Parkinson’s Disease Psychosis – Increased Disability and Caregiver Burden

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In my April 2015 blog, I discussed hidden symptoms including Parkinson’s Disease Psychosis (PDP).  This month, we take a closer look at this symptom complex and the increased disability and caregiver burden it can cause.

Parkinson’s Disease (PD) can cause multiple neuropsychiatric symptoms including anxiety, depression, psychosis, sleep disturbances, and cognitive impairment.  This suggests that PD may be described as a neuropsychiatric disease rather than a pure movement disorder.

The prevalence of PDP can be as high at 75% in patients with Parkinson’s Disease.  The most common PDP symptom, and one of the most disturbing to patients and caregivers, is visual hallucinations.  These hallucinations are more common in PD patients with dementia.  Visual hallucinations are often preceded by sleep disturbances including vivid dreams.  Visual hallucinations may include passage hallucinations (brief visions of a person or animal, passing sideways) and presence hallucinations (sensation of a person who is not there.  These hallucinations may include persons known to the patient, both living and deceased.  These clearly can be very disturbing to the patient.  As the disease progresses, auditory (voices), gustatory (taste), and olfactory (smell) hallucinations may also occur.

Another disturbing symptom of PD extends beyond formed visual hallucinations and illusions.  The content of delusions are often paranoid and centered on mistaken beliefs of infidelity and abandonment.  These delusions often involve family member, increase caregiver stress, and may include

  • Fregoli syndeome: a rare disorder in which the patient holds a belief that different people are in fact a single person who changes their appearance or is in disguise
  • Capgras syndrome: a delusion that someone has been replaced by an identical-looking imposter

Risk factors for PDP include advanced age, severity and duration of PD, depression, cognitive impairment/dementia, infections, dehydration, fever, medications, and sleep disturbances.

Many of the medications used to treat the movement symptoms of PD may actually trigger or worsen PDP symptoms.  When this occurs, health care professionals, including a pharmacist, must collaborate to find the right combination of medications to optimize control of movement symptoms and minimize the emergence of PDP symptoms.  While antipsychotic drugs may reduce PDP hallucinations, they may also worsen movement symptoms and should be used sparingly.



  1. Isaacson, SH Parkinson’s Disease Psychosis – A Symptom Complex Signaling Risk for Increased Disability and Caregiver Burden US Neurology 2015:11(1) 23-6