For some elderly people, apathy may signal that the brain is shrinking a bit faster than normal, a new study suggests.
The brain naturally gets smaller as people age, but according to the results of the study, an unusual amount of brain shrinking that is associated with apathy could indicate diseases of the brain. Identifying people with apathy earlier may help doctors find people at risk of brain diseases, the researchers said.
"This study indicates that apathy, which is a motivational condition, is prevalent in older persons," said study author Lenore J. Launer,chief of neuroepidemiology at the National Institutes of Health (NIH) in Bethesda, Md. "Severalneuropsychiatric diseases are accompanied by apathy, the most common being Alzheimer's disease, Parkinson's disease and stroke."
However, because the study looked at people at only one point in time, it does not indicate which came first, the apathy or the brain changes, Launer said. Many brain diseases start to develop long before a person shows symptoms, she told Live Science. [10 Ways to Keep Your Mind Sharp ]
The study is published online today (April 16) in the journal Neurology.
In the research, about 4,400 people without dementia, whose average age was 76, underwent a magnetic resonance imaging scan (MRI) to measure both gray- and white-matter volume in the brain. Gray matter is associated with memory, emotion, conscious thought, moving muscles and perceiving sensory information, while white matter connects brain regions and enables communication between them.
Researchers also asked questions designed to gauge the participants' apathy, which can be characterized by a lack of emotion, loss of interest in activities, reduced energy levels and a preference to stay at home rather than socialize. People with two or more apathy symptoms were found to have 1.4-percent smaller gray-matter volume and 1.6-percent less white-matter volume, compared with those who had fewer than two symptoms of apathy. Excluding people with depression symptoms from the study did not alter the results, the researchers said.
"If someone thinks their partner or a relative shows a lack of motivation to perform even routine activities, exhibits a lack of interest or lack of emotions, or shows no interest in doing new things, in the absence of emotional distress or cognitive impairment, he or she should be examined by a clinician," Launer said.
Dr. Joe Verghese, professor of neurology and chief of the division of geriatrics at Albert Einstein College of Medicine in New York, said that although apathy can occur at any age, this study is significant because the researchers looked at apathy linked with physical brain matter loss, in a specific group of people.
The study "is an important step in understanding the connection between apathy and loss of brain matter," Verghesesaid. "It's too preliminary, however, to say if apathy is a predictor of dementia in older adults."
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