Adult Stress Research Articles

Transcriptomic and functional genetic evidence for distinct ecophysiological responses across complex life cycle stages.

Organisms with complex life cycles demonstrate a remarkable ability to change their phenotypes across development, presumably as an evolutionary adaptation to developmentally variable environments. Developmental variation in environmentally sensitive performance, and thermal sensitivity in particular, has been well documented in holometabolous insects. For example, thermal performance in adults and juvenile stages exhibit little genetic correlation (genetic decoupling) and can evolve independently, resulting in divergent thermal responses. Yet, we understand very little about how this genetic decoupling occurs. We tested the hypothesis that genetic decoupling of thermal physiology is driven by fundamental differences in physiology between life stages, despite a potentially conserved cellular stress response. We used RNAseq to compare transcript expression in response to a cold stressor in Drosophila melanogaster larvae and adults and used RNA interference (RNAi) to test whether knocking down nine target genes differentially affected larval and adult cold tolerance. Transcriptomic responses of whole larvae and adults during and following exposure to -5°C were largely unique both in identity of responding transcripts and in temporal dynamics. Further, we analyzed the tissue-specificity of differentially expressed transcripts from FlyAtlas 2 data, and concluded that stage-specific differences in transcription were not simply driven by differences in tissue composition. In addition, RNAi of target genes resulted in largely stage-specific and sometimes sex-specific effects on cold tolerance. The combined evidence suggests that thermal physiology is largely stage-specific at the level of gene expression, and thus natural selection may be acting on different loci during the independent thermal adaptation of different life stages.

Frequent Low-Dose Δ9-Tetrahydrocannabinol in Adolescence Disrupts Microglia Homeostasis and Disables Responses to Microbial Infection and Social Stress in Young Adulthood

BackgroundDuring adolescence, microglia are actively involved in neocortical maturation while concomitantly undergoing profound phenotypic changes. Because the teenage years are also a time of experimentation with cannabis, we evaluated whether adolescent exposure to the drug’s psychotropic constituent, Δ9-tetrahydrocannabinol (THC), might persistently alter microglia function. MethodsWe administered THC (5 mg/kg, intraperitoneal) once daily to male and female mice from postnatal day (PND) 30 to PND44 and examined the transcriptome of purified microglia in adult animals (PND70 and PND120) under baseline conditions or following either of two interventions known to recruit microglia: lipopolysaccharide injection and repeated social defeat. We used high-dimensional mass cytometry by time-of-flight to map brain immune cell populations after lipopolysaccharide challenge. ResultsAdolescent THC exposure produced in mice of both sexes a state of microglial dyshomeostasis that persisted until young adulthood (PND70) but receded with further aging (PND120). Key features of this state included broad alterations in genes involved in microglia homeostasis and innate immunity along with marked impairments in the responses to lipopolysaccharide- and repeated social defeat–induced psychosocial stress. The endocannabinoid system was also dysfunctional. The effects of THC were prevented by coadministration of either a global CB1 receptor inverse agonist or a peripheral CB1 neutral antagonist and were not replicated when THC was administered in young adulthood (PND70–84). ConclusionsDaily low-intensity CB1 receptor activation by THC during adolescence may disable critical functions served by microglia until young adulthood with potentially wide-ranging consequences for brain and mental health.

A Potential Link Between Negative Affective Responsivity to Daily Stress and Blood Pressure Reactivity to Acute Stress in College‐Aged Adults

