July 1, 2010
Elderly men and women who are worried about memory loss are more likely to develop more serious memory and thinking problems, including Alzheimer's disease, than their age-matched peers without memory problems, a new study reports. The findings are consistent with earlier research that the development of Alzheimer's is a years-long process, with cognitive skills deteriorating until full blown Alzheimer’s dementia takes hold.
Mild cognitive impairment, or MCI, is a brain problem that impairs memory or other cognitive functioning but does not prevent activities of daily living like dressing, personal hygiene, eating or going about daily activities. It has long been recognized as a potential precursor to the more severe impairment of Alzheimer's disease. Some 10 percent to 20 percent of people with MCI, particularly those with memory problems progress to a diagnosis of full-blown Alzheimer's each year. While MCI is a potential problem, it must also be remembered that memory impairment can also be caused by factors other than Alzheimer’s and may be treatable.
“The concept of mild cognitive impairment as a predementia manifestation of Alzheimer’s disease is substantiated by studies providing biologic evidence for the presence of Alzheimer’s disease in patients with mild cognitive impairment,” the authors, part of the German Study on Aging, Cognition and Dementia in Primary Care Patients Study Group, wrote. “However, Alzheimer’s disease–related pathologic changes in the brain evolve several years before the onset of mild cognitive impairment.”
The current study, conducted in Germany, looked at 2,415 elderly men and women, ages 75 and up who were mentally intact at the start of the study. Some had mild memory problems, but none had memory loss that was severe enough to qualify as MCI or Alzheimer's disease. Indeed, many older people complain about "senior moments" and forgetting things like names and where they put the car keys.
Study participants were asked whether they believed their memory was becoming worse and whether or not this caused worry for them -- one way for researchers to gauge the severity of memory impairments. They were then given follow-up exams one and a half and three years later to test for mild cognitive impairment and dementia, including Alzheimer's disease.
Among the elderly men and women with memory problems, some expressed high levels of concern about their memory loss. The researchers found that those who were worried about their fading memory were twice as likely to progress to more advanced stages of memory impairment than those who did not express concern about their memory problems.
“Subjective memory impairment without worry was independently associated with increased risk for dementia,” the authors wrote. “This risk was roughly doubled by the presence of subjective memory impairment–related worry.”
Individuals who had memory impairment with concern at the beginning of the study were at the highest risk for conversion to any dementia, including Alzheimer’s dementia, at either follow-up.
In addition, having memory impairment at the beginning of the study and mild cognitive impairment at the first follow-up increased the risk of progression to Alzheimer’s disease at the second follow-up; these individuals had the greatest risk for developing dementia.
The findings, published in the Archives of General Psychiatry, a medical journal from the American Medical Association, point to the growing awareness that memory loss is often progressive and may precede the onset of Alzheimer's by years.
Not all subjects with subsequent dementia will experience or report subjective memory impairment at the pre-MCI stage.
Anyone concerned about memory should talk to their doctor about their concerns. Stress, medications, aging and other factors can all impair memory, and steps such as adjusting medications can be taken to restore memory in many seniors who are having problems. In addition, it's important to note that having memory problems by no means mean that Alzheimer's or other forms of dementia will eventually develop.
Frank Jessen; Birgitt Wiese; Cadja Bachmann; et al: "Prediction of Dementia by Subjective Memory Impairment: Effects of Severity and Temporal Association With Cognitive Impairment." Archives of General Psychiatry, Vol. 67(4): April 2009, pages 414-422.