Apathy in old age may be a sign of degenerative brain changes, according to a recent study Fox News reported.

Researchers from the National Institute of Aging at the National Institutes of Health in Bethesda, Md., found that older people with a lack of interest or emotion are more likely to have smaller brain volumes.

They found that people who demonstrated two or more apathy symptoms had 1.4 percent smaller gray matter volume - learning and memory storage - and 1.6 percent less white matter volume - communication cables, connecting different parts of the brain - compared to people who displayed less than two symptoms of apathy, Fox News reported.

"Just as signs of memory loss may signal brain changes related to brain disease, apathy may indicate underlying changes," study author Lenore J. Launer, head of the neuroepidemiology unit at the NIH, said in a press release.

For the study, researchers studied a group of more than 4,300 people with an average age of 76. Each participant underwent an MRI scan and took a questionnaire that measured apathy symptoms, which can include lack of emotion, lack of interest, giving up activities and interests, choosing to stay at home and lacking energy.

"The changes are generally thought to reflect neurodegeneration (i.e. dying neurons) in the gray matter and vascular disease- which leads to white and gray matter damage," Launer told Fox News. "These pathologies do increase with age, but the hypothesis is they represent disease processes that can be prevented or reduced."

Fox news reported that Launer's research focuses on understanding risk factors for and consequences of processes leading to late-life dementia.

"If these findings are confirmed, identifying people with apathy earlier may be one way to target an at-risk group," Launer said.

The findings were recently published in the journal Neurology.