Resilience, Stress, and Cortisol Predict Cognitive Performance in Older Adults.

OBJECTIVE: to determine the relationship between stress, resilience, and cognitive performance in older people without dementia. METHOD: multiple linear regressions were performed using measures of cognitive performance as dependent variables, and measures of stress and resilience as predictors in a sample of 63 Spanish elderly people. RESULTS: participants reported low levels of stress during their lifetime. In addition to socio-demographic variables, greater stress was related to better delayed recall and worse letter-number sequencing and block design. Higher capillary cortisol was associated with lower flexibility on the Stroop task. Regarding protective factors, we found that greater psychological resilience was related to higher scores on the Addenbrooke's Cognitive Examination-III, letter-number sequencing, and verbal fluency. CONCLUSION: in older people with low stress, apart from age, gender, and education, psychological resilience is a significant predictor of global cognitive status, working memory, and fluency. Likewise, stress is related to verbal memory functioning, working memory, and visuoconstructive abilities. Capillary cortisol level predicts cognitive flexibility. These findings may help to identify risk and protective factors for cognitive decline in older people. Training-based programs to reduce stress and increase psychological resilience may play an important role in preventing cognitive decline.

Participation Predicts Cognitive Functioning in Older Adults Using the PART-O Transformed Scores Systems.

Participation has been shown to be a protective factor for cognition in older adults, but instruments to assess it are limited. The main objective was to determine the validity of two scoring systems (direct vs transformed) for the Participation Assessment with Recombined Tools-Objective (PART-O) by applying structural equation modeling to the relationship between the subscales and the cognitive functions, in a sample of 245 people over 60 years of age. The transformed scores model showed stronger relationships and larger explained variance in overall participation (55.4% vs 37.4%), especially in the Social Relations subscale (31.4% vs 14.6%). Participation was a direct predictor of cognitive functions in both models. Age and depression inversely influenced participation in the transformed scores model. The proposed score transformation for the PART-O provides a more appropriate measurement of the older adults' participation. Participation has a mediating role in the relationship between cognition and both age and depression.

Correction: Hair cortisol concentrations in a Spanish sample of healthy adults.

[This corrects the article DOI: 10.1371/journal.pone.0204807.].

Hair cortisol concentrations in a Spanish sample of healthy adults.

BACKGROUND: Hair cortisol concentration (HCC), as a novel promising method to retrospectively measure hypothalamic-pituitary-adrenal (HPA) axis activation, is being increasingly studied. We tested the relationships between HCC and a range of possible confounding variables in a Spanish sample of healthy adults and pregnant women. METHODS: The number of healthy adults who participated in the study was 529, being 270 males and 259 females, with a combined mean age of 37.88 years (SD = 15.66). Additionally, a separate sample of 62 pregnant women was also recruited with a mean age of 32.95 (SD = 3.67), and in the first trimester of pregnancy. Each participant was interviewed before the study to obtain sociodemographic and lifestyle variables, and a hair sample was taken from the posterior vertex of the head, cut as close to the scalp as possible. Assuming the average growth rate of head hair is 1 cm per month, a 3-cm segment was analysed, in order to measure the cortisol concentrations from a three-month period. For the pregnant women, hair samples for each trimester of pregnancy were analysed. RESULTS: The mean hair cortisol concentration was 127.91 (111.52) pg/mg for the general sample. The variables of age, education, employment status, use of hair dyes, use of oral contraceptives, and physical exercise had a significant relation to HCC. When adjusted for further variables, only education and physical exercise remained statistically significant. When including the use of oral contraceptives and only with respect to females, only physical exercise remains statistically significant. For the subsample of pregnant woman, the mean hair cortisol concentration was 334.51 (409.77) pg/mg for the first trimester, 302.18 (270.24) pg/mg for the second trimester, and 331.31 (295.46) pg/mg for the third trimester of pregnancy. None of the assessed confounding variables (age, body mass index, previous miscarriages, employment status, hair dyes, dependent children and physical exercise), except education level, was related to HCC. CONCLUSIONS: In this sample of healthy Spaniards, results suggested an association between HCC and physical exercise and educational level. In pregnant women, the prevalence of HCC was higher than in non-pregnant woman, and was related to educational level. This study emphasises the need to determine the relationship between HCC and confounders such as sociodemographic and lifestyle variables in the general population and specific groups formed by individuals such as pregnant women.