Revisiting Criteria for Psychosis in Alzheimer’s Disease and Related Dementias: Toward Better Phenotypic Classification and Biomarker Research

Abstract

Background: Psychotic symptoms are common in Alzheimer's disease (AD) and related neurodegenerative disorders and are associated with more rapid disease progression and increased mortality. It is unclear to what degree existing criteria are utilized in clinical research and practice. Objective: To establish research criteria for the diagnosis of psychosis in AD. Methods: The International Society to Advance Alzheimer's Research and Treatment (ISTAART) Neuropsychiatric Symptoms (NPS) Professional Interest Area (PIA) psychosis subgroup reviewed existing criteria for psychosis in AD and related dementias. Through a series of in person and on-line meetings, a priority checklist was devised to capture features necessary for current research and clinical needs. PubMed, Medline and other relevant databases were searched for relevant criteria. Results: Consensus identified three sets of criteria suitable for review including those of Jeste and Finkel, Lyketsos, and the Diagnostic and Statistical Manual for Mental Disorders, 5th edition. It was concluded that existing criteria could be augmented by including a more specific differentiation between delusions and hallucinations, address overlap with related conditions (agitation in particular), adding the possibility of symptoms emerging in the preclinical and prodromal phases, and building on developing research in disease biomarkers. Conclusion: We propose criteria, developed to improve phenotypic classification of psychosis in AD, and advance the research agenda in the field to improve epidemiological, biomarker, and genetics research in the field. These criteria serve as a complement to the International Psychogeriatric Association criteria for psychosis in neurocognitive disorders.

Neuropsychiatric symptoms in cognitively normal older persons, and the association with Alzheimer’s and non-Alzheimer’s dementia

“…Potentially, the future diagnostic criteria of late-life psychotic disorders may also incorporate the newer biomarkers of dementia (such as those related to amyloid protein, tau protein, and neuronal injury) [10] to definitively exclude underlying neurodegenerative processes, especially when these biomarkers become more accessible to general clinicians in the foreseeable future. Such approach is not inconsistent with the direction taken by the recently proposed consensus criteria for psychosis in Alzheimer's disease [64], where there is an increasing emphasis that late-life psychotic disorders may potentially be manifestations of preclinical and prodromal Alzheimer's disease.…”

The Effects of Confinement on Neuropsychiatric Symptoms in Alzheimer’s Disease During the COVID-19 Crisis

“…Another classification for neuropsychiatric symptoms in AD was proposed by Ismail et al [22] who classified these symptoms into five categories: drive and motivation, emotional dysregulation, impulsivity, social inappropriateness, and abnormal perceptions or thoughts. To overcome the classification limitation of neuropsychiatric symptoms in AD, Fischer et al [23] suggested that any classification system should address their overlap with related conditions (especially, regarding agitation), recognize that symptoms may emerge in the preclinical and prodromal phases, and add a more specific differentiation between delusions and hallucinations. Regardless of their classification, neuropsychiatric symptoms in AD have been captured by the Neuropsychiatric Inventory-Questionnaire (NPIQ) [24] for decades.…”

Informant‐based tools for assessment and monitoring of cognition, behavior, and function in neurocognitive disorders: Systematic review and report from a CCCDTD5 Working Group

“…Another challenge has been the under‐recognition of behavioral symptoms of NCDs, partly due to variability in terminology and criteria used to describe these symptoms 81–83 . Recent work has addressed these issues by clarifying the nosological issues and criteria for diagnosis of behavioral syndromes throughout the spectrum of NCDs 82 .…”

“…Another challenge has been the under‐recognition of behavioral symptoms of NCDs, partly due to variability in terminology and criteria used to describe these symptoms 81–83 . Recent work has addressed these issues by clarifying the nosological issues and criteria for diagnosis of behavioral syndromes throughout the spectrum of NCDs 82 . Use of informant‐based tools described in this review may further standardize the assessment and management of behavioral symptoms that is particularly important during the current pandemic and beyond due to unique vulnerabilities of this population 84 …”

“…[81][82][83] Recent work has addressed these issues by clarifying the nosological issues and criteria for diagnosis of behavioral syndromes throughout the spectrum of NCDs. 82 Use of informant-based tools described in this review may further standardize the assessment and management of behavioral symptoms that is particularly important during the current pandemic and beyond due to unique vulnerabilities of this population. 84 This review has several limitations.…”