Inclusion Criteria:  Any person who receives medical care for the diagnosis of Parkinson's disease with mild cognitive impairment (MCI) or dementia may be eligible to participate in the research database. There are no limitations for database participation based on age, disease severity or presence of cognitive impairments, as long as the person is able to complete the research assessments.  Exclusion Criteria:  Absence of Parkinson's disease diagnosis. There are no limitations for database participation based on age, disease severity or presence of cognitive impairments, as long as the person is able to complete the research assessments.