Nathalie Wan

Stress hormones and human memory function across the lifespan.

In this paper, we summarize the data obtained in our laboratory showing the effects of glucocorticoids on human cognitive function in older adults, young adults and children. We first present data obtained in the aged human population which showed that long-term exposure to high endogenous levels of glucocorticoids is associated with both memory impairments and a 14% smaller volume of the hippocampus. We then report on studies showing that in older adults with moderate levels of glucocorticoids, memory performance can be acutely modulated by pharmacological manipulations of glucocorticoids. In young adults, we present data obtained in our laboratory showing that cognitive processing sustained by the frontal lobes is also sensitive to acute increases of glucocorticoids. We also summarize studies showing that just as in older adults, memory performance in young adults can be acutely modulated by pharmacological manipulations of glucocorticoids. We then present a study in which we showed a differential involvement of adrenergic and glucocorticoid hormones for short- and long-term memory of neutral and emotional information. In the last section of the paper, we present data obtained in a population of young children and teenagers from low and high socioeconomic status (SES), where we showed that children from low SES present significantly higher levels of basal cortisol when compared to children from high SES. We then present new data obtained in this population showing that children and teenagers from low and high SES do not process the plausibility of positive and negative attributes in the same way. Children from low SES tended to process positive and negative attributes on a more negative note than children from high SES, and this type of processing was significantly related to basal cortisol at age 10, 12 and 14. Altogether, the results of these studies show that both bottom-up (effects of glucocorticoids on cognitive function), and top-down (effects of cognitive processing on glucocorticoid secretion) effects exist in the human population.

A transdisciplinary perspective of chronic stress in relation to psychopathology throughout life span development.

The allostatic load (AL) model represents an interdisciplinary approach to comprehensively conceptualize and quantify chronic stress in relation to pathologies throughout the life cycle. This article first reviews the AL model, followed by interactions among early adversity, genetics, environmental toxins, as well as distinctions among sex, gender, and sex hormones as integral antecedents of AL. We next explore perspectives on severe mental illness, dementia, and caregiving as unique human models of AL that merit future investigations in the field of developmental psychopathology. A complimenting transdisciplinary perspective is applied throughout, whereby we argue that the AL model goes beyond traditional stress-disease theories toward the advancement of person-centered research and practice that promote not only physical health but also mental health.

Diurnal cycle of salivary cortisol in older adult men and women with subjective complaints of memory deficits and/or depressive symptoms: Relation to cognitive functioning

In populations of young and older adults, it has been shown that individuals may be categorized into one of three diurnal subgroups when salivary cortisol levels are assessed over a 2-day period and compared for their consistency across days: a typical subgroup, a flat subgroup, and an inconsistent subgroup. Interestingly, recent studies have reported that the typical subgroup represents the majority of the young and older adult population, a finding that is difficult to reconcile with previous studies showing increased cortisol levels in older adults with depression or cognitive impairments. In order to assess whether a typical diurnal cortisol profile is representative across different subgroups of older adults, we assessed diurnal cortisol cycle representation in a sample of older adults with subjective complaints of depression and/or memory problems. Furthermore, given the robust relationship between cortisol and cognitive function, the present study examined the association between the three diurnal subgroups and cognitive performance. Forty-two older individuals were recruited on the basis of reporting subjective complaints of either memory problems and/or depressive mood. Participants were asked to sample their saliva over a 2-day period and were then asked to undergo a neuropsychological evaluation that taps into short-term memory, declarative memory and language. The results showed that 69% of the sample presented a Flat cycle of salivary cortisol over a 2-day period while 19% presented an inconsistent pattern and 12% presented a typical pattern. Participants in the flat subgroup were significantly impaired on letter verbal fluency. Furthermore, a relationship was found between diurnal cortisol subgroup representation and subjective complaint profile. These findings show that older adults with complaints of memory problems and/or depressive symptoms do not present the typical profile of the diurnal cortisol cycle, and they provide a preliminary view of how diurnal cortisol profile relates to cognitive function during human aging.

