Skip to Accessibility Tools Skip to Content Skip to Footer

Symptoms – Psychotic Symptoms

More than half of all people with Parkinson’s disease (PD) will develop psychotic symptoms. The most common psychotic symptoms seen in people with PD are hallucinations and illusions. Psychotic symptoms greatly affect the quality of life for both patients and caregivers. Psychotic symptoms are associated with an increased incidence of nursing home placement, as caregivers are unable to cope with the hallucinations and delusions. Psychotic symptoms are also associated with a higher risk of dementia and increased risk of death. Generally, psychotic symptoms develop several years after a diagnosis of PD. Because these symptoms are related to both psychiatry (the area of medicine focused on mental and behavioral health) and neurology (the area of medicine focused on the nervous system), psychosis with PD is considered a neuropsychiatric condition.1,2

Hallucinations in Parkinson’s disease

Hallucinations are seeing, hearing, or feeling something that is not actually there. Most hallucinations experienced in PD are visual, although some people experience auditory, tactile (touch), or olfactory (smell) hallucinations. Hallucinations occur when the person is awake—not sleeping or dreaming—and can occur at any time of day or night. They can be frightening, for the patient experiencing them as well as their caregiver. Generally, hallucinations are repetitive and last for a short duration.1,3

Delusions in Parkinson’s disease

Delusions are irrational, illogical views that are not based on reality. They usually involve jealousy, persecution, and/or abandonment. To the person experiencing delusions, they seem very real and cannot be controlled. A common type of delusion is paranoia, in which a person becomes highly suspicious. Delusions and paranoia may make the person with PD afraid of being poisoned by medications or food. A person experiencing delusions may also accuse their loved ones of trying to harm them. They may become argumentative, aggressive, or unsafe.1,3

Agitation in Parkinson’s disease

Agitation is a state of high anxiety, extreme restlessness, or excitement. Agitation may be a sign of psychosis in patients with PD, although it can also be associated with depression or anxiety, other non-motor symptoms of PD. Agitation is also used to describe restless motor symptoms of PD. 4,5

What causes psychotic symptoms in Parkinson’s disease?

Psychotic symptoms in people with PD are usually caused as a side effect of medications used to treat PD. All of the current PD medications can potentially cause psychotic symptoms. Hallucinations and delusions may also be caused by the chemical and physical changes that occur in the brain as a result of PD. 3

Managing psychotic symptoms in Parkinson’s disease

Any psychotic symptoms, such as hallucinations, delusions, or paranoia, that are experienced by a person with PD should be reported to a doctor, even if the symptoms are not bothersome. Managing these symptoms may include reducing or withdrawing the use of PD medications that may be causing the symptoms or adding an antipsychotic medication. Antipsychotic medications that may be used in people with PD psychosis include clozapine, quetiapine, and ziprasidone.1,2

Written by: Emily Downward | Last reviewed: March 2017
  1. Accessed online on 1/9/17 at
  2. American Parkinson Disease Association. Accessed online on 1/9/17 at
  3. National Parkinson Foundation. Accessed online on 1/9/17 at
  4. Parkinson’s Disease Foundation. Accessed online on 1/5/17 at and
  5. Aarsland D, Brønnick K, Ehrt U, De Deyn PP, et al. Neuropsychiatric symptoms in patients with Parkinson's disease and dementia: frequency, profile and associated care giver stress. J Neurol Neurosurg Psychiatry. 2007 Jan; 78(1): 36–42.