Dementia in developing countries
9 February 2009
The reported prevalence of dementia in developing countries is surprisingly low. Now, an international collaboration led by Martin Prince at the Institute of Psychiatry has found that its prevalence has been substantially underestimated in low- and middle-income countries, and that it is almost as common as in developed countries. Moreover, dementia is imposing a considerable psychological and economic burden on large numbers of carers.
Professor Prince leads the 10/66 Dementia Research Group, an international collaboration assessing the impact of dementia and related conditions in low- and middle-income countries. It derives its name from the fact that less than one-tenth of population-based dementia research has focused on the two-thirds or more of all people with dementia who live in developing countries.
Members of the collaboration assessed almost 15 000 people over the age of 65 in 11 countries, using culturally sensitive tools to factor out different perceptions of ageing and dementia.
The results suggested that there is a 'hidden epidemic' of dementia, its prevalence in urban settings in Latin America comparable to those seen in Europe and the USA. By 2040, the number of people with dementia in Latin America - more than nine million - is likely to match that in North America.
Moreover, as healthcare is generally limited in such regions, patient care usually falls to spouses or other family members. Dementia is the single biggest factor contributing to dependency, creating significant economic and psychological pressures: carers are often forced to cut working hours and are at high risk of depression or other forms of mental distress.
Previous underestimates may reflect the fact that people in lower-income countries are less likely to seek help for elderly relatives showing signs of dementia - it is often seen as a 'natural' part of ageing.
The findings suggest that there is a major health burden going unaddressed in many countries. More positively, intervention studies in Russia and India carried out by the 10/66 Group (funded by the World Health Organization) suggest that simple home-based interventions can provide significant benefits to both carers and patients.
Image: In Latin American countries such as Cuba, dementia may be more common than thought; E Martino/Panos.
References
Llibre Rodriguez JJ et al. Prevalence of dementia in Latin America, India, and China: a population-based cross-sectional survey. Lancet 2008;372(9637): 464-74.
Llibre Rodríguez J et al. The prevalence, correlates and impact of dementia in Cuba. A 10/66 Group population-based survey. Neuroepidemiology 2008;31(4):243-51.