Influence of Personality on the Relationship Between Gray Matter Volume and Neuropsychiatric Symptoms in Multiple Sclerosis.
Research has revealed an association between personality traits and health outcomes, and in multiple sclerosis (MS), there are preliminary data showing a correlation between personality traits and brain volume. We examined the general hypothesis that personality influences the relationship between gray matter volume (GMV) and cognitive/neuropsychiatric MS features.Methods
Participants were 98 patients with MS who underwent magnetic resonance imaging and were tested with the Symbol Digit Modalities Test and the Neuropsychiatric Inventory, the latter providing measures of depression and euphoria that can be characteristic of MS, that is, cheerful indifference and disinhibition. Personality traits were assessed with the NEO Five Factor Inventory. We examined the correlation between personality traits and both GMV and symptoms, and then modeled mediation and moderation influences on the relationships between GMV and cognitive/neuropsychiatric features.ResultsLinear regression modeling revealed that GMV (r = 0.54, p < .001) and NEO Five Factor Inventory low conscientiousness (r = 0.36, p = .001) were associated with cognitive function, but no mediator or moderator effects were observed. However, conscientiousness mediated the relationship between GMV and symptoms of euphoria (p = .002). The moderator analysis revealed a significant influence of high neuroticism on the GMV-euphoria relationship (p = .029).Conclusions
Low conscientiousness and high neuroticism are associated with neuropsychiatric complications in MS, and each influences the relationship between GMV and euphoria. The findings suggest that patients with low conscientiousness are at higher risk for MS-associated cognitive dysfunction and neuropsychiatric symptoms, a conclusion that has implications for the emerging role of personality in clinical neuroscience.
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ABSTRACT: ObjectiveA nighttime dip in blood pressure is associated with decreased risk of cardiovascular morbidity and mortality. We examined whether personality traits predict nighttime dipping blood pressure.MethodsA community-based sample of 2848 adults from Sardinia (Italy) completed the Revised NEO Personality Inventory and 7 years later were examined with 24-hour ambulatory blood pressure monitoring. The primary analyses examined the associations of personality traits with continuous and categorical measures of mean arterial, systolic, and diastolic blood pressure nighttime dipping.ResultsAgreeableness and conscientiousness were associated with more nocturnal blood pressure dipping (β = .05 [p = .025] and β = .07 [p < .001], respectively) and lower systolic blood pressure at night (β = -.05 [p = .018] and β = -.03 [p = .072], respectively). Nondippers were particularly more impulsive (p = .009), less trusting (p = .004), and less self-disciplined (p = .001), but there was no significant association between nocturnal dipping blood pressure and trait anxiety (p = .78) or depression (p = .59). The associations were stronger when comparing extreme dippers (nighttime drop ≥20%) to reverse dippers (nighttime increase in blood pressure). Indeed, scoring 1 standard deviation higher on conscientiousness was associated with approximately 40% reduced risk of reverse dipping (odds ratio = 1.43, confidence interval = 1.08-1.91).Conclusions We found evidence that reduced nighttime blood pressure dipping is associated with antagonism and impulsivity-related traits but not with measures of emotional vulnerability. The strongest associations were found with conscientiousness, a trait that may have a broad impact on cardiovascular health.Psychosomatic Medicine 03/2014; DOI:10.1097/PSY.0000000000000035 · 4.09 Impact Factor