Worldwide, nearly 35.6 million people live with dementia. This number is expected to double by 2030 (65.7 million) and more than triple by 2050 (115.4 million). Dementia affects people in all countries, with more than half (58%) living in low- and middle-income countries. By 2050, this is likely to rise to more than 70%.

Treating and caring for people with dementia currently costs the world more than $604 billion per year. This includes the cost of providing health and social care as well the reduction or loss of income of people with dementia and their caregivers.

Only eight countries worldwide have national programs in place to address dementia. A new report -- Dementia: a public health priority, published by the World Health Organization (WHO) and Alzheimer's Disease International -- recommends that programmes focus on improving early diagnosis; raising public awareness about the disease and reducing stigma; and providing better care and more support to caregivers.

Lack of diagnosis is a major problem. Even in high-income countries, only one fifth to one half of cases of dementia are routinely recognized. When a diagnosis is made, it often comes at a relatively late stage of the disease.

"We need to increase our capacity to detect dementia early and to provide the necessary health and social care. Much can be done to decrease the burden of dementia," says Dr Oleg Chestnov, Assistant Director-General, Noncommunicable Diseases and Mental Health at WHO. "Health-care workers are often not adequately trained to recognize dementia."

Download the report from the World Health Organization here.