Daily stress, defined as the routine challenges of day‐to‐day living and the unexpected small hassles that disrupt everyday life, is predictive of future cardiovascular disease (CVD)‐related health outcomes; however, the underlying mechanisms remain unclear. Given that heightened blood pressure (BP) reactivity to stress is also purported to increase future CVD risk, we examined a potential link between daily stress and acute stress‐induced increases in BP. We hypothesized that increased frequency of daily stressor exposures and greater negative emotional responsiveness to daily stress (i.e., negative affective responsivity) would be positively related to increased BP reactivity to acute stressors in the laboratory setting. Thirty adults (23±5 yrs; 21 female) completed the Daily Inventory of Stressful Events (DISE) interview every day for 8 consecutive days to quantify objective (e.g., frequency) and subjective appraisal characteristics (e.g., emotions) of naturally occurring daily stressors (e.g., stressful event at home/work). On DISE Day 8, mean arterial pressure (MAP; finger photoplethysmography) was measured during two distinct laboratory‐based acute stress stimuli: the cold pressor test (CPT; generalized sympathoexcitatory stimulus) and the Stroop Color Word Test (SCWT; cognitive stress stimulus). Daily stress exposure was calculated as the total number of stressors across the 8‐day protocol, and negative affective responsivity was calculated as the magnitude of the increase in negative affect on stressor exposure days (at least 1 stressor reported) compared to negative affect on non‐stressor exposure days (no stressors reported). BP reactivity was quantified as the peak acute stress‐induced increase in MAP to the CPT and SCWT. Participants experienced a total of 3±3 stressors (range: 0‐9) over the 8‐day interview timeframe. Negative affect was greater on stressor exposure days (0.68±0.50 a.u.) compared to non‐exposure days (0.37±0.36 a.u.; p<0.01). Both the CPT (∆21±7 mmHg) and the SCWT (∆9±6 mmHg) elicited increases in MAP (both p<0.05). The total number of stressors was not related to the peak increase in MAP during either the CPT (slope=‐0.10; r=0.04; p=0.85) or the SCWT (slope=‐0.43; r=19; p=0.31). Negative affective responsivity was positively related to the peak increase in MAP during the CPT (slope=12.41; r=0.45; p=0.03) but not the SCWT (slope=3.00; r=0.14, p=0.50). These preliminary data demonstrate that daily stressor exposure by itself is not related to BP reactivity to laboratory stressors in college‐aged adults. However, greater negative affective responsivity is associated with greater acute stress‐induced increases in BP during the CPT, but not the SCWT, perhaps suggesting that the link between daily stress processes and BP reactivity may be dependent on the stress‐responsive neurocircuitry being activated.

The effects of stress across the lifespan on the brain, cognition and mental health: A UK biobank study

Repeated overstimulation of the stress response system, caused by exposure to prolonged highly stressful experiences, is thought to affect brain structure, cognitive ability, and mental health. We tested the effects of highly stressful experiences during childhood and adulthood using data from the UK Biobank, a large-scale national health and biomedical study with over 500,000 participants. To do this, we defined four groups with high or low levels of childhood and/or adulthood stress. We then used T1-and diffusion-weighted MRI data to assess the macrostructure of grey matter and microstructure of white matter within limbic brain regions, commonly associated with the stress response. We also compared executive function and working memory between these groups. Our findings suggest that in females, higher levels of Childhood stress were associated with reduced connectivity within the posterior thalamic radiation and cingulum of the hippocampus. In males however, higher levels of Adulthood stress is associated with similar changes in brain microstructure in the posterior thalamic radiation and cingulum of the hippocampus. High stress in Childhood and Adulthood was associated with decreases in executive function and working memory in both males and females. Stress across the lifespan was also positively associated with the number of diagnosed mental health problems, with a stronger effect in females than in males. Finally, our findings also suggest that cognitive and mental health outcomes due to stress may be mediated by the sex specific stress related changes in brain microstructure. Together our findings demonstrate clear links between stress at distinct phases of the lifespan, changes in measures of brain microstructure, impairments in cognitive abilities and negative mental health outcomes.

Mechanisms of Cardiometabolic Health Outcomes and Disparities: What Characteristics of Chronic Stressors are Linked to HPA-Axis Dysregulation?

Objectives: Chronic stressors are associated with cardiometabolic health conditions and disparities. Mechanisms linking stressors and health remain poorly understood. Methods: Two cohort studies (Cardiac Rehabilitation And The Experience [CREATE] and Tracking Risk Identification for Adult Diabetes [TRIAD]) with harmonized variables were used to examine relationships between six types of chronic stressors in adulthood and Hypothalamic-Pituitary-Adrenal (HPA) axis dysregulation, as indicated by blunted diurnal cortisol slopes, which are stress-sensitive biomarkers implicated in cardiometabolic health (merged N = 213, mean age 61, 18% Black). A secondary aim was to explore whether these chronic stressors accounted for Black-White disparities in HPA axis regulation. Results: Some chronic stressors were linked to HPA axis dysregulation, with recent stressors most salient (b = 0.00353, SE = 0.00133, p = .008). Black-White disparities in HPA axis regulation persisted after controlling for racial differences in chronic stressors, which reduced the disparity 11.46%. Discussion: Chronic stressors in adulthood may increase risk for HPA axis dysregulation and associated cardiometabolic health outcomes but may not be a key factor in racial disparities.

