Elsevier

The Lancet

Volume 390, Issue 10113, 16–22 December 2017, Pages 2673-2734
The Lancet

The Lancet Commissions
Dementia prevention, intervention, and care

https://doi.org/10.1016/S0140-6736(17)31363-6Get rights and content

Section snippets

Executive summary

Acting now on dementia prevention, intervention, and care will vastly improve living and dying for individuals with dementia and their families, and in doing so, will transform the future for society.

Dementia is the greatest global challenge for health and social care in the 21st century. It occurs mainly in people older than 65 years, so increases in numbers and costs are driven, worldwide, by increased longevity resulting from the welcome reduction in people dying prematurely. The Lancet

Demographics and dementia

The number of people with dementia is rising rapidly (figure 1), primarily due to worldwide ageing populations, particularly in LMICs.1, 17 This association is expected and widely reported.18, 19

Although no disease-modifying treatment for any common dementia is available, a delay in the onset of dementia would benefit even the oldest adults.20 An unexpected decline in age-specific dementia incidence or prevalence has been reported in some countries, such as the USA, the UK, Sweden, the

Modifiable risk factors for dementia

Prevention is better than cure and underlies the growing interest in modifiable risk factors. Any future disease-modifying treatment for dementia will not remove the need for its effective prevention. In published work on dementia risk, midlife has been defined as 45–65 years and later life as older than 65 years. We have used these definitions throughout this Commission for consistency, but these risks are often relevant throughout the life course. Much of this work focuses on estimating the

Interventions to prevent dementia

The existence of potentially modifiable risk factors does not mean that all dementia is preventable or make it more treatable once established. Some intervention studies142, 143 have built on the evidence of modifiable dementia risk factors to reduce dementia incidence, testing the effects of physical activity, cognitive training, or medication, including antihypertensives. The low dementia incidence means that trial sample sizes have to be large and length of study long to show a reduction in

FINGER study

The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER)160, 174 provided four intensive lifestyle-based strategies (diet, exercise, cognitive training, and vascular management) to more than 600 people who were older than 60 years and at high risk of dementia according to their age, sex, education, systolic blood pressure, total cholesterol, and physical activity.175 The study compared cognition in the intervention group versus controls who received

Early detection of preclinical Alzheimer's disease

Preclinical Alzheimer's disease occurs when there are early Alzheimer's pathogenic changes but no memory impairment.181 These pathogenic changes in Alzheimer's disease include extracellular deposition of amyloid β (Aβ protein) from cleaved amyloid precursor protein, which is the main component of plaques, and intracellular accumulation of tau protein, which is the main constituent of tangles.

The main purpose of preclinical detection of Alzheimer's disease is to identify individuals at high risk

Mild cognitive impairment

Mild cognitive impairment is also occasionally called cognitive impairment no dementia.197, 198 It has been defined as an objective cognitive impairment, reported by a patient or relative, in a person with essentially normal functional activities, who does not have dementia.199 It can broadly be considered as an intermediate state between healthy ageing and early dementia, which sometimes reverts to healthy cognition. Mild cognitive impairment is probably best conceptualised as a probability

Increasing the diagnosis

Public health strategies and plans to increase the diagnosis of dementia are in place in many countries, including Bulgaria, Denmark, France, Israel, Malta, the Netherlands, Norway, Switzerland, and the UK. The English strategy was instituted after variations in diagnosis across regions of England were highlighted.228 The strategy consists of three parts. First, a public and practitioner information campaign, including television and newspaper adverts to counter the argument that a diagnosis of

Making the diagnosis

National guidelines in many countries recommend that people with suspected dementia are referred to a specialist memory clinic or individual specialist doctor.234, 252 Guidelines recommend a systematic approach, including history taking from the patient and informant, review of medication, structured cognitive assessment, blood tests, and (in some countries) structural imaging. The blood tests are to detect comorbid illness, whose treatment might improve cognition, and the very rare reversible

Principles of assessment and treatment in people with dementia

People with dementia have complex problems because they have symptoms in many domains. These include cognition, neuropsychiatric symptoms, activities of daily living, and usually comorbid physical illnesses. Interventions have to consider the person as a whole and attend to their medical, cognitive, emotional, psychological, and social needs. Thus, individuals require different treatments and these will change with the course of the dementia. Assessment of an individual's problems in these

Drugs for cognition

The only approved drug treatments in many countries for cognitive symptoms of dementia are for Alzheimer's disease, dementia with Lewy bodies, or Parkinson's disease dementia. They target biochemical abnormalities as a consequence of neuronal loss, but do not modify the underlying neuropathology or its progression. Cholinesterase inhibitors might partly restore the deficit in acetylcholine arising from loss of neurons in the nucleus basalis of Meynert and in the central septal area, projecting

Other cognitive interventions

Cognitive interventions encompass a range of approaches to maintain or improve cognition through mentally stimulating activities. There are three main cognitive intervention approaches.

