Newsletter #1 of 4
Dementia is common in older adults in the United States (US); approximately 7.9 million people are living with dementia, of whom 3.95 million carry a diagnosis of at least one dementia type.1-3 However, data from 2 large databases indicate that more than half of individuals with dementia had mixed neuropathologies.4
The most common type of dementia is Alzheimer’s disease (AD) dementia. It accounts for approximately 69.6% of dementia and about 5.5 million people in the US.1-3,5 Vascular dementia is the next most common, accounting for about 20% of dementia and about 1.6 million US individuals.1,2 Other types of dementia are estimated to have the following prevalence in the US: dementia with Lewy bodies (DLB), approximately 5.4% of dementia (~430,000 people);1,6-8 Parkinson’s disease (PD) dementia, approximately 4% of dementia (~320,000 people);7,8 and frontotemporal dementia, approximately 1% of dementia (~80,000 people).1
According to the 2015 National Health and Aging Trends Study, the prevalence of dementia increases with age, although some individuals experience symptom onset at a younger age.9 Moreover, as the US population ages, the number of people with dementia is expected to grow.9
Dementia involves more than cognition
Neuropsychiatric symptoms are common among people with dementia, and their onset can occur at various times in the course of the illness.10-12 Among 209 people with dementia living in long-term care facilities (mean age, 83 years), 79% have one or more clinically significant neuropsychiatric symptom, and 97% of community-dwelling adults aged ≥65 years with dementia (N=408) have one or more neuropsychiatric symptom.10-11
Neuropsychiatric symptoms are a common feature across the dementias and include hallucinations, delusions, agitation/aggression, depression, apathy, elation, anxiety, disinhibition, irritability, and aberrant motor behavior.10
Psychiatric symptoms can occur months, and even years, before the diagnosis of dementia. A study examining 100 individuals with AD specifically found social withdrawal occurred an average of 33 months before diagnosis and was the earliest recognizable psychiatric symptom observed (Figure 1).12
|Figure 1. Psychiatric symptoms in dementia are common and can span the course of the illness.|
In a study of 100 patients with AD dementia, social withdrawal, suicidal ideation, depression, paranoia, anxiety, diurnal rhythm disturbances, and mood changes occurred early in the course of the disease (before diagnosis). Whereas irritability, hallucinations and delusions, agitation and aggression, wandering, and sexually inappropriate behavior were documented within 2 years, on average, after the diagnosis.12
Graph reprinted from Jost BC, et al. J Am Geriatr Soc. 1996;44(9):1078-1081. ©1996 with permission from John Wiley and Sons.
Prevalence of Hallucinations and Delusions
A hallucination is defined as a perception-like experience that occurs without an external stimulus and is sensory in nature.13 A delusion, in contrast, is defined as a false, fixed belief despite evidence to the contrary.13
Although the specific nature of hallucinations and delusions may vary between individual patients and across dementia types, a study of 124 people aged ≥65 years diagnosed with mild or moderate dementia of any type showed that some of the most common delusions were delusions of reference, theft or possessions being hidden, and strangers in the house, also known as phantom boarder delusion (frequency: >20% to 25%).14 Hallucinations documented in this population were second-person auditory hallucinations, visual hallucinations of animals or insects, and visual hallucinations of relatives in the house (frequency: >5% to 20%).14
Approximately 2.4 million people in the US have dementia-related psychosis (ie, experience hallucinations and delusions), with varying prevalence rates across the dementias (Table 1).14-28
|Table 1. Hallucinations and delusions are prevalent across the dementias.|
|No. of People in US with Dementia||Overall Psychosis Prevalence||Hallucinations Prevalence||Delusions Prevalence|
|Alzheimer’s Disease Dementia15-22||~5.5 million||30%||11%-17%||10%-39%|
|Vascular Dementia15,18,20,22||~1.6 million||15%||5%-14%||14%-27%|
|Dementia with Lewy Bodies14,18,23–25||~430,000||75%||55%-78%||40%-57%|
|Parkinson’s Disease Dementia18,21,24,26||~320,000||50%||32%-63%||28%-50%|
|~2.4 million people in the US have dementia‑related psychosis|
Hallucinations and delusions in people with dementia are frequent and persistent, and they may recur over time.
