CAMBRIDGE, United Kingdom — Apathy can be a dangerous warning sign for many conditions tied to mental health. While the loss of interest and motivation typically signals the onset of depression, hormone changes, or other mental conditions, a new study finds it may also be a red flag for dementia. Researchers from the University of Cambridge say feelings of apathy can predict if someone will develop dementia years before symptoms like memory loss ever appear.
Frontotemporal dementia is one of the leading causes of dementia in younger patients. Doctors typically diagnose the condition in patients between 45 and 65 years-old. This form of cognitive decline can also affect behavior, language, and personality. Patients can begin to act more impulsively and engage in inappropriate or compulsive behavior.
One of the common threads in frontotemporal dementia cases is patients become apathetic, losing interest in things they normally do. Researchers say this isn’t depression, even though physicians may mistake it for another condition. The study finds frontotemporal dementia is triggered by shrinkage in particular regions in the front of the brain. The worse the shrinkage gets, the more apathetic patients become. While this will eventually lead to cognitive decline, study authors say the process can begin years and possibly decades before dementia becomes visible.
“Apathy is one of the most common symptoms in patients with frontotemporal dementia. It is linked to functional decline, decreased quality of life, loss of independence and poorer survival,” says Maura Malpetti, a cognitive scientist at Cambridge’s Department of Clinical Neurosciences, in a university release.
“The more we discover about the earliest effects of frontotemporal dementia, when people still feel well in themselves, the better we can treat symptoms and delay or even prevent the dementia.”
‘Brain shrinkage in areas that support motivation and initiative’
The study reveals that frontotemporal dementia can be a genetic condition. Nearly a third of patients with this form of dementia have family members who also had it too.
Researchers examined 304 healthy people who carry a faulty gene which can trigger frontotemporal dementia and 296 members of their family who have normal genes. The study followed each person for several years and most of the patients didn’t know whether they had the gene abnormality or not. Researchers monitored each person for changes in apathy, memory, and took MRI scans of their brains.
“By studying people over time, rather than just taking a snapshot, we revealed how even subtle changes in apathy predicted a change in cognition, but not the other way around,” Malpetti explains. “We also saw local brain shrinkage in areas that support motivation and initiative, many years before the expected onset of symptoms.”
Apathy’s impact on the brain
The results reveal that people with this genetic mutation display more apathy than their relatives who don’t carry the defect. Over two years, this behavior increased significantly more than in people with normal genes. Apathy also predicted the onset of cognitive decline as patients approached the typical age dementia symptoms tend to appear.
“Apathy progresses much faster for those individuals who we know are at greater risk of developing frontotemporal dementia, and this is linked to greater atrophy in the brain. At the start, even though the participants with a genetic mutation felt well and had no symptoms, they were showing greater levels of apathy. The amount of apathy predicted cognitive problems in the years ahead,” Professor Rogier Kievit says.
“From other research, we know that in patients with frontotemporal dementia, apathy is a bad sign in terms of independent living and survival. Here we show its importance in the decades before symptoms begin,” adds joint senior author Professor James Rowe.
Prof. Rowe says the study shows why it’s important to not only find out if someone is displaying apathy, but why they’re feeling this way.
“There are many reasons why someone feels apathetic. It may well be an easy to treat medical condition, such as low levels of thyroid hormone, or a psychiatric illness such as depression. But doctors need to keep in mind the possibility of apathy heralding a dementia, and increasing the chance of dementia if left unaddressed, particularly if someone has a family history of dementia,” he concludes.
“Treating dementia is a challenge, but the sooner we can diagnose the disease, the greater our window of opportunity to try and intervene and slow or stop its progress.”
The study appears in the Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.