Could being apathetic cause a person’s brain to shrink? A new study has found that having no enthusiasm about life or people is linked to having a smaller brain. Researchers in Iceland interviewed more than 4,300 adults who were mostly in their 70’s, asking them three questions to gauge whether or not they had apathy. The questions asked whether subjects had dropped many of their activities or interests, whether they preferred to stay at home instead of going out and doing new things, and whether they felt “full of energy.”
Almost half of all participants had 2 or 3 of these signs of apathy; the subjects then underwent MRI scans to measure brain volume. Researchers found that subjects who had at least two of the above symptoms had 1.4% less gray matter and 1.6% less white matter than subjects who had fewer than two apathy symptoms. Gray matter is where information and memories are stored and where the brain interprets stimuli from the rest of the body; white matter is where the neuron cells that connect the different sections of gray matter are located.
Researchers were quick to point out that the experiment did not prove cause-and-effect. That is, apathy may not be what causes the brain to shrink; rather, apathy could be a symptom of a developing condition that is not yet apparent, such as Alzheimer’s; people with Alzheimer’s often also display apathy.
Apathy can also be a symptom of depression, but the study found that apathy was linked to lower brain volume even when subjects were not depressed. The researchers also took into account other factors like diabetes, high blood pressure, smoking, exercise levels and walking speeds, and they found that apathy was still linked to lower brain volume.
The human brain is known to get smaller as we age; but that shrinkage can be accelerated in people who are starting to develop different types of dementia or Parkinson’s disease, according to a doctor who did not participate in the study. Researchers in the study stated that doctors should consider apathy as a possible symptom of illness that may be developing in the brain. However, to determine whether apathy alone can shrink the brain, a long-term study would need to be done.
Earlier research had found that older people with depression can develop “white matter lesions,” which are small areas of dead cells in the brain. People who have cognitive impairment such as that from Alzheimer’s disease, and who also have apathy, have been found to have increased levels of white matter lesions in the frontal lobe of the brain, as well as brain atrophy (shrinkage). That led researchers to wonder whether apathy could cause similar brain changes in people without dementia or depression.
The study was published recently online in the journal Neurology. Earlier this year, Medical News Today wrote about a study from Johns Hopkins University, which found that hearing loss in older adults may cause the brain to shrink faster.
By Marc Courtiol