Martin Prince

Global prevalence of dementia: a Delphi consensus study.

BACKGROUND 100 years after the first description, Alzheimers disease is one of the most disabling and burdensome health conditions worldwide. We used the Delphi consensus method to determine dementia prevalence for each world region. METHODS 12 international experts were provided with a systematic review of published studies on dementia and were asked to provide prevalence estimates for every WHO world region, for men and women combined, in 5-year age bands from 60 to 84 years, and for those aged 85 years and older. UN population estimates and projections were used to estimate numbers of people with dementia in 2001, 2020, and 2040. We estimated incidence rates from prevalence, remission, and mortality. FINDINGS Evidence from well-planned, representative epidemiological surveys is scarce in many regions. We estimate that 24.3 million people have dementia today, with 4.6 million new cases of dementia every year (one new case every 7 seconds). The number of people affected will double every 20 years to 81.1 million by 2040. Most people with dementia live in developing countries (60% in 2001, rising to 71% by 2040). Rates of increase are not uniform; numbers in developed countries are forecast to increase by 100% between 2001 and 2040, but by more than 300% in India, China, and their south Asian and western Pacific neighbours. INTERPRETATION We believe that the detailed estimates in this paper constitute the best currently available basis for policymaking, planning, and allocation of health and welfare resources.

No health without mental health

About 14% of the global burden of disease has been attributed to neuropsychiatric disorders, mostly due to the chronically disabling nature of depression and other common mental disorders, alcohol-use and substance-use disorders, and psychoses. Such estimates have drawn attention to the importance of mental disorders for public health. However, because they stress the separate contributions of mental and physical disorders to disability and mortality, they might have entrenched the alienation of mental health from mainstream efforts to improve health and reduce poverty. The burden of mental disorders is likely to have been underestimated because of inadequate appreciation of the connectedness between mental illness and other health conditions. Because these interactions are protean, there can be no health without mental health. Mental disorders increase risk for communicable and non-communicable diseases, and contribute to unintentional and intentional injury. Conversely, many health conditions increase the risk for mental disorder, and comorbidity complicates help-seeking, diagnosis, and treatment, and influences prognosis. Health services are not provided equitably to people with mental disorders, and the quality of care for both mental and physical health conditions for these people could be improved. We need to develop and evaluate psychosocial interventions that can be integrated into management of communicable and non-communicable diseases. Health-care systems should be strengthened to improve delivery of mental health care, by focusing on existing programmes and activities, such as those which address the prevention and treatment of HIV, tuberculosis, and malaria; gender-based violence; antenatal care; integrated management of childhood illnesses and child nutrition; and innovative management of chronic disease. An explicit mental health budget might need to be allocated for such activities. Mental health affects progress towards the achievement of several Millennium Development Goals, such as promotion of gender equality and empowerment of women, reduction of child mortality, improvement of maternal health, and reversal of the spread of HIV/AIDS. Mental health awareness needs to be integrated into all aspects of health and social policy, health-system planning, and delivery of primary and secondary general health care.

The global prevalence of dementia: A systematic review and metaanalysis

The evidence base on the prevalence of dementia is expanding rapidly, particularly in countries with low and middle incomes. A reappraisal of global prevalence and numbers is due, given the significant implications for social and public policy and planning.

Alzheimer's disease and vascular dementia in developing countries: prevalence, management, and risk factors

Despite mortality due to communicable diseases, poverty, and human conflicts, dementia incidence is destined to increase in the developing world in tandem with the ageing population. Current data from developing countries suggest that age-adjusted dementia prevalence estimates in 65 year olds are high (>or=5%) in certain Asian and Latin American countries, but consistently low (1-3%) in India and sub-Saharan Africa; Alzheimers disease accounts for 60% whereas vascular dementia accounts for approximately 30% of the prevalence. Early-onset familial forms of dementia with single-gene defects occur in Latin America, Asia, and Africa. Illiteracy remains a risk factor for dementia. The APOE epsilon4 allele does not influence dementia progression in sub-Saharan Africans. Vascular factors, such as hypertension and type 2 diabetes, are likely to increase the burden of dementia. Use of traditional diets and medicinal plant extracts might aid prevention and treatment. Dementia costs in developing countries are estimated to be US

The worldwide economic impact of dementia 2010

73 billion yearly, but care demands social protection, which seems scarce in these regions.

The burden of disease in older people and implications for health policy and practice

To acquire an understanding of the societal costs of dementia and how they affect families, health and social care services, and governments to improve the lives of people with dementia and their caregivers.

Dementia diagnosis in developing countries: a cross-cultural validation study

23% of the total global burden of disease is attributable to disorders in people aged 60 years and older. Although the proportion of the burden arising from older people (≥60 years) is highest in high-income regions, disability-adjusted life years (DALYs) per head are 40% higher in low-income and middle-income regions, accounted for by the increased burden per head of population arising from cardiovascular diseases, and sensory, respiratory, and infectious disorders. The leading contributors to disease burden in older people are cardiovascular diseases (30·3% of the total burden in people aged 60 years and older), malignant neoplasms (15·1%), chronic respiratory diseases (9·5%), musculoskeletal diseases (7·5%), and neurological and mental disorders (6·6%). A substantial and increased proportion of morbidity and mortality due to chronic disease occurs in older people. Primary prevention in adults aged younger than 60 years will improve health in successive cohorts of older people, but much of the potential to reduce disease burden will come from more effective primary, secondary, and tertiary prevention targeting older people. Obstacles include misplaced global health priorities, ageism, the poor preparedness of health systems to deliver age-appropriate care for chronic diseases, and the complexity of integrating care for complex multimorbidities. Although population ageing is driving the worldwide epidemic of chronic diseases, substantial untapped potential exists to modify the relation between chronological age and health. This objective is especially important for the most age-dependent disorders (ie, dementia, stroke, chronic obstructive pulmonary disease, and vision impairment), for which the burden of disease arises more from disability than from mortality, and for which long-term care costs outweigh health expenditure. The societal cost of these disorders is enormous.