Research on 124 community-dwelling older adults found that of those with dementia, most experienced symptoms of psychosis 2 to 6 times per week.14 A systematic review that included 13 studies reporting at least 2 behavioral and psychotic symptoms of dementia found that although the persistence of psychotic symptoms beyond 3 months was mostly below 30%, hallucinations persisted beyond 3 months in 0% to 52% of patients, and delusions persisted for that period in 0% to 82% of patients.29
Hallucinations and delusions may recur and increase over time in some individuals with dementia.11,30 In a study of 181 people with AD, symptoms of hallucinations and delusions were recurrent, meaning that they tended to come and go over time, such that cross-sectional observation of the frequency of symptoms (12% to 25%) at any visit tended to underestimate the 1-year prevalence rate in this population (36%).30 In a study of 408 community-dwelling adults aged ≥65 years, the proportion with newly identified dementia who experienced hallucinations and delusions approximately doubled over a 5-year period.11 The point prevalence of hallucinations increased from 10% at baseline to 19% to 24% at all subsequent visits, with an overall 5-year period prevalence of approximately 40%.11 The point prevalence of delusions increased from 18% at baseline to 34% to 38% during the last 3 follow-up visits. Approximately 60% of patients experienced delusions at some point during the 5-year period.11
Hallucinations and delusions in dementia may be associated with aggression
In people with dementia, the association between symptoms of hallucinations and delusions and episodes of aggression is complex. Some studies have found that delusions and—to a lesser degree—hallucinations may be associated with aggression in dementia.22,31,32
A study of 270 outpatients with probable AD (of whom, 227 had hallucinations and delusions) who were followed for 12 months reported that the presence of delusions increased the relative risk of physical aggression 2.8-fold after controlling for dementia severity and previous episodes of aggression (relative risk [RR], 2.8; 95% confidence interval [CI], 1.3-4.3; P=0.009).31 However, hallucinations did not increase the relative risk of physical aggression in this study (RR, 1.2; 95% CI, 0.3-2.7; P=0.653).31
In a cross-sectional study of 103,344 nursing home residents aged ≥60 years with dementia, 7120 (6.9%) were reported to have been aggressive in the week prior to their annual health assessment; of those, 1002 people had hallucinations and delusions. Hallucinations were associated with a 1.4-fold increased odds of physical aggression (odds ratio [OR], 1.4; 99% CI, 1.1-1.8), and delusions were associated with a 2-fold increased odds of physical aggression (OR, 2.0; 99% CI, 1.7-2.4) after adjusting for potential confounders (eg, age, gender, severity of cognitive impairment).32 Depression had the highest odds of physical aggression in this study (OR, 3.3; 99% CI, 3.0-3.6).32
In another cross-sectional study of 1155 people diagnosed with probable AD (of whom, 468 had hallucinations or delusions), psychosis increased the odds of physical or verbal aggression in people with moderate (OR, 2.35; 95% CI, 1.78-3.06) or severe (OR, 11.1; 95% CI, 8.4-14.4) stages of AD.22
Hallucinations and delusions are prevalent across the dementias, and the onset of these and other neuropsychiatric symptoms can occur at various times in the course of the illness. Symptoms of dementia-related psychosis are frequent and persistent, and they may recur over time; the nature and duration of episodes vary between patients and across dementia types. Hallucinations and delusions may be associated with the risk of aggression in some patients with dementia, although more research is needed to better understand the potential relationship.
- Goodman RA, Lochner KA, Thambisetty M, et al. Prevalence of dementia subtypes in United States Medicare fee-for-service beneficiaries, 2011-2013. Alzheimers Dement. 2017;13(1):28-37.
- Plassman BL, Langa KM, Fisher GG, et al. Prevalence of dementia in the United States: the Aging, Demographics, and Memory study. Neuroepidemiology. 2007;29(1-2):125-132.
- Hebert LE, Weuve J, Scherr PA, et al. Alzheimer disease in the United States (2010-2050) estimated using the 2010 census. Neurology. 2013;80(19):1778-1783.
- Brenowitz WD, Keene CD, Hawes SE, et al. Alzheimer’s disease neuropathologic change, Lewy body disease, and vascular brain injury in clinic- and community-based samples. Neurobiol Aging. 2017;53:83-92.
- Alzheimer’s Association. 2017 Alzheimer’s disease facts and figures. Alzheimers Dement. 2017;13(4):325-373.
- Vann Jones SA, O’Brien JT. The prevalence and incidence of dementia with Lewy bodies: a systematic review of population and clinical studies. Psychol Med. 2014;44(4):673-683.
- Hogan DB, Fiest KM, Roberts JI, et al. The prevalence and incidence of dementia with Lewy Bodies: a systematic review. Can J Neurol Sci. 2016;43(suppl 1):S83-S95.
- Aarsland D, Zaccai J, Brayne C. A systematic review of prevalence studies of dementia in Parkinson’s disease. Mov Disord. 2005;20(10):1255-1263.
- Chi W, Graf E, Hughes L, et al. Community-Dwelling Older Adults With Dementia and Their Caregivers: Key Indicators From the National Health and Aging Trends Study. Washington, DC: The Office of the Assistant Secretary for Planning and Evaluation; January 2019.
