This figure is significantly higher than the 2003 worldwide estimate of $250 billion by the same researchers, revealing that costs have accelerated in just two years and underscoring the need for more research into the disease.
The $315.4 billion figure is higher than the total budget of all but eight of the world's countries - the United States, Japan, Germany, France, Great Britain, Italy, China and Spain, the researchers said.
Caused by greying populationLead author Dr Anders Wimo of the Karolinska Institutet in Stockholm attributed the rise to the "greying of the world," together with the higher gross domestic product in developing countries that boosts the wages of medical personnel and caregivers. Just over half - 54 percent - of the world's dementia patients live in developing countries and account for 23 percent of the total costs, according to the study.
Dementia refers to cognitive and intellectual deficiencies involving memory, language, motor skills, organising, reasoning and recognition of familiar faces. Alzheimer's disease is the most common cause of dementia. Dementia strikes 1 percent of those between 60 and 64, and becomes more common with the advancement of age, affecting 45 percent in the 95-plus age group.
Wimo calculated the cost of dementia by combining estimates of its prevalence with medical and non-medical charges in each country. The worldwide total also included $105 billion for the cost of "informal care," the lost wages of caregivers - many of whom are retired spouses - responsible for providing "support in personal activities of daily life," such as bathing, dressing and grooming.
The researchers calculated that 90 percent of dementia patients lived at home in developing countries and relied on 1.6 hours of informal care per day, the same amount for those in developed countries, of which 73 percent lived at home.
The study figures came as no surprise to Dr Sam Gandy, chairman of the US Alzheimer's Association's Medical and Scientific Advisory Council.
Research funds decliningGandy decried the decline in research dollars by the US National Institutes of Health, a trend that started in 2003 and has hit Alzheimer's harder than cancers and HIV, he said. "The NIH has had to prioritise its resources, and diseases that affect younger people may be considered a higher priority," he said.
Available drugs for Alzheimer's patients only treat symptoms of the disease. But nine drugs currently being tested in clinical trials show promise in halting the progression of Alzheimer's, he said.
"We hope to have an effective medication within the next five years. We're also hoping to have developed a blood or brain scan to identify people at risk, so we can start treatment before the disease develops," Gandy said.
Cure is top priorityMeanwhile, doctors treating patients with dementia believe the number one funding priority should be finding a cure. Dr Charles DeCarli, director of the Alzheimer's Disease Centre at the University of California, Davis, said that "hot on the heels of finding a cure" is a pressing need to develop a "social infrastructure" that provides more efficient care for patients and relieves some of the burden on family members.
"We're finding patients with dementia overuse the system for all the wrong reasons. Patients come in by ambulance, because they forgot their meds and faint, or they're found confused in the streets, and a concerned neighbour will call the emergency services," he said.
DeCarli advocates more adult day-care centres, where dementia patients can be cared for around the clock. "We're seeing one or two, but what we really need is one in every neighbourhood," he said. – (HealthDayNews)
Read more:Alzheimer’s and dementia Centre
April 2007