or dementia is also present, hallucinations are more common.
Infections, dehydration, or other illnesses. Urinary tract infections and pneumonia are notorious triggers in older adults.
Sleep disturbance. Poor sleep and vivid dreams can blur into waking hallucinations.
Sensory issues. Reduced vision or hearing makes hallucinations more likely.

This is why a careful evaluation — not just a medication adjustment — is so important when hallucinations appear.

What to do when hallucinations occur

In the moment

Stay calm. Even if it’s distressing, panic in the room makes the experience worse.
Don’t argue. Trying to convince someone the experience isn’t real rarely helps and often makes them feel attacked.
Acknowledge gently — “I know it’s frightening; I don’t see it, but I believe you” — and offer reassurance.
Redirect to something familiar and grounding — a glass of water, a different room, a familiar object, a few deep breaths.
Improve lighting; dim or shadowy rooms make hallucinations more vivid.
Reduce stimulation — turn down the TV, lower background noise.

Soon after

Write down what happened, when, and what may have triggered it.
Call the neurologist’s office and report — don’t wait for the next appointment if hallucinations are frequent, frightening, or persistent.
Look for treatable causes — a urinary infection, dehydration, a missed sleep, a new medication.
Keep the environment safe — secure medications, sharp objects, and any means by which the person could harm themselves or others.

How clinicians evaluate hallucinations

Standard evaluation usually includes:

A careful medication review — looking for recently added drugs, dose changes, and high-risk combinations.
Checking for infection, dehydration, electrolyte abnormalities, or other medical illnesses.
Cognitive screening for dementia.
Evaluating depression, anxiety, and sleep.
Considering whether anything has changed in vision or hearing.

How hallucinations are treated

Treatment is usually a layered approach:

Step 1: Find and treat triggers

Treat the urinary tract infection, address dehydration, fix sleep, simplify the medication list. This often resolves hallucinations on its own.

Step 2: Adjust Parkinson’s medications

The order in which neurologists typically reduce or stop medications when hallucinations are a problem (decisions made by the clinician, not the patient): anticholinergics first, then certain dopamine agonists, then amantadine, and finally — only if needed — adjusting levodopa. The goal is to keep enough medication for motor function while reducing hallucinations.

Step 3: Consider medications that help hallucinations

If step 1 and step 2 are not enough, neurologists may add medications such as pimavanserin (Nuplazid), which the FDA has approved specifically for hallucinations and delusions associated with Parkinson’s. Older atypical antipsychotics like quetiapine and clozapine are sometimes used. Most other antipsychotics — including haloperidol, risperidone, olanzapine, aripiprazole, and ziprasidone — should generally be avoided in Parkinson’s because they can worsen motor symptoms; this is something every clinician treating the patient should know.

Adding cholinesterase inhibitors (such as rivastigmine) may help if there are also cognitive changes.

What caregivers can do

Keep a hallucination diary — date, time, what happened, what was happening before, what helped.
Improve lighting, especially at dusk and at night.
Remove visual clutter, complex patterns on rugs or wallpaper, and reflective surfaces that can confuse.
Help the person sleep well; address pain, bladder issues, and overnight off periods with the neurologist.
Be the one who reports — patients often don’t.
Look after your own well-being. Caring for someone with hallucinations is exhausting, and burnout is real. See our future article on caregiver burnout (in the caregiver category).

When to seek urgent help

Threats or thoughts of harming self or others.
Severe agitation that can’t be calmed.
Fixed, persistent delusions that endanger the person (e.g., believing food is poisoned, refusing care).
Sudden severe confusion, especially with fever or other signs of infection.
A first-time hallucination in an older person with no prior history.

For any safety emergency, call your local emergency number.

Frequently asked questions

Are hallucinations a sign that Parkinson’s is worsening?

Often yes — they tend to appear later in the disease — but they can also appear because of an infection, a new medication, or another trigger that resolves. Don’t assume; have them evaluated.

Are they always caused by levodopa?

No. Levodopa can contribute, but anticholinergic drugs, dopamine agonists, infections, dementia, and sleep problems are all common contributors. Stopping levodopa is rarely the first step.

Should we hide medications from the person?

If delusions involve medications or the person is at risk of taking too much, yes — store medication securely and supervise dosing.

Can sensory issues mimic hallucinations?

Yes. Reduced vision (cataracts, macular degeneration) and reduced hearing can produce illusions and pareidolia (seeing meaningful patterns in random shapes). Make sure both senses are evaluated and supported.

Will hallucinations ever go away?

Mild ones often respond well to treatment of triggers and small medication adjustments. More persistent ones can usually be reduced significantly with the strategies above. With careful management, many families report meaningful improvement.

Sources

This article is general information only and is not medical advice. Please see our Medical Disclaimer and discuss hallucinations or delusions with the prescribing clinician promptly.

Hallucinations and Delusions in Parkinson’s: Causes, Triggers, and Treatment