Teacher:In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Teacher: Now, understand the problem? Solve this instance: By Mary Elizabeth Dallas, HealthDay Reporter 
  
 (HealthDay) 
  
 WEDNESDAY, June 24, 2015 (HealthDay News) -- Mistakes made on memory and thinking tests may be early warning signs of Alzheimer's disease, researchers report. 
  
 Low scores on such tests could serve as a "red flag" for the progressive brain disease up to 18 years before it can be diagnosed, the study authors added. 
  
 "The changes in thinking and memory that precede obvious symptoms of Alzheimer's disease begin decades before," study author Kumar Rajan, of Rush University Medical Center in Chicago, said in a news release from the American Academy of Neurology. 
  
 "While we cannot currently detect such changes in individuals at risk, we were able to observe them among a group of individuals who eventually developed dementia due to Alzheimer's," Rajan said. 
  
 The study involved more than 2,000 black and white people from Chicago. The participants were an average age of 73. None were diagnosed with Alzheimer's at the start of the study, and each completed tests of memory and thinking skills every three years over nearly two decades. 
  
 During the study period, 23 percent of the black people and 17 percent of the white people developed Alzheimer's. Those who had the lowest test scores were at greater risk for the disease. 
  
 After the first year, those with lower test scores were about 10 times more likely to develop Alzheimer's than those with the best scores. These odds increased as the scores dropped below average, the study published online June 24 in the journal Neurology found. 
  
 "A general current concept is that in development of Alzheimer's disease, certain physical and biologic changes precede memory and thinking impairment," Rajan said. "If this is so, then these underlying processes may have a very long duration. Efforts to successfully prevent the disease may well require a better understanding of these processes near middle age." 
  
 More information 
  
 The U.S. National Institute on Aging has more about Alzheimer's disease. ||||| Objective: To examine the relation of performance on brief cognitive tests to development of clinically diagnosed Alzheimer disease (AD) dementia over the following 18 years in a sample of African Americans and European Americans. 
  
 Methods: A composite cognitive test score based on tests of episodic memory, executive function, and global cognition was constructed in a prospective population-based sample of 2,125 participants (55% African American and 61% female) aged 65 years and older residing in 4 Chicago neighborhoods. Time before AD dementia diagnosis was categorized into 6 groups corresponding to data collection periods: 0.1–0.9, 1.0–3.9, 4.0–6.9, 7.0–9.9, 10.0–12.9, and 13.0–17.9 years. 
  
 Results: Of 2,125 participants without clinical AD dementia, 442 (21%) developed clinical AD dementia over 18 years of follow-up. Lower composite cognitive test scores were associated with the development of AD dementia over the duration of the study. The magnitude of association between composite cognitive test score and development of AD dementia increased from an odds ratio of 3.39 (95% confidence interval 1.72, 6.67; p < 0.001) at 13.0–17.9 years to 9.84 (95% confidence interval 7.41, 13.06; p < 0.001) at 0.1–0.9 years, per SD increment. These associations were consistently larger among European Americans than among African Americans. Performance on individual cognitive tests of episodic memory, executive function, and global cognition also significantly predicted the development of AD dementia, with associations exhibiting a similar trend over 18 years. |||||  
  
  
  
 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%. 
  
 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. |||||
Student:
A new study suggests a relatively easy way to gauge whether people are more likely to wind up with an Alzheimer's diagnosis as far as 18 years down the road: memory and thinking tests. A study out of the Rush University Medical Center in Chicago tracked more than 2,000 people with an average age of 73 who did not have an Alzheimer's diagnosis when the study began, explains HealthDay News. They took mental skills tests every three years over a nearly two-decade span, and it turns out that those who scored low on the tests had a greater chance of being diagnosed with Alzheimer's. At the time they took the tests, though, they showed no obvious symptoms of looming trouble, save for those low test scores. What's more, the eventual Alzheimer's patients showed progressively worse results in the testing. "The changes in thinking and memory that precede obvious symptoms of Alzheimer's disease begin decades before," says Kumar Rajan, author of the study in Neurology. He says the findings should be interpreted generally—that low test scores shouldn't be used to predict an individual's risk. But such tests might someday become a routine part of health maintenance for those in middle age, notes Time. For those who fare poorly, it might be wise to try to take preventative efforts. Rajan plans to next study what some of those efforts might be, perhaps even simple things such as crossword puzzles or increased social interaction. (In the meantime, those who snore might be at greater risk, too.)