A new study in the journal Neurology, older women who complain of poor memory may be have higher risk for cognitive impairment almost 20 years later.

Study co-author Alison Kaup, PhD, of the University of California-San Francisco and the San Francisco VA Medical Center, noticed previous studies to have suggested memory complaints among older women can be an early sign of Alzheimer's disease or other memory and thinking disorders. However, she added that their study is different from others because they have followed these women for over 20 years.

The study involved a thousand women aged 65 and older who were dementia free at the baseline. The memory problems of each subject were checked with one question asked several times over an 18-year period: "Do you feel you have more problems with memory than most?" Participants were required to answer only with a "yes" or "no."

At the beginning of the study, 8% of the total women complained of memory problem. The researchers defined it to be serious for these women to notice it themselves but not serious enough to be noted by the standard memory test. Compared to women who reported no memory problems at study baseline, those who complained were at 70% greater risk of being diagnosed with a memory and thinking disorder almost 2 decades later.

Women who revealed memory problems 10 years prior to the end of the study were 90% more likely to be diagnosed with a cognitive impairment, as those who reported no memory problems 10 years previously. According to the results, memory complaints that occurred 4 years before the end of study were linked to a three times greater risk of being diagnosed with cognitive impairment by the end of the study.

The researchers say their findings give further proof that memory complaints in older adults should receive immediate attention, as they could be an early sign of a more serious memory and thinking problems later in life.