Introduction to Special Issue Psychiatric Aspects of Parkinson's Disease, Parkinson's Disease With Dementia, and Dementia With Lewy Bodies

Parkinson’s disease (PD), Parkinson’s disease with dementia (PDD), and dementia with Lewy bodies (DLB) are common neurological disorders with prominent neuropsychiatric symptoms. Assessment, investigation, and treatment of the neuropsychiatric dimension of these disorders are important to improve the quality of life of patients and their caregivers as well as to provide insight into the basic neurobiology of neuropsychiatric disorders occurring in the context of neurological disease. In the recent past, there has been rapid progress in understanding the neuropsychiatric manifestations of PD, PDD, and DLB. All of these disorders are alpha-synucleinopathies and all share common features. Increasingly it appears that PDD occupies one end of the spectrum of PD emerging as Lewy bodies become abundant in the cerebral cortex. These patients meet pathologic criteria for DLB creating systematic links among PD, PDD, and DLB. In this special issue in the Journal of Geriatric Psychiatry and Neurology, leading researchers provide updates on the neuropsychiatric symptoms of these common disorders. The depression in PD (A. Leentjens, MD, PhD), psychosis in PD (D. Wint, MD, et al), the role of cholinesterase inhibitors in the treatment of PD (D. Aarsland, MD, et al), rapid eye movement behavior disorder as a manifestation of PD and related disorders (B. Boeve, MD, et al), the neuropsychiatric phenomena associated with pharmacologic and surgical therapy with PD (D. Burn, MD, FRCP, and A. Troster, PhD), the role of functional imaging in PDD and DLB (S. Colloby, BSc, MSc, MPhil, and J. O’Brien, BM BCh, MRCPsych, DM), whether DLB and PD are the same entity (D. Aarsland, MD, et al), and the impact of the emerging molecular biology on a classification of PD and DLB (J. L. Cummings, MD) are presented. These articles provide a comprehensive update of the emerging information regarding the phenomenology, neurobiology, and management of the neuropsychiatric symptoms of PD, PDD, and DLB. This special issue provides neuroscientists with a broad view of the links between these disorders and practitioners with practical guidance in their management.