A buildup of amyloid plaques and tau protein tangles in the brain is associated with Alzheimer’s disease and related dementias. A new study reveals that being neurotic or conscientious can, respectively, increase or decrease the chances of developing these accumulations. Whether this association is the result of the lifestyles that characterize these personality types, however, is unclear.
Previous research has already found that certain personality traits are risk factors for Alzheimer’s disease and related dementias. However, scientists have not been able to find a causal link.
The development of amyloid plaques and insoluble tau protein tangles in the brain is also associated with the disease and related dementias. This new study now explores a possible link between personality traits and these health problems. The study reveals that neuroses increase the likelihood of developing amyloid plaques and tau tangles. Conversely, being conscientious reduces the likelihood of developing them.
Researchers at Florida State University’s Department of Geriatrics had previously done studies showing who is at risk of developing dementia. Here, the researchers were interested in neuropathology, that is, brain damage that tells us about the underlying pathological change. The study was published in the journal Biological Psychiatry.
Neuroticism and conscientiousness
Neuroticism and being maniacal or conscientious are two of the “big five” personality traits often cited by researchers and mental health experts. These traits appear early in life and, as the study says, “have a broad impact on important life outcomes.
The 5 main character traits
It is :
– Conscientiousness: This is a responsible, prudent and goal-oriented and detail-oriented person.
– Agreeableness: This describes a person who is respectful, compassionate, trusting and who tries to avoid problems.
– Neuroticism: Describes a person who revolves around destabilizing emotions, such as anxiety and depression.
– Openness: Describes a person open to new experiences and curious about the world.
– Extraversion: Describes a person who seeks excitement, who is active and very sociable.
Two analyses, one pair of conclusions
The study authors conducted two surveys involving more than 3,000 participants. The first analyzed data from people participating in the Baltimore Longitudinal Study of Aging (BLSA), an ongoing study of community-dwelling adults. Participants completed a 240-question questionnaire based on the Revised Personality Inventory test to identify their dominant traits among the Big 5. One year after the questionnaire, the absence or presence of amyloid plaques and tau proteins in their brains was assessed by PET scan. The second was a meta-analysis of 12 studies looking at associations between Alzheimer’s disease pathology and personality traits.
What the analyzes revealed
The BLSA-based study and meta-analysis came to the same conclusion: People with a high neuroticism score or a low conscientiousness score were more likely to have developed amyloid plaques and tau tangles. People with a high score on conscientiousness or low on neurosis were less likely to have them.
Research had previously looked at other personality traits, such as openness and extroversion, in relation to dementia, but neuroticism and conscientiousness have the strongest link, according to recent meta-analyses. The researchers also found that the association between these personality traits and pathology was strongest in people who were cognitively normal at the time of assessment in the BLSA study or the studies included in the meta-analysis. This suggests that personality type could be a risk factor before the emergence of amyloid and tau.
The reverse does not seem to be true. The researchers note, “These trends suggest that the associations are not emergent phenomena due to personality change with disease progression, as one would expect with reverse causation. »
A causal link?
Since this study is observational, it is difficult to say with certainty what the mechanisms are, and further research is needed.
One potential explanation is inflammation, which is associated with personality and the development of Alzheimer’s disease biomarkers. Lifestyle is another potential route. For example, highly conscientious people have been shown to have a healthier lifestyle: in terms of physical activity, smoking, sleep, depression, cognitive stimulation, etc. There is a strong body of research linking lifestyle, dementia risk, and biomarkers.
Certain aspects of neuroticism and conscientiousness could have a direct impact on the risk of dementia. Traits like neuroticism shape our emotional life, the way we deal with stress and deal with our feelings. Conscientiousness is defined by our level of grit, persistence, and planning attitude.
Personality associations with amyloid and tau: Results from the Baltimore Longitudinal Study of Aging and meta-analysis.