Time to confront the global dementia crisis
The Lancet Neurology
High-income countries are not the only ones facing a dementia crisis as their populations age. According to the Alzheimer’s Disease International (ADI) Delphi consensus study, by 2040, 71% of all people with dementia will be living in developing countries. In addition to the personal devastation for these 58 million people and their families, the economic burden is likely to be immense: in this issue of The Lancet Neurology, Kalaria and colleagues estimate that the total costs of ageing-related dementia in developing countries were already more than US$70 billion per year in 2005, when prevalence was only 15 million. Despite the scale of the problem, there is relatively little research into dementia in developing nations—just 10% has focussed on countries where more than 66% of people with these disorders live. The 10/66 Dementia Research Group, which celebrates its tenth anniversary at the end of August, is working with ADI to address this imbalance, but dementia in the developing world remains dangerously neglected within communities, by researchers, and by policy makers.
Greater awareness, policy change, and development of health-care services all stem from good research. Over the past decade, through collaborations between researchers in developed and developing countries, the 10/66 group has begun to quantify the occurrence of dementia in low-income and middle-income countries. This major undertaking has included development of more sensitive methods to diagnose dementia, because previous standard assessments are inappropriate in many settings—no-one will do well on a clock-drawing test if they are not familiar with clocks or drawing. 10/66 has also assessed availability of care, and the effects of care-giving on families. Their research, and the work of ADI and its 77 national member associations, is already starting to increase awareness at the community and primary-care levels. For example, after a successful randomised trial in India, the 10/66 research group’s “helping carers to care” initiative is now being rolled out in other countries.
These achievements should not detract from the challenges that remain. Dementia is under-diagnosed in many societies owing to stigma or misclassification as normal ageing. Reliable prevalence data are available for only two countries in Africa, and even less is known about the prevalence of different dementia types. How prevalence, incidence, and survival are affected by ethnic subgroup or economic status remain largely unknown. Better understanding of dementia in developing countries is likely to provide valuable new information on risk factors, genetics, and potential new treatments. Lower age-adjusted rates of Alzheimer’s disease in Nigeria and India than in high-income countries could reflect differences in lifestyle or genetics—for example, APOE ɛ4 is not a risk factor for Alzheimer’s disease in several sub-Saharan African populations. Traditional medicines such as some Chinese herbs are also a promising source of potential new treatments. Collaborations between researchers in developing and developed countries will benefit all parties.
But research and grass-roots implementation of care strategies can take us only so far. Unfortunately, the problem of dementia in developing countries is still largely neglected by governments and international funding agencies. While high-profile initiatives such as the Global Fund to Fight AIDS, Tuberculosis, and Malaria have increased awareness about infectious diseases, other diseases have been left behind. When non-communicable diseases have made their way on to the global health policy agenda, the focus has been on cardiovascular disease, diabetes, and cancer, with no mention of dementia. Estimates suggest that similar numbers of people had dementia worldwide in 2007 as had HIV/AIDS—about 33 million in each case. The proportions of these people who were living in developing countries were given at about 95% for HIV/AIDS and 60—70% for dementia. Figures for aid awarded to dementia initiatives in developing countries are scarce, but they are likely to be a tiny fraction of the 25% of international health-care aid currently ear-marked for HIV/AIDS. This difference is in large part attributable to advocacy: unfortunately, patients with dementia in developing countries are rarely in a position to campaign about their disorder.
In addition to their ongoing research, over the next 2 years the 10/66 Dementia Research Group aims to increase awareness of dementia in developing countries at the regional, national, and international levels. Their plans include regular policy briefings based on results from their population surveys, and annual forums for policy makers. When these initiatives begin, governments and international funding agencies must listen. Further neglect of this issue is unacceptable in the face of a global dementia epidemic with which even high-income countries are expected to struggle.