Clinical and neurocognitive aspects of hallucinations in Alzheimer’s disease

Abstract

Due to their prevalence, hallucinations are considered as one of the most frequent psychotic symptom in Alzheimer’s disease (AD). These psychotic manifestations reduce patients’ well-being, increase the burden of caregivers, contribute to early institutionalization, and are found to be related with the course of cognitive decline in AD. Considering their consequences, we provide a comprehensive account of the current state of knowledge about the prevalence and characteristics of hallucinations in AD. We provide a comprehensive and testable theoretical model about hallucinations in AD: the ALZHA (ALZheimer and HAllucinations) model. In this model, neurological, genetic, cognitive, affective, and iatrogenic factors associated with hallucinations in AD are highlighted. According to this model, hallucinations in AD first involve trait markers (i.e., cognitive deficits, neurological deficits, genetic predisposition and/or sensory deficits) to which state markers that may specifically trigger these experiences are added (e.g., psychological distress and/or iatrogenic factors). Finally, we provide recommendations for assessment and management of these psychotic manifestations in AD, with the aim to both serve patients, caregivers, and health professionals.

Understanding hallucinations in probable Alzheimer's disease: Very low prevalence rates in a tertiary memory clinic

“…1 , Supplementary Tables 1ab ). Their presence has been repeatedly associated with more severe cognitive and functional decline, earlier institutionalization, higher burden of disease, and increased mortality [4] . It is therefore essential to better understand hallucinations in AD.…”

Identifying Patterns in Signs and Symptoms Preceding the Clinical Diagnosis of Alzheimer’s Disease: Retrospective Medical Record Review Study and a Nested Case-control Design

“…The researcher discovered that individuals with AD have higher odds of auditory disturbances. This finding, to my knowledge, is novel and this is the first study that has reported auditory disturbances as being predictive of AD, excluding auditory hallucinations, which are considered to be frequent psychotic symptoms of AD (25). There could be biological plausibility that could be investigated with a larger sample, as the result is of borderline significance due to small sample size.…”

Evaluation of the efficacy of pimavanserin in the treatment of agitation and aggression in patients with Alzheimer's disease psychosis: A post hoc analysis

“…[1][2][3] More than half of patients with AD will experience psychosis during their illness. [4][5][6] Hallucinations and delusions are frequently distressing to the individual and their caregivers and are associated with worse disease outcomes relative to AD patients without psychosis, 4 including accelerated cognitive decline, 7,8 more rapid progression of functional impairment, 9 increased hospital admissions, 10 earlier admission to institutional care, 8,9 and increased mortality. 9,11 In addition, psychotic symptoms are often antecedent to or comorbid with other neuropsychiatric symptoms like agitation, aggression, and depression, further adding to the impact on the individual and others making Alzheimer's disease psychosis (ADP) more difficult to treat.…”