Alzheimer's Diagnosis: Disease May Start 18 Years Before Symptoms Appear

June 24, 2015 4:00 PM EDT

The latest breakthroughs in Alzheimer’s research focus on the time well before patients even know they might have the neurodegenerative condition. Studies so far have found evidence that the biological processes that cause the mental decline may begin 10 to 12 years before people first notice signs of cognitive decline. But in the most recent report published Wednesday in the journal Neurology, experts say that the disease may actually begin even earlier — 18 years earlier, in fact — than they expected.

MORE: Mental and Social Activity Delays the Symptoms of Alzheimer’s

For 18 years, Kumar Rajan, associate professor of internal medicine at Rush University Medical Center, and his colleagues followed 2,125 elderly people with an average age of 73 and who did not dementia. Every three years, the researchers gave the volunteers mental skills tests, and then compared these results over time.

When the looked at the group that went on to receive an Alzheimer’s diagnosis, they found that these people showed lower scores on their tests throughout the study period. In fact, their scores steadily declined with each test. For each unit that the scores dropped on the cognitive tests, the risk of future Alzheimer’s increased by 85%.

Into Oblivion: Documenting the Memory Loss from Alzheimer’s

A resident stands in front of the ward’s locked exit door. Passages are blocked and doors are locked to prevent residents from wandering off. Photographer Maja Daniels spent three years, beginning in 2008, documenting the ward and its residentsMAJA DANIELS

A resident’s room in the Alzheimer's ward. Many people suffering from Alzheimer’s disease live in institutions today. The number of individuals above the age of 60 is expected to double over the next 25 years. While more and more people are in need of care, fewer professionals choose to enter the geriatric sector MAJA DANIELS

A resident in the Alzheimer’s ward expressing confusion and anxiety. A person can live with Alzheimer’s disease for about 10 years while a constant degradation of memory and an increasing loss of contact to the outside world can be observed MAJA DANIELS

A resident stands in front of the locked ward door MAJA DANIELS

Walls in a resident's room of the Alzheimer's ward MAJA DANIELS

A resident stops in front of a wall in the Alzheimer’s ward. A common symptom for Alzheimer’s disease is sudden immobilization or fixationMAJA DANIELS

A resident lies in bed in the Alzheimer’s ward. Most residents in the ward have reached a state in which they have lost most of their communication skills and few even recognize family members MAJA DANIELS

A wandering resident reaches the ward’s locked exit door MAJA DANIELS

Jesus in a staircase window of the Alzheimer’s ward MAJA DANIELS

A resident in the common room of the Alzheimer’s ward MAJA DANIELS

Two residents stand in front of the ward’s locked exit doorMAJA DANIELS

A resident of the Alzheimer’s ward falls asleep during breakfast MAJA DANIELS

A resident stands in front of the ward’s locked exit door MAJA DANIELS

Soup and apple juice in the Alzheimer's ward MAJA DANIELS

A resident’s room in the Alzheimer’s ward MAJA DANIELS

A resident sits in the ward's common room. She is talking aloud to someone the photographer cannot see. The age-related disease is a mystery as very little is known about its causes. There is no cure for Alzheimer’s disease although medication has been proved to slow down the developing process of the symptoms MAJA DANIELS

Evidence of a difficult night at 7 a.m. in a room in the Alzheimer’s ward. Alzheimer’s disease can cause behaviour difficulties such as aggressiveness, eating disorders, increased anxiety or depressive tendencies MAJA DANIELS

MORE: Many Doctors Don’t Tell Patients They Have Alzheimer’s

Rajan stresses that the results only link cognitive testing scores on broad, group-level risk, and can’t be used to predict an individual’s risk of developing the disease. For one, more research will be needed to find the range of decline that signals potential Alzheimer’s dementia. But the findings do set the stage for studying whether such a non-invasive, easily administered test can, or should be, part of a regular assessment of people’s risk beginning in middle-age.

That way, he says, people may have a longer time period in which to hopefully intervene to slow down the disease process. Rajan plans to study whether brain-stimulating activities like crossword puzzles or learning a new language and social interactions can improve the test scores, and in turn slow the time to diagnosis of Alzheimer’s. At the very least, he says, the current data shows that there is a longer window of time in which people might be able to intervene in these ways and potentially delay Alzheimer’s most debilitating effects.

Alzheimer’s May Begin 20 Years Before Symptoms Appear

Into Oblivion: Documenting the Memory Loss from Alzheimer’s

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