A quick test that tells if your loved one is at risk of Alzheimer’s disease has been devised by Banner Sun Health Research Institute in Arizona, which specializes in the disease.

The 21-question test distinguishes between normal absent-mindedness and the more sinister memory lapses that may signal the early stages of dementia.

The questions are designed to be answered by a spouse or close friend.

The Alzheimer’s Questionnaire, which is almost 90% accurate, measures mild cognitive impairment (MCI), the slight memory lapses that can be a precursor of the disease.

Up to 15% of people with MCI develop Alzheimer’s within the next year.

The lack of a cure for dementia means that some may not want to take the test.

Some questions, including one about making the same statements over the course of a day, known as repetitiveness, were found to be particularly valuable.

The 21-question test distinguishes between normal absent-mindedness and the more sinister memory lapses that may signal the early stages of dementia

The 21 questions are answered with a simple “yes” or “no”. A “yes” is given a score of one or two and a “no” always scores zero, giving a maximum possible score of 27.

Someone who scores under 5 is advised that there is no cause for concern. A score of 5 to 14 suggests mild cognitive impairment (MCI)– or memory lapses that could be the early stages of Alzheimer’s.

Any higher than this and the person may already have it. Writing in the journal BMC Geriatrics researcher Michael Malek-Ahmadi said: “As the population ages, the need for a quick method of spotting the disease early will grow.”