Exercise interventions for cognition

The evidence from RCTs that exercise interventions improve cognitive and functional outcomes in patients with dementia is highly variable. A systematic review375 of four RCTs of exercise interventions in Alzheimer's disease reported a significant overall SMD on cognitive outcomes compared with controls of 0·75 (95% CI 0·32–1·17). By contrast, a Cochrane review376 of nine studies with 409 participants did not find a significant difference and rated the quality of evidence as very low. The

Neuropsychiatric symptoms

Neuropsychiatric symptoms in dementia are common, they generally increase with the severity of dementia and affect nearly everyone with dementia at some point during their illness.383, 384 Although many different symptoms exist, they often co-occur and there are several different models of how they cluster—eg, into affective, psychotic, and other symptoms.385 They also vary with the underlying cause of dementia, with visual hallucinations being more common in Lewy body dementia.386 Of those

Agitation

Many people with dementia show a range of behaviours, including restlessness, pacing, repetitive vocalisations, and verbally or physically aggressive behaviour that is usually described as agitation.421, 422 The behaviours are often accompanied by a feeling of inner tension, although this tension is more difficult to detect in people with more severe dementia. The cause of these symptoms varies. They might be a communication of physical or psychological distress, a misinterpretation of threat,

Depression

Depression is common in people with dementia. Estimates of its prevalence vary, but probably more than 20% of people with dementia have diagnosable depression at any one time, and many others have some depressive symptoms.468 It is distressing, reduces quality of life, exacerbates cognitive and functional impairment, and is associated with increased mortality and carer stress and depression.469, 470 Many people with mild depression improve without specific treatment, although the services they

Sleep

Causes of sleep disturbances in older people with dementia are heterogeneous and complex, occurring in 25–55% of individuals with neurodegenerative dementias.491, 492, 493 Sleep disturbances might be caused by one or more of pain and physical health conditions, anxiety, lack of activity, and neurodegenerative changes. Impaired melatonin production occurs in Alzheimer's disease and other dementias because of neuronal loss in the suprachiasmatic nucleus,494, 495 leading to a decreased regularity

Apathy

Apathy is one the commonest and most persistent neuropsychiatric symptoms.387 In a review511 of the largest non-pharmacological intervention studies, 15 of 17 studies of tailored activity and eight of the nine studies using non-tailored activity reported a positive or partly positive outcome. However, the commonly used scales have items related to time spent doing activity so the evaluation might be somewhat circular: provide tailored activity and people spend time doing things that interest

Family carers as decision makers

Family carers are the most important resource available for people with dementia.234 Caring can bring emotional rewards but also difficulties for a family member. When dementia is mild, decisions about everyday life, social care, and medical treatment can usually be made by the person with dementia, usually with support from family or friends. As dementia progresses, the person with dementia loses the mental capacity to make more complex decisions and the carer becomes the substitute decision

Definitions of abuse

Abuse is defined as “a violation of an individual's human and civil rights by another person(s)”546 and can take different forms. These include verbal or psychological abuse, encompassing screaming and shouting, name-calling, threatening, or humiliating and physical abuse, including hitting, shoving, or handling roughly, inappropriate medication use, restraint, or confinement. Proportionate self-defence is not abuse. Neglect (including allowing self-neglect) is defined as ignoring medical or

Dying with dementia

Dementia shortens life, even after controlling for age and multi-morbidity. This outcome varies between populations and progression might be faster in women and individuals with younger-onset dementia.561 A UK population study562 found a median survival time from diagnosis of dementia to death of 4·1 years. In a primary-care study,246 where diagnosis sometimes occurs at a late stage, median survival times from diagnosis were 6·7 years in individuals diagnosed at ages 60–69 years, decreasing to

Case management models for people with dementia

Case management is delivered by a specific individual or a team through an individualised, collaborative, evidence-based plan of care with and for patients and family needs. It integrates the complex network of health and social care professionals needed in dementia and responds to patient needs.211 Case management usually includes standardised assessment, carer education, and implementation of an individualised plan. Social workers, nurses, or specialist dementia workers can be coordinators to

Conclusions

Continued progress will build on what has long informed dementia care: to prevent the preventable, treat the treatable, and care for both the person living with dementia and the carer. In this Commission, we have brought these strands together, informed by our understanding of the best evidence, and explained the reasons for our conclusions. Evidence is always incomplete but we present the available evidence and the conclusions we have reached transparently. From this evidence and by

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References (629)

  • Y Stern

    Cognitive reserve in ageing and Alzheimer's disease

    Lancet Neurol

    (2012)
  • DE Barnes et al.

    The projected effect of risk factor reduction on Alzheimer's disease prevalence

    Lancet Neurol

    (2011)
  • JS Kuiper et al.

    Social relationships and risk of dementia: a systematic review and meta-analysis of longitudinal cohort studies

    Ageing Res Rev

    (2015)
  • I Casserly et al.

    Convergence of atherosclerosis and Alzheimer's disease: inflammation, cholesterol, and misfolded proteins

    Lancet

    (2004)
  • GJ Biessels et al.

