The researchers from five medical centers including Wake Forest University Baptist Medical Center reported in the current Journal of the American Medical Association that their study, based on participants followed for more than 10 years, was the first to show that the appearance of psychiatric symptoms correlate with the development of mild cognitive impairment.
While psychiatric symptoms occur in the majority of persons with outright dementia, "these are the first population-based estimates for neuropsychiatric symptoms in mild cognitive impairment," the group reported. "These symptoms have serious adverse consequences and should be inquired about and treated as necessary."
"Patients complaining of memory loss should be questioned about other symptoms such as depression, irritability, loss of interest in activities, or changes in sleep or appetite," said Beverly N. Jones III, associate professor of psychiatry and behavioral medicine (geriatric psychiatry), at Wake Forest, one of the report's authors. "It is important to recognize that these symptoms may be due to changes in brain function, not just emotional reactions to memory decline, and can respond to treatment."
The investigation was a corollary of the Cardiovascular Health Study (CHS), the largest study ever of the evolution of heart disease and stroke among people over 65 years old. Beginning in 1989, the study enrolled 5,888 participants in roughly equal numbers in four geographically dispersed counties, including Forsyth County (Winston-Salem), N.C., and brought them back annually for follow-up examinations to determine progression of cardiovascular diseases. The study was observational, so clinical conditions were referred to the participant's own doctor for treatment.
The opportunity for the CHS Cognition Study occurred because 3,660 participants had had an MRI examination of the brain between 1991 and 1994 and 3,608 had completed an evaluation of memory known as the Modified Mini-Mental State Examination at the same time. They became the cognition study population.
The researchers found that 43 percent of the participants with mild cognitive impairment had psychiatric symptoms in the month before examination. Among the patients with dementia, 75 percent had had psychiatric symptoms such as apathy, depression and agitation/aggression in the previous month.
The researchers also noted that effective drugs are available for treating most of the symptoms, which are "likely to provide substantial benefits to patients and caregivers." But, they said, primary care doctors often miss early symptoms of dementia and mild cognitive impairment. "Neuropsychiatric symptoms are often not recognized until they have become severe leading to hospitalization or institutionalization."
The lead author for the study was Constantine G. Lyketsos of Johns Hopkins University. The study was supported by grants from the National Heart, Lung and Blood Institute.