Only one in five dementia patients in China are correctly diagnosed, according to the China Association for Alzheimer's disease.

"China is heavily affected by Alzheimer's disease, as the population is aging," said Wang Luning, chairwoman of the association. "Many people, including some doctors, have a false perception about the disease, and this is a major reason why diagnosis and treatment rates of Alzheimer's disease is very low."

Zhang Zhenxin, a professor specializing in dementia at Peking Union Medical College Hospital, said many people in China have misconceptions about dementia and believe it is a natural result of aging.

Many patients are sent by their family members to hospital for diagnosis only after the disease has become serious, she said, adding that incorrect diagnoses by doctors often delay effective treatment.

"The incidence of dementia is closely related with age," said Zhang Shouzi, a psychiatric doctor at Beijing Geriatric Hospital. "In most people who develop dementia in China, the symptoms begin to show after age 60, and up to 40 percent of people who reach 85 years old are at risk of developing dementia."

Currently, there is no cure for dementia and almost all patients with the condition eventually lose the ability to care for themselves. However, early diagnosis and proper medication can keep the disease under control and delay its effects, Zhang Shouzi said.