Apathy unproven as early warning sign of dementia

“Elderly who lose interest in pastimes could be at risk of Alzheimer's,” reports The Daily Telegraph, with other papers reporting similar headlines.

These incorrect headlines are based on the results of a study that looked for a link between symptoms of apathy and structural brain changes (on brain scans) in over 4,000 older adults who did not have dementia.

The researchers were interested in discovering whether there were a combination of changes in brain volume and reported symptoms of apathy.

These symptoms were defined as:

giving up activities and interests
preferring to stay at home rather than going out and doing new things
not feeling full of energy

People who reported two or more of the symptoms listed above had significantly smaller total brain volume and grey and white matter volumes, compared to their counterparts.

Our grey matter contains predominantly nerve cell bodies – it is also where memories are stored and where learning takes place in the brain. White matter contains nerve cell fibres and is responsible for communication between different brain regions. People with symptoms of apathy also had more abnormal changes to their white matter.

As symptoms of apathy and structural brain changes were assessed at the same time, we don’t know if the two are directly related or if there are other factors at play.

It’s currently unproven whether keeping both the mind and the body active will prevent dementia, but it can help improve a person’s quality of life.

Where did the story come from?

The study was carried out by researchers from the University Medical Centre Utrecht in the Netherlands; the National Institute on Aging and the Laboratory for Epidemiology, Demography and Biometry in the US; and the Icelandic Heart Association, the University of Iceland, Janus Rehabilitation and Lanspitali University Hospital in Iceland. It was funded by a US National Institutes of Health contract, the US National Institute on Aging Intramural Research Programme, Hjartavernd (the Icelandic Heart Association) and Althingi (the Icelandic Parliament).

The study was published in the peer-reviewed journal Neurology.

This story was covered by The Independent, the Daily Mail and The Times. The Mail and The Independent’s coverage was poor, with both newspaper’s reporting that losing interest in hobbies and other activities in old age could be an early sign of dementia or Alzheimer’s. This study did not investigate whether symptoms of apathy were linked to Alzheimer’s or other dementias. Instead, it looked for a link between apathy symptoms and structural brain changes at a particular point in time.

The Times’ coverage was more measured, as it stressed that a direct causal link between apathy, brain size and dementia risk had not been proven by the study.

What kind of research was this?

This was a cross-sectional study of 4,354 older people without dementia who were participating in the Age, Gene/Environment Susceptibility-Reykjavik Study. It aimed to discover if there was a link between apathy symptoms (lack of interest, enthusiasm or concern) and structural brain changes.

Cross-sectional studies only analyse people at one particular point in time. This means that we don’t know whether the appearance of apathy symptoms and brain changes happened at the same time or if one happened before the other. We also don’t know if the two things are directly related or if there are other factors associated with both.

What did the research involve?

The researchers studied 4,354 older people (with an average age of 76) without dementia who were participating in the Age, Gene/Environment Susceptibility-Reykjavik Study, which is an ongoing cohort study into the effects of ageing and genetics.

Apathy symptoms were assessed through responses to three items relating to apathy on the Geriatric Depression Scale. The three questions relating to apathy were:

Have you dropped many of your activities and interests?
Do you prefer to stay at home, rather than going out and doing new things?
Do you feel full of energy?

Brain volumes and total white matter lesions (abnormal changes in white matter) were measured from MRI scans [/conditions/MRI-scan/Pages/Introduction.aspx].

The researchers compared people with two or more apathy symptoms to those with fewer than two symptoms, to see if there were differences in brain volume and white matter lesions.

They adjusted their analyses for a wide variety of confounding factors including age, education, skull size, physical activity, depressive symptoms and antidepressant use

What were the basic results?

Just under half of participants (49%) had two or more symptoms of apathy. People with two or more symptoms were older and more likely to be women. They also had lower education, were less physically active, had poorer Mini-Mental State Examination Scores, walked slower and often had high blood pressure, mild cognitive impairment, brain infarcts and antidepressant use, as well as higher depression scores.

After adjusting their analyses for confounders, people with two or more apathy symptoms had significantly smaller total brain volume and grey and white matter volumes than those with fewer than two apathy symptoms. People with two or more symptoms had 0.5% less grey matter and 0.5% less white matter. They also had more white matter lesions.

Differences in grey matter volumes were particularly noticeable in the frontal and temporal lobes. These are two of the main brain regions, with the frontal lobe (at the front of the brain) involved with higher mental processes like thinking, judging and planning, and the temporal lobe at the sides of the brain (near the temples) involved with memory, hearing and language.

Differences in white matter volumes were particularly noticeable in the parietal lobe and the thalamus, both of which are involved in processing sensory information from the body.

How did the researchers interpret the results?
The researchers conclude that: “in this older population without dementia, apathy symptoms are associated with a more diffuse loss of both grey and white matter volumes”.

Conclusion

This cross-sectional study found that people who reported at least two symptoms of apathy had significantly smaller total brain volume and grey and white matter volumes than people with fewer than two apathy symptoms. The grey matter contains predominantly nerve cell bodies. It is also where memories are stored and where learning takes place in the brain. White matter contains nerve cell fibres and is responsible for communication between different brain regions. People with symptoms of apathy also had more abnormal changes to their white matter lesions.

As symptoms of apathy and structural brain changes were assessed together, we don’t know if the appearance of apathy symptoms and brain changes happened at the same time, or if one happened before the other. We also don’t know if the two things are directly related or if there are other factors associated with both.

This study has found that apathy symptoms are linked to brain changes. However, this study did not investigate whether apathy symptoms were associated with the development of Alzheimer’s or other types of dementia.

Currently, there is no guaranteed method to prevent dementia. However, evidence suggests that to reduce your risk some forms of dementia you should:

eat a healthy diet
maintain a healthy weight
exercise regularly
do not drink too much alcohol
stop smoking (if you smoke)
make sure you keep your blood pressure at a healthy level