Alzheimer's disease is something most of us would rather not think about — our memories and our identity slowly slipping as we age. But recent breakthroughs have shown significant hope, making diagnosis and early detection possible in the future. One past study showed a causal link between poor sleep and the disease later on in life. A new study suggests that errors in memory and thinking tests could be a red flag for Alzheimer's up to 18 years in advance.

Kumar B. Rajan, from the Rush University Medical Center in Chicago, led the study, which has been published in the journal Neurology.

He said in a press release that his findings suggest:

"The changes in thinking and memory that precede obvious symptoms of Alzheimer's disease begin decades before. 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."

The study consisted of 2,125 participants with an average age of 73 — all without Alzheimer's disease when the study began. For the next 18 years, every three years, the participants were given an exam, which tested their memory and thinking. The researcher reported that a total of “442 (21 percent) developed clinical [Alzheimer's disease] dementia over 18 years of follow-up.”

Over the course of the study, the researcher found “[p]erformance on individual cognitive tests of episodic memory, executive function, and global cognition ... significantly predicted the development of [Alzheimer's] dementia, with associations exhibiting a similar trend over 18 years.” Their study shows substantial evidence that the symptoms of Alzheimer's disease may manifest substantially earlier than previously thought.

Rajan said:

"A general current concept is that in development of Alzheimer's disease, certain physical and biologic changes precede memory and thinking impairment. 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."

Read more about the study at Science Daily.

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