Between 20% and 30% of people with Parkinson’s are reported to see things that are not actually there (hallucinations), or to hold firmly to beliefs that are not true (delusions). Clinicians group these symptoms together under the name Parkinson’s disease psychosisThe umbrella term for hallucinations and delusions that occur in Parkinson's. Parkinson's medications, dementia and sudden changes in awareness (delirium) are considered the main causes.Learn more.
Why it happens
Often the cause is the Parkinson’s medications themselves, such as levodopa or dopamine agonists. The same drugs that raise dopamine to control motor symptoms can, at the same time, push things in the direction of hallucinations and delusions. Beyond medication, dementia or a sudden change in awareness (delirium) can also be behind it.
What it looks like
The most common form is a brief visual hallucination of a person or an animal. Among delusions, the ones most often reported are suspecting a spouse of infidelity or believing that someone intends to cause harm (jealousy and persecutory delusions), and these also tend to be harder to treat. Delusions like these can lead to aggressive behavior, which can affect the safety of both the person and the family.
How to respond in the moment
- Don’t argue or try to talk the person out of it. Insisting “there’s nothing there” usually doesn’t help and can increase distress instead.
- Stay calm and reassuring.
- Go along with it rather than denying it, then redirect attention. For example, if someone says they see a cat, “I’ll put the cat outside” works better than “there is no cat.”
- Keep dark areas well lit. Visual hallucinations are known to come more easily in the dark or when vision is unclear. Lighting up dim spaces such as hallways is particularly helpful.
- Plan some light activity for the evening. Symptoms tend to show up more during quiet evening hours when there is little going on.
Ordinary antipsychotics need care
Hallucinations and delusions bring to mind the antipsychotic medications used in psychiatry, but most standard antipsychotics work by blocking dopamine, which risks making Parkinson’s motor symptoms worse instead. That is why, for people with Parkinson’s, medications with weaker dopamine-blocking action such as quetiapine and clozapine are often considered first. Clozapine is regarded as the most effective, but it can lower white blood cell counts, so regular blood tests are needed. Pimavanserin, which has almost no effect on dopamine, is also used as a medication specifically for Parkinson’s disease psychosis. These are judgments that call for specialist expertise, so if any other doctor or specialty has prescribed you a medication, be sure your Parkinson’s care team knows about it too.
Tell your care team even if it doesn’t bother you
Even if hallucinations or delusions don’t trouble you, you should still tell your care team. They can be a sign that medication needs adjusting, and left alone, delusions may get worse or lead to safety problems. Family members often notice the symptoms first, so it also matters that a care partner passes on what they have observed.
This article is not a substitute for medical diagnosis or treatment. If you experience hallucinations or delusions, please talk with your care team.
