A specialty in the practice of medicine that focuses on the relationships between neurological diseases and damage and psychiatric symptoms such as psychosis, executive dysfunction, language disorders, and dementia. It is sometimes erroneously used interchangeably with neuropsychology, a complementary field, which, though very similar, is based in the profession of psychology and, hence, has less of a focus on neurochemistry and pharmacology. Practitioners of neuropsychiatry are physicians who have completed a residency in neurology or psychiatry and, usually, additional training in the form of a fellowship. Symptoms often accompany neurode-generative diseases and will significantly affect about a third of people who have Parkinson’s disease. The physical deterioration that takes place in the brain with Parkinson’s disease causes changes in many brain functions such as cognition and memory. Providing treatment to relieve these symptoms requires understanding and addressing the underlying changes as well as the symptoms themselves. Many antIpsychotIc medications taken to treat psychiatric symptoms can cause the neuromuscular symptoms of Parkinson’s disease to worsen.