Neuroticism and white matter hyperintensities

Association of neuroticism with incident dementia, neuroimaging outcomes, and cognitive function

INTRODUCTION

Higher neuroticism might be associated with dementia risk. Here we investigated modification by genetic predisposition to dementia, mediation by mental health and vascular conditions, neuroimaging outcomes, and cognitive function.

METHODS

Cox proportional-hazards models were used to assess the association between neuroticism score and incident dementia over up to 15 years in 1,74,164 participants. Cross-sectional analyses on dementia-related neuroimaging outcomes and cognitive function were conducted in 39,459 dementia-free participants.

RESULTS

Higher neuroticism was associated with an 11% higher risk of incident dementia, especially vascular dementia (15% higher risk), regardless of genetic predisposition to dementia. Mental and vascular conditions mediated the association of neuroticism with all-cause dementia and vascular dementia. Neuroticism was associated with higher cerebrovascular pathology, lower gray matter volume, and worse function across multiple cognitive domains.

DISCUSSION

Neuroticism could represent a risk factor for dementia, and vascular and mental health might drive these associations.

HIGHLIGHTS

Neuroticism was associated with an increased risk of incident all-cause dementia, particularly vascular dementia. Associations were not modified by genetic predisposition to dementia. Associations were largely mediated by mental and vascular conditions. Neuroticism was associated with increased cerebrovascular pathology and lower gray matter volume. Neuroticism was associated with worse function across multiple cognitive domains.

Feelings of tense and risk of incident dementia: A prospective study of 482,360 individuals

BACKGROUND

The relationship between feelings of tense, as a significant emotional distress, and dementia remains unclear. This study aimed to evaluate the association between feelings of tense and dementia.

METHODS

In UK Biobank, feelings of tense were measured with a standard item. The primary outcome was all cause of dementia (ACD) and its subtypes (Alzheimer's disease (AD), vascular dementia (VD), and other dementia). Cox regression models analyzed the association between feelings of tense and dementia risk, while linear regression examined the correlation with neuroimaging outcomes. The potential association and joint effects of AD and tenseness were evaluated based on the established genetic risk score (GRS).

RESULTS

During a median follow-up of 12.7 years among 482,360 participants, 7331 dementia cases were identified. Individuals with feelings of tense had a significantly increased risk of ACD (HR, 1.194; 95 % CI: 1.115-1.278), VD (HR, 1.164; 95 % CI: 1.007-1.346), and other dementia (HR, 1.181; 95 % CI: 1.081-1.289), but not AD in multi-adjusted models. This association persisted across various sensitivity analyses and exhibited some heterogeneity in subgroup analyses. Furthermore, feelings of tense are associated with total brain volume shrinkage, higher white matter hyperintensities, and decreased partial subcortical volume, particularly in the hippocampus. No interaction between tenseness and AD genetic susceptibility was observed (P for interaction =0.346).

LIMITATIONS

Our study only considered feelings of tense measured at a one-time point.

CONCLUSIONS

Our findings demonstrate a significant association between feeling of tense and elevated dementia risk, indicating that tenseness could serve as a modifiable psychological determinant for dementia.

Association of personality facets and cognition in the Lifelines population-based cohort study

BACKGROUND

Personality traits have been associated with cognitive functioning and risk of cognitive decline. Fewer studies have investigated how personality facets are associated with cognition in large cohorts with a prospective design.

METHODS

The association between eight personality facets and cognition (speed measures reflecting psychomotor speed and visual attention; hit rate measures reflecting visual learning and working memory) was analyzed in middle-aged adults from the Lifelines cohort (N = 79911; age 43 ± 11 years).

RESULTS

High hostility, high vulnerability, low excitement seeking, and low competence were associated with worse cognitive performance on all tasks. Impulsivity-related facets had weak and differential associations, with self-discipline negatively associated with accuracy and deliberation negatively associated with speed. These associations remained largely unchanged when accounting for lifestyle factors (smoking, alcohol consumption, physical activity). The associations with cognition were stronger in older people for impulsiveness, deliberation, and hostility, while stronger in younger people for excitement seeking, self-discipline, and vulnerability.

CONCLUSION

In a large population-based sample with a broad age range, the associations of personality facets with cognitive functioning had small effect sizes, were independent of lifestyle factors, and varied with age and among facets within the same personality domain. These findings highlight the importance of developmental stages and facet-level research in personality-cognition associations.