The cannabinoid receptor-1 gene interacts with stressful life events to increase the risk for problematic alcohol use

Problematic alcohol use is a major contributor to the global burden of death and disabilities, and it represents a public health concern that has grown substantially following the COVID-19 pandemic. The available treatment options remain limited and to develop better pharmacotherapies for alcohol misuse we need to identify suitable biological targets. Previous research has implicated the brain’s endocannabinoid system (ECS) in psychiatric and stress-related outcomes, including substance use and habituation to repeated stress. Moreover, genetic variants in the cannabinoid-1 receptor gene (CNR1; CB1R) have been associated with personality traits, which are in turn predictors of substance use disorders. To date, however, no human genome-wide association study has provided evidence for an involvement of the ECS in substance use outcomes. One reason for this ECS-related “missing heritability” may be unexamined gene-environment interactions. To explore this possibility, we conducted cross-sectional analyses using DNA samples and stress-exposure data from a longitudinal Swedish population-based study (N = 2,915). Specifically, we genotyped rs2023239, a functional C/T single nucleotide polymorphism in CNR1, previously reported to be associated with CNR1 binding in the brain, subjective reward following alcohol intake, and alcohol cue-elicited brain activation. Our two outcomes of interest were (i) problematic alcohol use based on the Alcohol Use Disorders Identification Test (AUDIT), and (ii) personality trait scores based on the Five Factor Model. We found no baseline association between rs2023239 and problematic alcohol use or personality traits. However, there was a clear trend for interaction between rs2023239’s risk allele (C) and stressful life events (SLEs) in both childhood and adulthood, which predicted problematic alcohol use. Although not significant, there was also some indication that the risk allele interacted with child SLEs to increase scores on neuroticism. Our study supports the notion that the ECS can affect alcohol intake behaviors by interacting with life adversities and is—to the best of our knowledge—the first to focus on the interaction between CNR1 and stressors in both childhood and adulthood in humans. Further studies are warranted to confirm these findings.

The mediating role of attachment and mentalising in the relationship between childhood maltreatment, self-harm and suicidality

BackgroundAlthough the relationship between childhood maltreatment, self-harm and suicidality is well-established, less is known about the mediating mechanisms explaining it. Based on a developmental mentalisation-based theoretical framework, childhood adversity compromises mentalising ability and attachment security, which in turn increase vulnerability to later stressors in adulthood. ObjectiveThis study aimed to investigate the role of attachment and mentalising as potential mechanisms in the relationship between childhood maltreatment, self-harm and suicidality. Participants and settingWe recruited 907 adults from clinical and community settings in Greater London. MethodsThe study design was cross-sectional. Participants completed self-report questionnaires on retrospectively rated childhood trauma, and current attachment to the romantic partner, mentalising, self-harm, suicidal ideation and attempt. We used structural equation modelling to examine the data and conceptualized childhood maltreatment as a general factor in a confirmatory bifactor model. ResultsThe results showed that childhood maltreatment was both directly associated with self-harm and suicidality and indirectly via the pathways of attachment and mentalising. ConclusionsThese findings indicate that insecure attachment and impaired mentalising partially explain the association between childhood maltreatment, self-harm and suicidality. Clinically, they provide support for the potential of mentalisation-based therapy or other psychosocial interventions that aim to mitigate the risk of self-harm and suicidality among individuals who have experienced childhood maltreatment via increasing understanding of self and other mental states.

