Although older patients often complain of cognitive deficits, it is uncertain whether such complaints have clinical significance. Dufouil and colleagues examined whether increased cognitive complaints reflect previous or future cognitive decline.
The authors used data from the population-based, longitudinal Epidemiology of Vascular Aging study. Participants were 59 to 71 years of age. Patients received a baseline examination, were reexamined after four years, and were examined annually thereafter.
The four-year questionnaire was completed by 733 participants. One half of the study participants completed the Cognitive Difficulties Scale, which rates subjective cognitive complaints, at the four-year follow-up examination. They also were tested for objective cognitive function using the Mini-Mental State Examination. Selected participants received magnetic resonance imaging to identify the presence of white matter hyperintensities. All participants also were evaluated for depression using the Center for Epidemiological Studies Depression Scale.
Higher degrees of cognitive complaints were associated with depression, use of psychotropic medication, and lower education level. They also were associated with greater cognitive decline at the four-year follow-up, a correlation that was independent of depressive symptoms. At the six-year follow-up, 555 of the 733 persons who completed the questionnaire two years earlier were examined. There was a greater cognitive decline in participants who had had more cognitive complaints. This held true even in those who had not had any objective cognitive decline from baseline to four years and regardless of whether they did or did not have identifiable cognitive deficit at four years. Participants with severe white matter changes and higher cognitive complaints had greater cognitive decline than other patients.
The authors conclude that cognitive complaints predict cognitive decline, and this occurs independently of baseline cognitive status. They also found that complaints reflect previous cognitive decline. Thus, cognitive complaints may be more sensitive than findings on objective measures, and such complaints should be taken seriously.