Parkinson's Psychosis: A Little-Known Symptom of PD


Shakiness, unsteady gait and freezing are the hallmark symptoms of Parkinson’s disease (PD), but half of those with PD also develop hallucinations, paranoid thinking and delusions. Parkinson's is a devastating and complex condition that interferes with movement. As it progresses, it produces a wide range of other troubling issues. One of the more serious, yet lesser-known, symptoms of this neurological condition is called Parkinson’s disease psychosis.

What is Parkinson's Psychosis

Parkinson’s disease psychosis is a common and very disabling non-motor feature of this disease. It is considered a neuropsychiatric condition, since it deals with mental health symptoms (hallucinations and delusions) caused by a disease of the nervous system (Parkinson’s disease). "Parkinson's patients have a substantial risk of eventually developing this problem,” says Richard B. Dewey Jr., MD, professor of Neurology and Neurotherapeutics and Director of the Clinical Center for Movement Disorders at the University of Texas Southwestern Medical Center.

Indeed, 50 percent of people with PD will experience an episode of psychosis at least once, usually in the form of a visual hallucination. Caregivers and patients alike often wonder what happens in the body to cause this debilitating symptom and how it can be prevented or minimized.

Causes of PD Psychosis

Researchers do not know precisely what causes psychotic symptoms in some PD patients, but there are certain risk factors that can play a role. A patient’s age, the length of time they have lived with PD, the severity of their other symptoms, and whether they are on medications that increase levels of dopamine in the brain can all play a part in the development of psychosis.

Many of the prescriptions used to treat the motor symptoms of PD do so by increasing the amount of dopamine in the brain. Unfortunately, elevated dopamine levels can contribute to psychotic behaviors.

Parkinson's Hallucinations, Paranoid Thoughts & Delusions

A psychotic episode typically involves seeing people and objects that are not there (visual), hearing noises that don’t exist (auditory) and delusions (inaccurate beliefs that the affected person nonetheless believes to be true). Delusions typically take the form of paranoid thoughts, such as a patient believing a that family member or friend has poisoned their food or that their spouse is cheating on them.

During the later stages of PD, these episodes may cause the patient to become more confused and affect their connection with reality. For example, a loved one with PD may no longer be able to distinguish personal experiences from the those of the outside world. Typically, psychosis does not develop until several years after one’s initial diagnosis of Parkinson’s, but keep in mind that there are other conditions that may mimic the symptoms of PD psychosis. Delirium and various forms of dementia can be confused with PD psychosis and vice versa.

Psychotic symptoms can be extremely disturbing to the person experiencing them and can create a challenging situation for all who are involved in providing care.

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Treatment Options for PD Psychosis

Treating psychosis is truly a challenge. Unfortunately, only 10 to 20 percent of people with PD psychosis actually inform their doctor of their symptoms. Dr. Dewey speculates that stigma and fear of embarrassment prevent many patients from seeking help.

When new symptoms of any kind arise, it is crucial to make a doctor’s appointment to discuss the issue. A physician will first try to determine whether there is an underlying illness (like a urinary tract infection) that could be causing psychotic behaviors. Treating the underlying cause (if there is one) is one of the simplest ways of minimizing these episodes.

When there is no other identifiable source, doctors often turn their attention to the medications that the patient is taking. Gradually decreasing the dosage of dopamine-enhancing medication may reduce psychotic symptoms, but the obvious trade-off is that the person’s motor function is likely to deteriorate more rapidly. Balancing risks and benefits is a delicate and complicated process that often involves a three-step approach, including assessment and planning, adjusting or reducing any medications, and initiating antipsychotic therapy.

Usually the last resort for managing the symptoms of PD psychosis is the use of atypical antipsychotics such as quetiapine (Seroquel) and clozapine (Clozaril). However, these medications may also worsen a patient’s motor symptoms. Only one medication specifically developed to treat PD psychosis is currently available: Nuplazid (pimavanserin). It was approved by the FDA in 2016. Nuplazid is unlike other atypical antipsychotics in that it targets serotonin receptors and may alleviate psychotic symptoms without affecting a patient’s motor function.

Medical research produces discoveries continually, so keeping an ongoing dialogue open with your loved one’s doctor should be a priority. Finding the best balance of treatment is crucial for optimum care and quality of life.

Potential Triggers of Psychotic Episodes

Psychotic symptoms can have many possible triggers, especially in older patients. A few contributing factors include sleep deprivation, metabolic or electrolyte imbalances, medications, and infections. Overall susceptibility is strongly associated with the patient’s mental status. These episodes are more likely to arise in situations where there is little stimulation, such as in the evenings or when a patient is alone in a quiet room.

As stated above, medications are often a culprit as well, since many prescribed for PD increase levels of dopamine in the brain. Parkinson’s disease is caused by a malfunction and loss of neurons that produce dopamine, a neurotransmitter which functions in relaying messages to the brain that control movement and coordination. Dopamine plays a pivotal role in hallucinations and delusions, but the progression of PD on its own can impair cognition and visual processing, which can lead to Parkinson’s disease dementia. According to the Alzheimer’s Association, 50 to 80 percent of those with Parkinson’s will eventually develop PD dementia.

How to Cope with Parkinson's Psychosis

Caregivers of people with PD and other neurological conditions that cause hallucinations and delusions can engage in a variety of behavioral interventions to keep their loved ones calm and in control during a psychotic event. However, the effectiveness of approaches like redirection and validation therapy depend on the severity and frequency of one’s episodes. While these techniques may prove helpful from time to time, Dr. Dewey believes that these efforts are generally unsuccessful over the long term. The best step is to notify your loved one’s doctor at the first sign of new or worsening psychotic symptoms to avoid unnecessary injury, stress and even placement in a long-term care facility.

It is important to maintain an honest relationship with your loved one, asking often about any abnormal ideas and experiences they may be having. Family members are usually surprised to learn that their loved one is experiencing these episodes, because many patients with PD are reluctant to divulge this information unless specifically asked.

Caregivers should also stay vigilant in observing the signs of impulse-control disorders, such as excessive gambling, hypersexuality, reckless spending, etc. These behaviors generally go undetected unless close family members know what to look for, or their physician specifically asks about them. Psychosis and impulse-control disorders are common complications of dopaminergic therapies that can have serious consequences if left undiagnosed or untreated.

Remember that not all PD patients will experience severe hallucinations or delusions. If your loved one seems to be doing well, exercise caution when any dosages are changed or medications are added or discontinued. Tweaking a medication regimen should ideally happen one change at a time in order to pinpoint positive and negative effects of a single variable.

Many activities and therapies can be included in a PD patient’s daily routine to minimize troublesome symptoms. Eating a healthy diet, exercising as much as possible despite limitations, and openly communicating with family members and physicians are all crucial parts of maintaining a high quality of life. Caregivers must be diligent about the safety of their loved one’s living environment, encourage interactivity and outings, and explore various movement and creative therapies. Keeping your loved one active is a key factor in their overall health and happiness.

Sources: Ravina B, Marder I(, Fernandez HH, et al. Diagnostic criteria for psychosis in Parkinson’s disease: report of an NINOS, NIMH work group. Mov Disord. 2007;22:1061-1068; Parkinson's Foundation (

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