The assessment of childhood maltreatment and its associations with affective symptoms in adulthood: Results of the German National Cohort (NAKO)

Objectives Childhood maltreatment affects 20–30% of the German population and is an important risk factor for physical and mental diseases in adult life. This study reports first results of the distribution of childhood maltreatment in the population-based mega cohort German National Cohort (NAKO) and estimates associations with affective symptoms in adulthood. Methods The Childhood Trauma Screener (CTS), a short version of the Childhood Trauma Questionnaire, was used in 83,995 adults (age: 20–72 years; 47.3% men) of NAKO. The five-item CTS assesses the severity of three types of childhood abuse and two types of childhood neglect. Results Overall, 21,131 participants (27.5%) reported at least one type of childhood maltreatment; 14,017 participants (18.3%) reported exactly one type and 250 participants (0.3%) reported all five types of childhood maltreatment. Small differences regarding age (mean absolute deviation around the mean (MAD)=0.47), sex (MAD = 0.07) and education (MAD = 0.82) were observed. The severity of childhood maltreatment was associated with more severe symptoms of depression (β = 0.23), anxiety (β = 0.21) and perceived stress (β = 0.23) in adulthood, validated particularly for emotional abuse and emotional neglect. Conclusions The distribution of childhood maltreatment in NAKO is similar to previous reports. Additionally, our results suggest differential associations with psychopathological symptoms for the five types of childhood maltreatment.

COVID-related distress, mental health, and substance use in adolescents and young adults.

BackgroundThis study examined the impact of COVID‐related disruptions on mental health and substance use in young people residing in a state with an initially lower COVID burden and earlier reopening of in‐person learning than other states.MethodsData come from Waves 3 (Fall 2019) and 4 (Fall 2020) of the Policy and Communication Evaluation (PACE) Vermont, an online cohort study of adolescents (ages 12–17) and young adults (ages 18–25). Participants in Wave 4 (212 adolescents; 662 young adults) completed items on COVID‐related stressors, the impact of the pandemic on their substance use, brief mental health scales, and past 30‐day substance use. Analyses examined correlational and longitudinal relationships between COVID‐related stressors, mental health symptoms, and substance use.ResultsMore than 60% of participants noted negative effects of the pandemic on their physical, emotional, and social well‐being, with greater impacts of COVID‐related stressors in young adults than adolescents. There were significant increases in depressive (OR 1.31, 95% CI 1.03, 1.66) and anxiety symptoms (OR 1.34; 95% CI 1.10, 1.64) in young adults between Fall 2019 and Fall 2020. Higher overall COVID Impact scores were associated with higher odds of depressive and anxiety symptoms, as well as past 30‐day electronic vapor product use, in adjusted cross‐sectional and longitudinal models.ConclusionsRobust associations between COVID‐related distress, mental health, and substance use outcomes in young people signal the opportunity to increase evidence‐based interventions while adding novel approaches to minimize longer‐term harms of the pandemic on mental health in adolescents and young adults.

Dental cementum virtual histology of Neanderthal teeth from Krapina (Croatia, 130-120 kyr): an informed estimate of age, sex and adult stressors.

The evolution of modern human reproductive scheduling is an aspect of our life history that remains vastly uncomprehended. The present work aims to address this gap by validating a non-destructive cutting-edge methodology to infer adult life-history events on modern teeth with known life history and then applying it to fossil specimens. We use phase-contrast synchrotron X-ray microtomography to visualize the dental cementum of 21 specimens: nine contemporary humans; 10 Neanderthals from Krapina (Croatia, 130-120 kyr); one Neolithic Homo sapiens from Ajmana (Serbia); and one Mesolithic H. sapiens from Vlasac (Serbia). We were able to correctly detect and time (root mean square error = 2.1 years; R2 = 0.98) all reproductive (menarche, parturition, menopause) and other physiologically impactful events in the modern sample. Nonetheless, we could not distinguish between the causes of the events detected. For the fossil specimens, we estimated age at death and age at occurrence of biologically significant events. Finally, we performed an exploratory analysis regarding possible sexual dimorphism in dental cementum microstructure, which allowed us to correctly infer the sex of the Neolithic specimen, for which the true value was known via DNA analysis.

