A controversial study has linked the onset of dementia to specific personality traits.
Dementia is an umbrella term for a range of conditions that cause a decline in brain function, with Alzheimer’s being the most common.
Many forms of dementia are associated with an abnormal build-up of proteins in the brain, which cause nerve cells to die and different areas of the vital organ to shrink.
Exactly why this occurs is often unclear, however, it has been linked to strokes, as well as a family history of the disease.
Scientists from Northwestern University in Illinois recently found people who tend to be moody, anxious or impulsive may be “more likely to have worse cognitive function”.
Those who are self-disciplined, organised and motivated tend to have improved “cognitive resilience”, allowing them to live with the brain changes associated with dementia without its symptoms, they suggested.
Ageing brains naturally collect tangles and plaques that can interfere with thinking and memory.
This is different from Alzheimer’s, which comes about when a protein called amyloid forms plaques around brain cells, as well as the protein tau creating tangles within the cells.
Alzheimer’s aside, different elderly people vary in their ability to maintain their “cognitive reserve” while having these plaques and tangles.
To uncover whether personality traits influence this, the Northwestern scientists analysed 1,375 deceased people who took part in the Religious Orders Study and the Rush Memory and Aging Project.
Years worth of data was available on the participants’ personalities and cognitive function, as well as autopsies revealing their neuropathology – the study of disease in nervous system tissue.
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Results – published in the Journal of Gerontology: Psychological Sciences – suggest the participants who had a greater tendency towards self-discipline, organisation, diligence, achievement and motivation experienced a higher level of “cognitive resilience”.
This is defined as the ability to live with the neuropathology that causes dementia, without severe symptoms.
The participants with “higher neuroticism” – a tendency towards anxiety, worrying, moodiness and impulsivity – had worse cognitive function than expected given the neuropathology detected at autopsy, suggesting lower cognitive resilience.
“These findings provide evidence it is possible for older adults to live with the neuropathology associated with Alzheimer’s disease and related dementias while maintaining relatively healthy levels of cognitive function,” said lead author Dr Eileen Graham.
“Our study shows personality traits are related to how well people are able to maintain their cognitive function in spite of developing neuropathology.
“Since it is possible for personality to change, both volitionally and through interventions, it’s possible personality could be used to identify those who are at risk and implement early interventions to help optimise function throughout old age.”
Dementia affects 850,000 people in the UK, which is expected to rise to 1.6 million by 2040.
In the US, 5.7 million people live with the disease.
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