Social support deficits, loneliness and life events as risk factors for depression in old age. The Gospel Oak Project VI.

BACKGROUND Research into dementia is needed in developing countries. Assessment of variations in disease frequency between regions might enhance our understanding of the disease, but methodological difficulties need to be addressed. We aimed to develop and test a culturally and educationally unbiased diagnostic instrument for dementia. METHODS In a multicentre study, the 10/66 Dementia Research Group interviewed 2885 people aged 60 years and older in 25 centres, most in Universities, in India, China and southeast Asia, Latin America and the Caribbean, and Africa. 729 had dementia and three groups were free of dementia: 702 had depression, 694 had high education (as defined by each centre), and 760 had low education (as defined by each centre). Local clinicians diagnosed dementia and depression. An interviewer, masked to dementia diagnosis, administered the geriatric mental state, the community screening instrument for dementia, and the modified Consortium to Establish a Registry of Alzheimers Disease (CERAD) ten-word list-learning task. FINDINGS Each measure independently predicted a diagnosis of dementia. In an analysis of half the sample, an algorithm derived from all three measures gave better results than any individual measure. Applied to the other half of the sample, this algorithm identified 94% of dementia cases with false-positive rates of 15%, 3%, and 6% in the depression, high education, and low education groups, respectively. INTERPRETATION Our algorithm is a sound basis for culturally and educationally sensitive dementia diagnosis in clinical and population-based research, supported by translations of its constituent measures into most languages used in the developing world.

Is the cognitive function of older patients affected by antihypertensive treatment ? Results from 54 months of the Medical Research Council's treatment trial of hypertension in older adults

BACKGROUND A companion paper reported a very strong cross-sectional association between handicap and late-life depression. Adjusting for handicap weakened associations between sociodemographic variables and depression. It was unclear whether handicap was a confounder, or a useful summary variable, mediating the effect of a range of sociodemographic disadvantages. This paper focuses on the cross-sectional relationship between depression and demographic variables, social support, and life events. METHOD A community survey of all residents over the age of 65 years of an electoral district in London, UK. RESULTS There was a moderate association between SHORT-CARE pervasive depression and the number of life events experienced over the previous year. Personal illness, bereavement and theft were the most salient events. There was a stronger, graded, relationship between the number of social support deficits (SSDs) and depression. Number of SSDs also related to age, handicap, loneliness and use of homecare services. Loneliness was itself strongly associated with depression; odds ratio 12.4 (7.6-20.0). CONCLUSIONS Problems of collinearity, and the cross-sectional design of the study limited interpretation of the exact nature of the relationship between social support, loneliness, handicap and depression. However, the clustering of these four factors can be used to define a large part of the elderly population with a poor quality of life. An important avenue for future research will be the development and implementation of population intervention strategies designed to address some or all of these problems among older people in general.

A prospective population-based cohort study of the effects of disablement and social milieu on the onset and maintenance of late-life depression. The Gospel Oak Project VII.

Abstract Objective: To establish whether initiation of treatment with diuretic or β blocker is associated over 54 months with change in cognitive function. Design: A cognitive substudy, nested within a randomised, placebo controlled, single blind trial. Setting: 226 general practices from the Medical Research Councils general practice research framework. Subjects: A subset of 2584 subjects sequentially recruited from among the 4396 participants aged 65-74 in the trial of treatment of hypertension in older adults. The 4396 subjects were randomised to receive diuretic, β blocker, or placebo. Subjects had mean systolic pressures of 160-209 mm Hg and mean diastolic pressures <115 mm Hg during an eight week run in. Outcome measures: The rate of change in paired associate learning test (PALT) and trail making test part A (TMT) scores (administered at entry and at 1, 9, 21, and 54 months) over time. Results: There was no difference in the mean learning test coefficients (rate of change of score over time) between the three treatments: diuretic -0.31 (95% confidence interval -0.23 to -0.39), β blocker -0.33 (-0.25 to -0.41), placebo -0.30, (-0.24 to -0.36). There was also no difference in the mean trail making coefficients (rate of change in time taken to complete over time) between the three groups: diuretic -2.73 (95% confidence interval -3.57 to -1.88), β blocker -2.08 (-3.29 to -0.87), placebo -3.01, (-3.69 to -2.32). A less conservative protocol analysis confirmed this negative finding. Conclusion: Treating moderate hypertension in older people is unlikely to influence, for better or for worse, subsequent cognitive function. Key messages Key messages Studies have shown that treating hypertension in older adults reduces cardiovascular mortality and morbidity Treating moderate hypertension with either diuretic or β blocker does not seem to influence cognitive function Concerns about damaging cognition should not deter doctors from treating hypertension in older patients Age should no longer be a factor in the decision to initiate antihypertensive treatment