title: The psychosis spectrum in Parkinson disease.
abstract: In 2007, the clinical and research profile of illusions, hallucinations, delusions and related symptoms in Parkinson disease (PD) was raised with the publication of a consensus definition of PD psychosis. Symptoms that were previously deemed benign and clinically insignificant were incorporated into a continuum of severity, leading to the rapid expansion of literature focusing on clinical aspects, mechanisms and treatment. Here, we review this literature and the evolving view of PD psychosis. Key topics include the prospective risk of dementia in individuals with PD psychosis, and the causal and modifying effects of PD medication. We discuss recent developments, including recognition of an increase in the prevalence of psychosis with disease duration, addition of new visual symptoms to the psychosis continuum, and identification of frontal executive, visual perceptual and memory dysfunction at different disease stages. In addition, we highlight novel risk factors - for example, autonomic dysfunction - that have emerged from prospective studies, structural MRI evidence of frontal, parietal, occipital and hippocampal involvement, and approval of pimavanserin for the treatment of PD psychosis. The accumulating evidence raises novel questions and directions for future research to explore the clinical management and biomarker potential of PD psychosis.
authors.affiliation: KCL-PARCOG group, Institute of Psychiatry, Psychology &Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.|Department of Old Age Psychiatry, Institute of Psychiatry, Psychology &Neuroscience, King's College London, UK. De Crespigny Park, London SE5 8AF, UK.
authors.forename: Dominic H
authors.initials: DH
authors.lastname: Ffytche
authors.affiliation: KCL-PARCOG group, Institute of Psychiatry, Psychology &Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.|University of Exeter Medical School, University of Exeter, EX1 2LU, UK.
authors.forename: Byron
authors.initials: B
authors.lastname: Creese
authors.affiliation: KCL-PARCOG group, Institute of Psychiatry, Psychology &Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.|Neurodegeneration Imaging Group, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology &Neuroscience, King's College London, 125 Coldharbour Lane, London SE5 9NU, UK.
authors.forename: Marios
authors.initials: M
authors.lastname: Politis
authors.affiliation: KCL-PARCOG group, Institute of Psychiatry, Psychology &Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.|Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, National Parkinson Foundation Centre of Excellence, King's College London/Kings College Hospital, 5 Cutcombe Road, London SE5 9RT, UK.
authors.forename: K Ray
authors.initials: KR
authors.lastname: Chaudhuri
authors.affiliation: KCL-PARCOG group, Institute of Psychiatry, Psychology &Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.|Departments of Psychiatry and Neurology, Perelman School of Medicine at the University of Pennsylvania 3615 Chestnut Street, #330, Philadelphia, Pennsylvania 19104, USA.|Parkinson's Disease and Mental Illness Research, Education and Clinical Centres (PADRECC and MIRECC), Philadelphia Veterans Affairs Medical Centre 3900 Woodland Avenue, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Weintraub
authors.affiliation: KCL-PARCOG group, Institute of Psychiatry, Psychology &Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.|University of Exeter Medical School, University of Exeter, EX1 2LU, UK.
authors.forename: Clive
authors.initials: C
authors.lastname: Ballard
authors.affiliation: KCL-PARCOG group, Institute of Psychiatry, Psychology &Neuroscience, King's College London, De Crespigny Park, London SE5 8AF, UK.|Department of Old Age Psychiatry, Institute of Psychiatry, Psychology &Neuroscience, King's College London, UK. De Crespigny Park, London SE5 8AF, UK.
authors.forename: Dag
authors.initials: D
authors.lastname: Aarsland
mesh_terms: D006801:Humans; D010300:Parkinson Disease / Q000523:psychology*; D011618:Psychotic Disorders / Q000209:etiology* / Q000523:psychology*