Severe apathy — a lack of interest and loss of desire to participate in daily activities — is tied to greater odds of developing dementia, a nine-year study has found.

At year six, investigators evaluated more than 2,000 participants in the Health, Aging, and Body Composition study for self-reported symptoms of apathy, distinguished from depression and anxiety. Volunteers were then grouped according to level of apathy. 

Over the study’s full nine-year period, dementia developed in 381 participants. Dementia was determined based on medication use data, hospital records and clinically relevant cognitive decline in memory and thinking, although it was not necessarily diagnosed by a physician in all cases.

Results showed that people with severe apathy were at a higher risk of dementia when compared with those in the low apathy group (25% versus 14%). Greater apathy also was tied to a worse cognitive score at six-years, although not measured rate of cognitive change over time, reported Meredith A. Bock. M.D., of the University of California, San Francisco.

The findings were adjusted for demographics, cardiovascular risk, genetic risk, and depressed mood.

The study, published in the journal Neurology, offers new evidence that apathy may be an early symptom of dementia, Bock and colleagues concluded. 

People with apathy often lack interest in the world around them. Some will stop taking part in normal activities, show little emotion and have a notable lack of energy.