Facebook behaviors associated with diurnal cortisol in adolescents: Is befriending stressful?

Facebook(©) is changing the way people interact and socialize. Despite great interest in psychology and sociology, little is known about Facebook behaviors in relation to physiological markers of stress. Given that the brain undergoes important development during adolescence and that glucocorticoids--a major class of stress hormones-are known to modulate its development, it is important to study psychosocial factors that may influence secretion of stress hormones during adolescence. The goal of the present study was to explore the associations between Facebook behaviors (use frequency, network size, self-presentation and peer-interaction) and basal levels of cortisol among adolescent boys and girls. Eighty-eight adolescents (41 boys, 47 girls) aged between 12 and 17 (14.5 ± 1.8) were recruited. Participants provided four cortisol samples per day for two non-consecutive weekdays. Facebook behaviors were assessed in accordance with the existing literature. Well-validated measures of perceived stress, perceived social support, self-esteem, and depressive symptoms were also included. A hierarchical regression showed that after controlling for sex, age, time of awakening, perceived stress, and perceived social support, cortisol systemic output (area under the curve with respect to ground) was positively associated with the number of Facebook friends and negatively associated with Facebook peer-interaction. No associations were found among depressive symptoms, self-esteem, and cortisol. These results provide preliminary evidence that Facebook behaviors are associated with diurnal cortisol concentrations in adolescents.

The DeStress for Success Program: effects of a stress education program on cortisol levels and depressive symptomatology in adolescents making the transition to high school.

Various studies have shown that increased activity of the hypothalamic-pituitary-adrenal (HPA) axis can predict the onset of adolescent depressive symptomatology. We have previously shown that adolescents making the transition to high school present a significant increase in cortisol levels, the main product of HPA axis activation. In the present study, we evaluated whether a school-based education program developed according to the current state of knowledge on stress in psychoneuroendocrinology decreases cortisol levels and/or depressive symptoms in adolescents making the transition to high school. Participants were 504 Year 7 high school students from two private schools in the Montreal area. Adolescents of one school were exposed to the DeStress for Success Program while adolescents from the other school served as controls. Salivary cortisol levels and depressive symptomatology were measured before, immediately after as well as 3 months after exposure to the program. Measures of negative mood were obtained at baseline in order to determine whether adolescents starting high school with specific negative moods were differentially responsive to the program. The results show that only adolescents starting high school with high levels of anger responded to the intervention with a significant decrease in cortisol levels. Moreover, we found that adolescents who took part in the intervention and showed decreasing cortisol levels following the intervention (responders) were 2.45 times less at risk to suffer from clinical and subclinical depressive states three months post-intervention in comparison to adolescents who showed increasing cortisol levels following the intervention (nonresponders). This study provides the first evidence that a school-based program on stress is effective at decreasing cortisol levels and depressive symptomatology in adolescents making the transition to high school and it helps explain which adolescents are sensitive to the program and what are some of the characteristics of these individuals.

Depressive symptoms, cortisol, and cognition during human aging: The role of negative aging perceptions

Depressive symptoms and memory impairments are associated with heightened stress hormone levels during aging. A factor that is related to memory deficits during aging is internalized negative aging stereotypes; the idea people have about the process of aging. In this study, we assessed the associations between internalized negative aging stereotypes, depressive symptoms, subjective and objective memory assessments, and cortisol concentration among older adults. Forty older adults aged between 58 and 85 years (18 females and 22 males; mean age ± SD: 71.25 ± 8.80 years) were assessed in this study. Measures of internalized negative aging stereotypes, depressive symptoms, and both subjective and objective memory performance were assessed. Salivary samples were obtained for measurement of cortisol concentration. Stepwise linear regressions were executed in our main analyses. Internalized negative aging stereotypes were associated with increased depressive symptoms and subjective memory complaints. No significant differences were observed for objective memory performance, or cortisol concentration. Internalized negative aging stereotypes are associated with increased depressive symptomatology and subjective complaints of memory; however, they do not predict increased cortisol concentration nor objective memory performance during aging. These results indicate that the mechanism underlying the association between internalized negative aging stereotypes and cognitive impairments may not be related to dysregulations of cortisol secretion among older adults.

