Memory problems are a worrisome symptom, and, especially for older adults, they’re often seen as the main symptom of Alzheimer’s and other types of dementia. However, a recent study suggests that these symptoms aren’t always heralding the onset of dementia. In fact, sometimes they can even go away on their own.
The study was meant to help researchers better understand the most important risk factors for dementia among the diversity of the American population.
“We wanted to gain more knowledge about the earliest stages of dementia, as a potential time window for dementia prevention or intervention strategies,” says study lead author Jennifer Manly, a professor of neuropsychology at Columbia University in New York City. “Most prior MCI studies are conducted among only non-Hispanic white older adults who seek help from a doctor who specializes in memory disorders.”
Researchers followed more than 2,900 participants with an average age in the mid-70s for about six years. During that time, 752 were diagnosed with mild cognitive impairment (MCI) after reporting problems with memory or thinking and taking a test to determine their level of impairment. All of the participants were still well enough to complete their normal daily tasks. They reported problems with completing fewer than three of their daily tasks; common tasks to struggle with included shopping and remembering to take medications.
480 of those diagnosed with MCI took a follow-up test two years after diagnosis. 13 percent of them had gone on to develop dementia. 30 percent still had MCI but had not developed dementia, and roughly 10 percent had seen a mental decline but not enough to be diagnosed with dementia. But the real surprise was the other nearly 48 percent, who no longer had MCI.
These 48 percent were declared “cognitively normal” and no longer met the three criteria for MCI.
Manly says the research underscores the fact that people with MCI are not all the same, nor does the condition always occur due to the same cause. The predictors of MCI are also not always the same as the predictors for dementia. Therefore, not all people with MCI will see their impairment degrade into dementia.
MCI, according to Manly, should not be seen as the first sign of dementia or a precursor to dementia, but rather a “higher risk classification.”
Researchers also gathered data on the risk factors for MCI to help inform people about what they can do to prevent cognitive impairment. They found that having more education and taking part in healthier leisure activities such as reading, visiting friends, or walking. These activities reduced the risk of MCI by about five percent. Higher incomes appear to play a role as well.
There were also several factors that contributed to the risk of MCI devolving into dementia. These factors included the use of antidepressants, having symptoms of depression, having the particular gene that increases Alzheimer’s risk, and having MCI that affects several aspects of thinking skills, including memory, language, and spatial skills.
“I think it just confirms that people with mild cognitive impairment are a heterogeneous group, that some people are in fact on the Alzheimer’s disease or dementia path, and some people are having mild cognitive impairment because of other things that are potentially reversible like depression, poor sleep, for example having obstructive sleep apnea,” says Dr. Zaldy Tan, director of the Memory and Aging Program for Cedars-Sinai in Los Angeles.
“Some of these things can interfere with memory, and someone can have a subjective complaint of a memory problem but may not necessarily have the pathology for dementia.”
Manly says the study’s results could help inform health initiatives in the future to help the public modify their own risk factors and stave off MCI and dementia.
The findings were published in the journal Neurology. Researchers say their work was limited by a short follow-up time, but they hope future research can corroborate their results.
If you believe you may have problems with your memory or thinking, please contact your doctor to ask about your screening options.
“The primary physician will be the best judge of whether they need further evaluation through memory testing or neuroimaging or neuro-psychological testing,” Tan says.