Neuropsychiatric differences between Parkinson's disease with dementia andAlzheimer's disease

Objective. To compare the profile of neuropsychiatric symptoms in patients with Parkinson's disease with dementia (PDD) and patients with Alzheimer's disease (AD). Design. Cross-sectional survey of a population-based sample of patients wit h PDD and AD patients matched for age, sex, and Mini-Mental State Examinati on (MMSE) score. Method. Patients were diagnosed according to published criteria for PD and AD. The diagnosis of dementia in PD was made according to DSM-III-R, and wa s based on clinical interview of the patient and a relative, psychometric t esting (including MMSE, Dementia Rating Scale and tests assessing memory, e xecutive functions and visuospatial functioning) and physical examination. The Neuropsychiatric Inventory (NPI) was administered to all patients. Results. One or more psychiatric symptoms was reported in 95% of AD and 83% of PDD patients. Hallucinations were more severe in PD patients, while abe rrant motor behavior, agitation, disinhibition, irritability, euphoria, and apathy were more severe in AD. In PDD, apathy was more common in mild Hoeh n and Yahr stages, while delusions increased with more severe motor and cog nitive disturbances. In PDD, only delusions correlated with the MMSE score. Conclusions. Neuropsychiatric symptoms are common and severe in patients wi th PDD, with important implications for the management of these patients. A D and PDD patients have different neuropsychiatric profiles, suggesting dif ferent underlying mechanisms. Cognitive impairment, psychopathology, and mo tor features progress independently in PDD patients Copyright (C) 2001 John Wiley Br Sons, Ltd.