Neuroticism is a personality trait that indicates vulnerability to negative emotions including anger, anxiety, self‐consciousness, irritability, and emotional instability. It is sometimes defined as the tendency for quick arousal when stimulated and slow relaxation from arousal.
“Persons with elevated levels of neuroticism respond poorly to environmental stress, interpret ordinary situations as threatening, and can experience minor frustrations as hopelessly overwhelming.”
Neuroticism is a predictor of many mental and physical disorders and is considered “a psychological trait of profound public health significance”. For example, neuroticism is an important risk factor for depression, and higher neuroticism is associated with poor performance in cognitive tasks, accelerated cognitive decline, and increased pre-dementia syndromes.
A study by Janet Duchek et al., published last year, compared Alzheimer’s disease (AD) biomarkers – amyloid imaging, hippocampal volume, concentration of amyloid proteins (Aβ42), and tau proteins (both of which form plaques in the brain), and personality traits – neuroticism and conscientiousness, in people with early-stage AD vs. cognitively normal adults. The study had found that along with all four biomarkers, higher neuroticism and lower conscientiousness strongly discriminated cognitively normal controls from early-stage Alzheimer’s disease individuals. In other words, higher neuroticism and lower conscientiousness are independent behavioral markers of Alzheimer’s disease risk.
A recent study by Antonio Terracciano et al. examined whether neuroticism is associated with risk of incident Alzheimer’s disease (AD), and other dementias – vascular dementia (caused by brain damage from impaired blood flow to the brain), and frontotemporal dementia (caused by shrinkage of portions of frontal and temporal lobes). The study used self-reported neuroticism scores from participants (N = 401,422) of the UK Biobank, a biomedical database, and data related to the incidence of dementia – AD, VD, and FTD from linked electronic health records or death records of participants.
Researchers found that neuroticism was strongly associated with risk of all-cause dementia – AD, VD, and FTD (“one SD higher score on neuroticism was associated with ~20% higher risk of incident all-cause dementia”).
“Individuals in the top quartiles of neuroticism had about 70% higher risk of all-cause dementia compared to the individuals who scored in the lower quartile of neuroticism.”
Neuroticism was also associated individually with the risk of each – Alzheimer’s disease (70% higher risk) and Vascular Dementia (40% higher risk), but not Frontotemporal Dementia. The associations remained significant even after-effects of other risk factors – relevant demographics, education, socioeconomic status, cardiovascular conditions, blood biomarkers, and health-related behaviors were accounted for.
Read more about the study here.
