In a new study, researchers found that apathy—a lack of interest or motivation—could predict the onset of some forms of dementia many years before symptoms start, offering a ‘window of opportunity’ to treat the disease at an early stage.
The research was conducted by a team at the University of Cambridge and elsewhere.
Frontotemporal dementia is a big cause of dementia among younger people. It is often diagnosed between the ages of 45 and 65.
It changes behavior, language, and personality, leading to impulsivity, socially inappropriate behavior, and repetitive or compulsive behaviors.
A common feature of frontotemporal dementia is apathy, with a loss of motivation, initiative, and interest in things. It is not depression or laziness, but it can be mistaken for them.
Brain scanning studies have shown that in people with frontotemporal dementia it is caused by shrinkage in special parts at the front of the brain—and the more severe the shrinkage, the worse the apathy.
But, apathy can begin decades before other symptoms and be a sign of problems to come.
Frontotemporal dementia can be genetic. About a third of patients have a family history of the condition.
The new discovery about the importance of early apathy comes from the Genetic Frontotemporal dementia Initiative (GENFI), a collaboration between scientists across Europe and Canada.
Over 1,000 people are taking part in GENFI, from families where there is a genetic cause of Frontotemporal dementia.
In the study, the team found how apathy predicts cognitive decline even before the dementia symptoms emerge.
The new study involved 304 healthy people who carry a faulty gene that causes frontotemporal dementia, and 296 of their relatives who have normal genes.
The participants were followed over several years. None had dementia, and most people in the study did not know whether they carry a faulty gene or not.
The researchers looked for changes in apathy, memory tests, and MRI scans of the brain.
They found people with the genetic mutations had more apathy than other members of their family, which over two years increased much more than in people with normal genetics.
The apathy predicted cognitive decline, and this accelerated as they approached the estimated age of onset of symptoms.
The finding showed apathy progresses much faster for those individuals who are at greater risk of developing frontotemporal dementia, and this is linked to greater atrophy in the brain.
The amount of apathy predicted cognitive problems in the years ahead.
The study highlights the importance of investigating why someone has apathy.
There are many reasons why someone feels apathetic. It may well be easy to treat a 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 dementia, and increasing the chance of dementia if left unaddressed, particularly if someone has a family history of dementia.
One author of the study is Professor James Rowe.
The study is published in Alzheimer’s & Dementia.
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