Health disparities in cognitive performance across the life span

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We reported earlier that symptoms of posttraumatic stress disorder were prevalent in urban neighborhoods and may affect cognitive performance in a similar fashion to the ways in which symptoms of depression affect performance. As a follow-on study, we reviewed the connection between intimate partner violence and specific depression outcomes in women. In a systematic review and meta-analysis, we summarized the extant literature and estimated the magnitude of the association between intimate partner violence and key depressive outcomes (elevated depressive symptoms, diagnosed major depressive disorder and postpartum depression). Studies suggested moderate or strong positive associations between intimate partner violence and depression. Our meta-analysis suggested two to three-fold increased risk of major depressive disorder and 1.5-2-fold increased risk of elevated depressive symptoms and postpartum depression among women exposed to intimate partner violence relative to non-exposed women. A sizable proportion (9%-28%) of major depressive disorder, elevated depressive symptoms, and postpartum depression can be attributed to lifetime exposure to intimate partner violence. Symptoms of depression are related to cognitive performance. Nutritional factors are also related to cognitive performance. We examined the relationship of elevated depressive symptoms with antioxidant status in cross-sectional data from the National Health and Nutrition Examination Surveys 2005-6 on US adults aged 20-85 years. Depressive symptoms were measured using the Patient Health Questionnaire with a score cut-off point of 10 to define 'elevated depressive symptoms'. Serum antioxidant status was measured by serum levels of carotenoids, retinol (free and retinyl esters), vitamin C and vitamin E. A higher total serum carotenoid level was associated with a lower likelihood of elevated depressive symptoms with a reduction in the odds by 37% overall with each standard deviation increase in exposure, and by 34% among women (p < 0.05). A dose-response relationship was observed when total serum carotenoids were expressed as quartiles (Q4 (1.62-10.1 mumol/l) v. Q1 (0.06-0.86 mumol/l): OR 0.41; 95 % CI 0.23, 0.76, P < 0.001; P for trend = 0.035), though no significant associations were found with the other antioxidant levels. Among carotenoids, beta-carotene (men and women combined) and lutein+zeaxanthins (women only, after control for dietary lutein+zeaxanthin intake and supplement use) had an independent inverse association with elevated depressive symptoms among US adults. None of the other serum antioxidants had a significant association with depressive symptoms, independently of total carotenoids and other covariates. In conclusion, total carotenoids (mainly beta-carotene and lutein+zeaxanthins) in serum were associated with reduced levels of depressive symptoms among community-dwelling US adults. Many studies have linked depression and obesity; few have more than two assessments of depressive symptoms and adiposity to address the potential bidirectional relationship between adiposity and depressive symptoms from young adulthood through old age. We tested whether baseline depressive symptoms are associated with changes in weight, whether baseline adiposity is associated with changes in depressive symptoms, and whether these associations vary by sex. Using hierarchical linear modeling (HLM) on 30 years of data, the trajectory of adiposity and depressive symptoms over adulthood was estimated from >10,000 observations (mean=4.5 assessments per participant) of body mass index (BMI; kg/m2), waist circumference and hip circumference and >10,000 observations (mean=4.5 assessments per participant) of the Center for Epidemiological Studies Depression Scale (CES-D). Baseline depressive symptoms and adiposity were then tested as predictors of the trajectory of adiposity and depressive symptoms respectively. Additional analyses tested for sex-specific associations. Sex moderated the association between depressive symptoms and weight gain such that women who experienced depressed affect had greater increases in BMI, waist and hip circumference across the adult lifespan, controlling for relevant demographic and behavioral covariates. Baseline adiposity was unrelated to the trajectory of depressive symptoms for both sexes. Women who experience symptoms of depression tend to gain more weight across adulthood than men who experience such symptoms. Whether an individual was normal weight or overweight was unrelated to changes in depressive symptoms across adulthood. A chronically elevated white blood cell (WBC) count is a risk factor for morbidity and mortality. We examined whether facets of impulsivity-impulsiveness, excitement-seeking, self-discipline, and deliberation-are associated with chronically elevated WBC counts. Community-dwelling participants (N = 5,652) from Sardinia, Italy, completed a standard personality questionnaire and provided blood samples concurrently and again 3 years later. Higher scores on impulsivity, in particular impulsiveness and excitement-seeking, were related to higher total WBC counts and higher lymphocyte counts at both time points. Impulsiveness was a predictor of chronic inflammation: for every standard deviation difference in this trait, there was an almost 25% higher risk of elevated WBC counts at both time points (OR = 1.23, 95% CI = 1.10-1.38). These associations were mediated, in part, by smoking and body mass index. The findings demonstrate that links between psychological processes and immunity are not limited to acute stressors; stable personality dispositions are associated with a chronic inflammatory state. Animal models and clinical studies suggest that brain-derived neurotrophic factor (BDNF) is involved in the pathophysiology of depression. We tested whether serum and plasma levels of BDNF are associated with trait neuroticism and its facets and with state measures of depressive symptoms in a community-based cohort (N = 2099). We measured serum and plasma BDNF concentrations and administered the Revised NEO Personality Inventory and the Center for Epidemiological Studies Depression Scale. Covariates included age, sex, cigarette smoking, obesity, and antidepressant use. Serum BDNF concentrations were inversely related to neuroticism (r = -0.074, p < .001), in particular the depression facet (r = -0.08, p < .001). Lower BDNF concentrations were also associated with severe depressive symptoms (odds ratio = 0.906; 95% confidence interval = 0.851-0.965). The association of serum BDNF with neuroticism was independent of depressive symptoms, indicating that serum BDNF might represent a biological correlate of neuroticism and not just of transient depressive states. Plasma BDNF was not associated with measures of depression. Our study suggests that lower serum BDNF is associated with both a dispositional vulnerability to depression and acute depressive states in the general population. In a community-dwelling sample, we examined whether personality traits prospectively predicted performance on a verbal fluency task. Open, extraverted, and emotionally stable participants had better verbal fluency. At the facet level, dispositionally happy and self-disciplined participants retrieved more words; those prone to anxiety and depression and those who were deliberative retrieved fewer words. Education moderated the association between conscientiousness and fluency such that participants with lower education performed better on the fluency task if they were also conscientious. Age was not a moderator at the domain level, indicating that the personality-fluency associations were consistent across the life span. A disposition toward emotional vulnerability and being less open, less happy, and undisciplined may be detrimental to cognitive performance.