Early maternal separation alters the activation of stress-responsive brain areas in adulthood

The expression of c-Fos protein has been extensively used as a marker of neuronal activation in response to stressful stimuli. Early maternal separation (MS) is a model of early life adversity that affects the responsiveness of the brain areas to stressors. Thus, this study examined the impact of early MS on activating stress-responsive areas in the brain of adult rats in response to physical (ether) or psychological (restraint) stressors. Male pups were divided for the MS or non-handled (NH) groups. The MS was carried out daily between the 2nd and 14th day of postnatal life and consisted in removing the dams from the cage for 180 min. The rats were then subjected to experimental protocols of restraint or ether exposure at 10–12 weeks old. The rats were anesthetized 90 min after exposure to the stressors, and their brains were prepared for immunohistochemical analysis of c-Fos immunoreactive (c-Fos-ir) neurons in the hypothalamic paraventricular nucleus (PVN), supraoptic nucleus (SON), medial preoptic area (MPA), medial amygdaloid nucleus (MeA), locus coeruleus (LC), and nucleus of the solitary tract (NST). The MS-group presented 86%, 125%, 73%, 56%, and 137% higher c-Fos-ir neurons in the LC, PVN, SON, MPA, and MeA, respectively, compared to NH-group in response to the restraint stressor. In addition, the MS-group presented 180%, 137%, 170%, and 138% higher c-Fos-ir neurons for the ether exposure in the LC, PVN, MPA, and MeA, respectively. Our results show a greater increase in neuronal activation in the MS group, indicating that early life adversity can induce reprogramming in the brain response to stress in adulthood.

The Impact of Child and Adult Stressors on Multiple Sclerosis Biopsychosocial Disease Features

The Impact of Child and Adult Stressors on Multiple Sclerosis Biopsychosocial Disease Features

The influence of early-life and adulthood stressors on brain neuropeptide-S system

Central administered neuropeptide-S (NPS) was shown to reduce stress response in rodents. This study aimed to investigate the alterations in NPS system upon chronic exposure to early-life and adulthood stressors. Newborn pups underwent maternal separation (MS) from postnatal day 1 to 14 comprised of daily 3-h separations. In the adulthood, 90-min of restraint stress was loaded to males as an acute stress (AS) model. For chronic homotypic stress (CHS), same stressor was applied for 5 consecutive days. The changes in the expression and the release of NPS were monitored by immunohistochemistry and microdialysis, respectively. Throughout the CHS, heart rate variability (HRV) was analyzed on a daily basis. The immunoreactivity for NPS receptor (NPSR) was detected in basolateral amygdala (BLA) and hypothalamic paraventricular nucleus (PVN) by immunofluorescence staining. The NPS expression in the brainstem was increased upon AS which was more prominent following CHS, whereas these responses were found to be blunted in MS counterparts. Similar to histological data, the stress-induced release of NPS in BLA was attenuated in MS rats. CHS-induced elevations in sympatho-vagal balance were alleviated in control rats; which was not observed in MS rats. The expression of NPSR in BLA and PVN was down-regulated in MS rats. The brain NPS/NPSR system appears to be susceptible to the early-life stressors and the subsequent chronic stress exposure in adulthood which results in altered autonomic outflow.

Single-Cell Transcriptional Changes in Hypothalamic Corticotropin-Releasing Factor–Expressing Neurons After Early-Life Adversity Inform Enduring Alterations in Vulnerabilities to Stress

BackgroundMental health and vulnerabilities to neuropsychiatric disorders involve the interplay of genes and environment, particularly during sensitive developmental periods. Early-life adversity (ELA) and stress promote vulnerabilities to stress-related affective disorders, yet it is unknown how transient ELA dictates lifelong neuroendocrine and behavioral reactions to stress. The population of hypothalamic corticotropin-releasing factor (CRF)–expressing neurons that regulate stress responses is a promising candidate to mediate the long-lasting influences of ELA on stress-related behavioral and hormonal responses via enduring transcriptional and epigenetic mechanisms. MethodsCapitalizing on a well-characterized model of ELA, we examined ELA-induced changes in gene expression profiles of CRF-expressing neurons in the hypothalamic paraventricular nucleus of developing male mice. We used single-cell RNA sequencing on isolated CRF-expressing neurons. We determined the enduring functional consequences of transcriptional changes on stress reactivity in adult ELA mice, including hormonal responses to acute stress, adrenal weights as a measure of chronic stress, and behaviors in the looming shadow threat task. ResultsSingle-cell transcriptomics identified distinct and novel CRF-expressing neuronal populations, characterized by both their gene expression repertoire and their neurotransmitter profiles. ELA-provoked expression changes were selective to specific subpopulations and affected genes involved in neuronal differentiation, synapse formation, energy metabolism, and cellular responses to stress and injury. Importantly, these expression changes were impactful, apparent from adrenal hypertrophy and augmented behavioral responses to stress in adulthood. ConclusionsWe uncover a novel repertoire of stress-regulating CRF cell types differentially affected by ELA and resulting in augmented stress vulnerability, with relevance to the origins of stress-related affective disorders.