Early menarche predicts increased depressive symptoms and cortisol levels in Quebec girls ages 11 to 13.

Earlier age of menarche is believed to confer greater vulnerability to depressive symptoms via increased reactivity to stressors associated with adolescence. In this longitudinal study, we measured depressive symptoms and salivary cortisol levels in 198 boys and 142 girls between the ages of 11 and 13 tested four times during Grade 7 as they transitioned from elementary school to secondary school as per Quebecs education system. Results showed that girls who had already reached menarche before starting secondary school had significantly higher depressive symptoms and salivary cortisol levels across the school year in comparison to girls who had not reached menarche, who in turn presented higher depressive scores than boys. When we divided menarcheal girls as a function of menarcheal timing in subanalyses, we found that girls with early menarche presented consistently elevated depressive symptoms across the school year while girls with on-time menarche presented transient depressive symptoms but no differences in salivary cortisol levels. Collectively, these results show that early menarche is associated with high depressive symptoms and cortisol levels in adolescent girls. This developmental milestone may render girls more vulnerable to environmental stressors and therefore represents a critical period to intervene to promote mental health.

Sex and Gender Roles in Relation to Mental Health and Allostatic Load.

Objectives Beyond male/female binaries, gender roles represent masculine and feminine traits that we assimilate and enact throughout life span development. Bem proposed that “androgynous” individuals adeptly adapt to different contexts by alternating from a strong repertoire of both masculine and feminine gender roles. By contrast, “undifferentiated” individuals may not adapt as well to social norms because of weak self-endorsed masculinity and femininity. Methods Among 204 adults (mean [standard error] age = 40.4 [0.9] years; 70% women) working in a psychiatric hospital, we hypothesized that androgynous individuals would present better mental health and less physiological dysregulations known as allostatic load (AL) than undifferentiated individuals. AL was indexed using 20 biomarkers using the conventional “all-inclusive” formulation that ascribes cutoffs without regard for sex or an alternative “sex-specific” formulation with cutoffs tailored for each sex separately while controlling for sex hormones (testosterone, estradiol, progesterone). Well-validated questionnaires were used. Results Independent of sex, androgynous individuals experienced higher self-esteem and well-being and lower depressive symptoms than did undifferentiated individuals. Men manifested higher AL than did women using the all-inclusive AL index (p = .044, &eegr;2P = 0.025). By contrast, the sex-specific AL algorithm unmasked a sex by gender roles interaction for AL (p = .043, &eegr;2P = 0.048): with the highest AL levels in undifferentiated men. Analysis using a gender index based on seven gendered constructs revealed that a greater propensity toward feminine characteristics correlated only with elevated sex-specific AL (r = 0.163, p = .025). Conclusions Beyond providing psychobiological evidence for Bems theory, this study highlights how sex-specific AL formulations detect the effects of sociocultural gender.

Of chickens and men: reply to the letter to the editor of Gallagher JP et al., CRF is the 'egg and chicken', whereas ACTH and corticosteroids are only 'chickens' in response to stress

We thank Dr. Gallagher and co-workers for their letter underlying the importance of CRF in the stress response. We agree with the various facts and data summarized in the letter, and we note along with the authors that CRF and its related peptides have not received the attention that they deserve in relation to the stress response. However, what is important to underline here is that studying a human being is very different than studying a chicken, or a rodent. Although we understand that CRF may be the first marker to use in studies of the stress response, it is important to remind Dr. Gallagher and colleagues that CRF is extremely difficult to obtain in human populations, something that is not the case in animal studies. At this point, the only way to obtain reliable measures of CRF in humans is to perform a lumbar puncture for assessment of cerebrospinal fluid (CSF). This procedure is very painful for participants (Iannalfi et al., 2005), it raises clear ethical considerations in human populations (Botkin, 1989; Williams & Fost, 1992),