Parkinson's disease can also affect changes in thought, behavior and judgment

Parkinson's disease affects 6.3 million people worldwide. While the disease is recognized for its profound effects on movement, up to 40 percent of Parkinson's disease patients also develop changes in thought, behavior and judgment.

As Parkinson's disease progresses, patients may experience what is called 'Parkinson's Psychosis,' in which they experience changes in thought, behavior and judgment. In more advanced stages these symptoms include hallucinations where patients see, hear or feel things that aren't really there, and paranoid delusions where they become distrustful of even their closest friends and family members. The emergence of these symptoms represents a major turning point in the course of the patient's disease.

"While the physical manifestations of Parkinson's disease are difficult to deal with, the changes in thought, behavior and judgment strain the bonds between patients and their caregivers and families," said Dr. Bernard Ravina, Director of the Movement and Inherited Neurological Disorders Unit at the University of Rochester in New York.

According to an on-line survey recently conducted by MediciGlobal, a global patient recruitment and retention specialty firm, over one-third of Parkinson's caregivers are unaware that changes in thought, behavior, and judgment can accompany the disease. "As a registered nurse, I was prepared for the physical problems with my husband's Parkinson's disease but, despite my job as a RN, I was totally unprepared for the psychiatric issues," said Carol McLain, a caregiver who took the survey.

According to Dr. Ravina, "It's the non-physical symptoms of the disease that are often most devastating for both the patient and caregiver. As the patient's mental health deteriorates, the family often has to make the painful and expensive decision of moving the patient into a nursing home."

There are currently no FDA-approved treatments for these particular non-physical symptoms of Parkinson's disease. Nevertheless, doctors often resort to the use of potent antipsychotic drugs to treat these symptoms even though these drugs sometimes have serious side effects, particularly in the elderly, including worsening of motor skills, excessive sleepiness, increased infections, stroke, and sudden death in some patients. As a result, there is a large unmet medical need for new and improved treatment options.