    Risk of dementia in diabetes mellitus: a systematic review

    Lancet Neurol

    (2006)
  • CQ Huang et al.

    Chronic diseases and risk for depression in old age: a meta-analysis of published literature

    Ageing Res Rev

    (2010)
  • The global impact of dementia 2013–2050: policy brief for heads of Government

    (2013)
  • M Prince et al.

    World Alzheimer report 2015—the global impact of dementia: an analysis of prevalence, incidence, cost and trends

    (2015)
  • L Jones et al.

    Development of a model for integrated care at the end of life in advanced dementia: a whole systems UK-wide approach

    Palliat Med

    (2016)
  • FE Matthews et al.

    A two decade dementia incidence comparison from the Cognitive Function and Ageing Studies I and II

    Nat Commun

    (2016)
  • International statistical classification of diseases and related health problems, 10th revision

    (2016)
  • T Stevens et al.

    Islington study of dementia subtypes in the community

    Br J Psychiatry

    (2002)
  • N Mukadam et al.

    Reducing the stigma associated with dementia: approaches and goals

    Aging Health

    (2012)
  • D Blazer

    Neurocognitive disorders in DSM-5

    Am J Psychiatry

    (2013)
  • PS Sachdev et al.

    Classifying neurocognitive disorders: the DSM-5 approach

    Nat Rev Neurol

    (2014)
  • M Carone et al.

    Estimating the lifetime risk of dementia in the Canadian elderly population using cross-sectional cohort survival data

    J Am Stat Assoc

    (2014)
  • X Song et al.

    Age-related deficit accumulation and the risk of late-life dementia

    Alzheimers Res Ther

    (2014)
  • B Intzandt et al.

    Is cardiac rehabilitation exercise feasible for people with mild cognitive impairment?

    Can Geriatr J

    (2015)
  • C Cooper et al.

    Systematic review and meta-analysis to estimate potential recruitment to dementia intervention studies

    Int J Geriatr Psychiatry

    (2014)
  • M Prince et al.

    The global prevalence of dementia: a systematic review and metaanalysis

    Alzheimers Dement

    (2013)
  • C Brayne et al.

    Dementia before death in ageing societies—the promise of prevention and the reality

    PLoS Med

    (2006)
  • SE Tom et al.

    Characterization of dementia and Alzheimer's disease in an older population: updated incidence and life expectancy with and without dementia

    Am J Public Health

    (2015)
  • KC Manton et al.

    Declining prevalence of dementia in the U.S. elderly population

    Adv Gerontol

    (2005)
  • EM Schrijvers et al.

    Is dementia incidence declining?: Trends in dementia incidence since 1990 in the Rotterdam Study

    Neurology

    (2012)
  • C Qiu et al.

    Twenty-year changes in dementia occurrence suggest decreasing incidence in central Stockholm, Sweden

    Neurology

    (2013)
  • CL Satizabal et al.

    Incidence of dementia over three decades in the Framingham Heart Study

    N Engl J Med

    (2016)
  • KM Langa et al.

    A comparison of the prevalence of dementia in the United States in 2000 and 2012

    JAMA Intern Med

    (2017)
  • HH Dodge et al.

    Trends in the prevalence of dementia in Japan

    Int J Alzheimers Dis

    (2012)
  • H Okamura et al.

    prevalence of dementia in Japan: a systematic review

    Dement Geriatr Cogn Disord

    (2013)
  • YT Wu et al.

    The changing prevalence and incidence of dementia over time—current evidence

    Nat Rev Neurol

    (2017)
  • M Loef et al.

    Midlife obesity and dementia: meta-analysis and adjusted forecast of dementia prevalence in the United States and China

    Obesity (Silver Spring)

    (2013)
  • A Lim et al.

    Clinico-neuropathological correlation of Alzheimer's disease in a community-based case series

    J Am Geriatr Soc

    (1999)
  • EB Larson

    Illnesses causing dementia in the very elderly

    N Engl J Med

    (1993)
  • DA Snowdon et al.

    Brain infarction and the clinical expression of Alzheimer disease. The Nun Study

    JAMA

    (1997)
  • KM Langa et al.

    Mixed dementia: emerging concepts and therapeutic implications

    JAMA

    (2004)
  • JA Sonnen et al.

    Pathologic correlates of dementia in individuals with Lewy body disease

    Brain Pathol

    (2010)
  • B Cholerton et al.

    Neuropathologic correlates of cognition in a population-based sample

    J Alzheimers Dis

    (2013)
  • KS SantaCruz et al.

    Alzheimer disease pathology in subjects without dementia in 2 studies of aging: the Nun Study and the Adult Changes in Thought Study

    J Neuropathol Exp Neurol

    (2011)
  • L White et al.

    Cerebrovascular pathology and dementia in autopsied Honolulu-Asia Aging Study participants

    Ann N Y Acad Sci

    (2002)
  • EB Larson et al.

    New insights into the dementia epidemic

    N Engl J Med

    (2013)
  • Cited by (3974)

    View all citing articles on Scopus
    View full text