8 Facts You Need to Know About Psychosis From Parkinson’s Disease

by Lara DeSanto Health Writer

Parkinson’s disease (PD) is a brain disorder in which dying neurons (nerve cells) can cause symptoms ranging from tremors to mobility and balance issues. And while these movement problems are the cardinal signs of PD, the disease can have other effects, too—including psychosis. Psychosis, which can involve hallucinations, delusions, and confusion, affects between 20% to 40% of people with Parkinson’s, per the Parkinson’s Foundation. Keep reading to learn eight key facts about this complication, from causes to treatments.


Symptoms Range From Mild to Severe

“Generally speaking, psychosis is combination of two things: delusions, which are false beliefs, and hallucinations, which is when you’re seeing or hearing things that aren’t really there,” explains Jennifer S. Hui, M.D., a neurologist with Keck Medicine of University of Southern California in Los Angeles. People with mild hallucinations may see things like patterned wallpaper on an actual plain wall—and understand that it’s not reality. In more severe cases, people may experience intense paranoia, believing their spouses are cheating on them, or that people are trying to steal from them or harm them, says Dr. Hui.


PD Medications May Lead to Psychosis

If Parkinson’s disease is primarily a movement disorder, then why might psychosis occur? For some people, PD drugs may be the culprit, causing unwanted neurological effects. “Many of our medications can exacerbate and cause psychosis,” explains Dr. Hui. Many Parkinson’s meds work by increasing dopamine in the brain, which can help with movement symptoms of PD. But that same dopamine can also stimulate areas in the brain that lead to psychosis symptoms like hallucinations and delusions, according to the Michael J. Fox Foundation for Parkinson’s Research.


Or, Parkinson’s Itself May Lead to Psychosis

In other cases, the disease's progression, rather than its treatments, is likely at the root of psychosis, says Ling Pan, M.D., clinical assistant professor of neurology and neurosurgery at NYU Langone Health in New York City. “Psychosis can be symptom of Parkinson’s itself, so patients, for example, who have not been on medications [who] you track the natural course of their disease may develop psychosis as part of the disease pathology.” However, it appears PD medications do increase the risk, she adds.

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Families Often See the Signs First

Often, loved ones or close family members may notice the signs of psychosis in Parkinson’s disease first. “Diagnosis is based on history, often with patients’ families reporting that symptoms are occurring,” says Dr. Hui. To confirm the diagnosis, your doctor will consider a variety of diagnostic criteria, such as which specific symptoms are present and when they began, as well as ruling out other potential causes, according to a study in Parkinson’s Disease.

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Treatment Not a Must Early On

Typically, people with PD who develop psychosis don’t do so until five to 10 years into their disease course, Dr. Hui says. For some, particularly early on, mild psychosis symptoms may be manageable without treatment. “If the hallucinations are very mild and fleeting, we may not treat it if the patient is aware it is not real and can pretty much ignore them,” she explains. “We start treating when hallucinations [or delusions] become more severe or scary, like seeing attackers, or thinking someone is breaking in, and it interferes with activities of daily living or is emotionally distressing.”

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Changing Up Meds Can Help

If psychosis in PD does require treatment, the first thing your doctor will do is to consider altering your Parkinson’s medication regimen, since some drugs can make psychosis symptoms worse. “The first step is to evaluate how much medication the patient is on. And, if they're on high doses of medication, to reduce the medication burden [dose] and see if we can reach a happy medium between having them take enough medication to help their motor symptoms and still reduce the psychosis as a complication,” explains Dr. Pan.

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Additional Drugs May Be Helpful

In addition to reducing your PD dosages, or removing certain meds from your treatment, there may also be additional drugs to try. “If we reach a point where we’ve optimized medications and can’t reduce any further because otherwise we would have more motor dysfunction, there are other medications we can add on to specifically address psychosis,” explains Dr. Pan. There are three main options, she says, including Nuplazid (pimavanserin), which the FDA approved for psychosis in PD in 2016, plus antipsychotics Clozaril (clozapine) and Seroquel (quetiapine). Your doctor can determine what’s best for you.

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Lifestyle Changes Can Help

Beyond treatment with medications, other changes to your lifestyle may be helpful in managing psychosis symptoms in PD, says Dr. Pan. For example, increasing time spent with friends and engaging with others both help brain health in general, and may help reduce cognitive complications and psychosis in Parkinson’s patients, says Dr. Pan. “Also, a regular routine is important, such as keeping a regular sleep schedule, which can help with preventing psychosis and cognitive health, in general.” Exercise is also protective in slowing the progression of Parkinson’s, she adds.

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The Bottom Line on PD Psychosis

While it can be tricky to balance treating your motor symptoms of Parkinson’s disease with treating symptoms like psychosis, working closely with your health care team can help you find the right combination of medications and lifestyle management skills for you. And remember: As with many aspects of this disease, early intervention is best. “Psychosis in Parkinson’s disease is something that, as providers and family members, [is] important to screen for early on so we can monitor it,” says Dr. Pan.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at WTOP.com.