Measuring neuropsychiatric symptoms such as depression, anxiety, agitation and irritability can help predict who will develop mild cognitive impairment, and who will progress to dementia or revert back to normal cognition.

So found researchers from Boston University School of Medicine, who recently published a data analysis on depression and cognition in the Journal of Alzheimer’s Disease. They tracked 6,763 individuals participating in longitudinal research studies at 34 Alzheimer’s Disease Centers across the U.S., all of whom received annual neurologic examinations and evaluations of their memory and cognitive functioning as well as any neuropsychiatric symptoms. They participated from 2 to 12 years.

The study showed individuals with normal cognition were more likely to progress to MCI if they had more depression, anxiety and other mood symptoms. Similarly, people who progressed to MCI were more likely to develop dementia if they had more of these neuropsychiatric symptoms.

But about one-third of the participants who progressed to MCI reverted back to normal cognition, and those participants had significantly lower neuropsychiatric symptoms and a greater reduction in depression symptoms.

The researchers reported evaluation and treatment of symptoms of depression may improve or maintain cognitive functioning in some older patients diagnosed with MCI.

MCI is a state in between normal cognition and Alzheimer’s disease dementia, in which the individual has a subjective complaint of memory and other cognitive difficulties and performance on formal neuropsychological testing is abnormal for age, but these problems do not interfere with routine independent functioning. The majority of people with MCI have progressive memory and cognitive impairment, and eventually are unable to function independently with daily tasks.

“The implication is that successfully identifying and providing effective treatment for these neuropsychiatric symptoms, including depression, may potentially improve or maintain cognitive functioning in many older adults,” explained corresponding author Robert Stern, Ph.D., Clinical Core Director of the Boston University Alzheimer’s Disease Center.