- Margallo-Lana M, Swann A, O’Brien J, et al. Prevalence and pharmacological management of behavioral and psychological symptoms amongst dementia sufferers living in care environments. Int J Geriatr Psychiatry. 2001;16(1):39-44.
- Steinberg M, Shao H, Zandi P, et al. Point and 5-year period prevalence of neuropsychiatric symptoms in dementia: the Cache County Study. Int J Geriatr Psychiatry. 2008;23(2):170-177.
- Jost BC, Grossberg GT. The evolution of psychiatric symptoms in Alzheimer’s disease: a natural history study. J Am Geriatr Soc. 1996;44(9):1078-1081.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Washington, DC: American Psychiatric Publishing; 2013.
- Ballard C, Saad K, Patel A, et al. The prevalence and phenomenology of psychotic symptoms in dementia sufferers. Int J Geriatr Psychiatry. 1995;10(6):477-485.
- Ballard C, Neill D, O’Brien J, et al. Anxiety, depression and psychosis in vascular dementia: prevalence and associations. J Affect Disord. 2000;59(2):97-106.
- Burns A, Jacoby R, Levy R. Psychiatric phenomena in Alzheimer’s disease. I: Disorders of thought content. Br J Psychiatry. 1990;157:72-76, 92-94.
- Burns A, Jacoby R, Levy R. Psychiatric phenomena in Alzheimer’s disease. II: Disorders of perception. Br J Psychiatry. 1990;157:76-81, 92-94.
- Johnson DK, Watts AS, Chapin BA, et al. Neuropsychiatric profiles in dementia. Alzheimer Dis Assoc Disord. 2011;25(4):326-332.
- Lyketsos CG, Lopez O, Jones B, et al. Prevalence of neuropsychiatric symptoms in dementia and mild cognitive impairment: results from the cardiovascular health study. JAMA. 2002;288(12):1475-1483.
- Lyketsos CG, Steinberg M, Tschanz JT, et al. Mental and behavioral disturbances in dementia: findings from the Cache County Study on Memory in Aging. Am J Psychiatry. 2000;157(5):708-714.
- Leroi I, Voulgari A, Breitner JC, et al. The epidemiology of psychosis in dementia. Am J Geriatr Psychiatry. 2003;11(1):83-91.
- Lopez O, Becker JT, Sweet RA, et al. Psychiatric symptoms vary with the severity of dementia in probable Alzheimer’s disease. J Neuropsychiatry Clin Neurosci. 2003;153:346-353.
- Nagahama Y, Okina T, Suzuki N, et al. Classification of psychotic symptoms in dementia with Lewy bodies. Am J Geriatr Psychiatry. 2007;15(11):961-967.
- Aarsland D, Ballard C, Larsen JP, et al. A comparative study of psychiatric symptoms in dementia with Lewy bodies and Parkinson’s disease with and without dementia. Int J Geriatr Psychiatry. 2001;16(5):528-536.
- Ballard C, Holmes C, McKeith I, et al. Psychiatric morbidity in dementia with Lewy bodies: a prospective clinical and neuropathological comparative study with Alzheimer’s disease. Am J Psychiatry. 1999;156(7):1039-1045.
- Lee WJ, Tsai CF, Gauthier S, et al. The association between cognitive impairment and neuropsychiatric symptoms in patients with Parkinson’s disease dementia. Int Psychogeriatr. 2012;24(12):1980-1987.
- Mendez MF, Shapira JS, Woods RJ, et al. Psychotic symptoms in frontotemporal dementia: prevalence and review. Dement Geriatr Cogn Disord. 2008;25(3):206-211.
- Mourik JC, Rosso SM, Niermeijer MF, et al. Frontotemporal dementia: behavioral symptoms and caregiver distress. Dement Geriatr Cogn Disord. 2004;18(3-4):299-306.
- van der Linde RM, Dening T, Stephan BC, et al. Longitudinal course of behavioural and psychological symptoms of dementia: systematic review. Br J Psychiatry. 2016;209(5):366-377.
- Levy ML, Cummings JL, Fairbanks LA, et al. Longitudinal assessment of symptoms of depression, agitation, and psychosis in 181 patients with Alzheimer’s disease. Am J Psychiatry. 1996;153(11):1438-1443.
- Gilley DW, Wilson RS, Beckett LA, et al. Psychotic symptoms and physically aggressive behavior in Alzheimer’s disease. J Am Geriatr Soc. 1997;45(9):1074-1079.
- Leonard R, Tinetti ME, Allore HG, et al. Potentially modifiable resident characteristics that are associated with physical or verbal aggression among nursing home residents with dementia. Arch Intern Med. 2006;166(12):1295-1300.