Perceived Stress and Life Stressors in Adults With and Without Fibromyalgia

Population aging will inevitably bring an increasing burden of poor cognitive function. The risk factors for cognitive decline have been widely studied. Even though environmental hazards have the greatest adverse impacts on older adults and the existing evidence has shown that green space, air pollution, and weather have an impact on cognitive function, most of the studies were conducted in developed countries and limited to cross-sectional analyses. China has the largest aging population in the world so the research evidence from it can offer an insight to the study in other developing countries facing similar issues and inform future public health policy and disease control. Using the data from a nationally representative sample of adults aged 45 years and older from the three waves of China Health and Retirement Longitudinal Study (CHARLS 2011-2015) and China City Statistical Yearbook, this study estimated multilevel growth curve models for the effects of green space coverage, air pollution, and weather conditions on cognitive function and cognitive decline. It showed that after controlling for sociodemographic characteristics, built area green coverage rate was positively associated with cognition score at baseline, and higher annual minimum temperature was associated with faster decline in cognitive function. These effects did not substantially change after weekly total hours of physical activities and levels of social engagement were added and the interaction effects were examined between environmental conditions with them, respectively. More research on the mechanisms of the effects of environmental factors on cognition is needed such as the subgroup analyses.

Life Course Stressors and Functional Limitations in Later Life Among White, Black, and Hispanic Adults

Although striking racial and ethnic disparities in health are manifest during later life, they may be rooted in early-life exposures. Drawing from cumulative inequality theory, we investigate whether experiencing life course stressors increases the risk of later-life functional limitations and whether this relationship differs by race and ethnicity. This study utilizes longitudinal data from the Health and Retirement Study to test whether six indicators of child stressors and eleven indicators of adult stressors predict trajectories of the onset and severity of functional limitations in later life among a diverse sample of adults. We find that child and adult stressors are associated with earlier onset and greater severity of functional limitations during later life. Mediation analyses reveal the indirect influence of child stressors via adult stressors on onset and severity of functional limitations; however, the indirect effects are slightly stronger for Black and Hispanic adults than their White counterparts (i.e., moderated mediation). In sum, child stressors, in and of themselves, do not increase functional limitations among Black and Hispanic people but are associated with greater adult stress exposure, leading to more functional limitations in later life. Disparities in functional limitations are also partly due to lower education and less wealth among Black and Hispanic adults.

Effects of Loneliness and Stress Management on Perceived Stress in Older Adults

According to socioemotional selectivity theory, older adults are more selective and tend to shrink their social network to their closest ties. However, a heightened need to belong, which is characterized by a stronger desire for acceptance and motivation to affiliation, may alter this common pattern. We know little about how the need to belong shapes social network structure, especially in late life. This study investigated the associations between the need to belong, size of social network, and engagement with social ties among older adults. Participants (N = 314) aged over 65 years from the Daily Experiences and Well-being Study completed a baseline interview regarding their close ties (i.e., social convoy members), and weak ties, as well as a self-report measure of need to belong. They completed ecological momentary assessment (EMA) surveys reporting their social encounters every 3 hours over 5 to 6 days. Need to belong was unrelated to the number of close ties. In contrast, participants with a higher need to belong reported more less close (but still important) ties and weak ties than those with a lower need to belong, but spent a similar amount of time (i.e., proportion of EMA involving social encounters) with either their close ties or weak ties. These results suggest that the need to belong may motivate older adults to go beyond their closest ties to weaker ties, and highlight the discrepancies between the sense of being connected to social partners and the actual engagement with them in this process.

Proactive Coping and Mindfulness are Associated with Less Stress in Older Adults

We examined the consequences of both chronic and life-event stressors for older adults, as well as antecedent strategies, such as proactive coping and mindfulness, that may mitigate stress. Given the potential negative outcomes associated with stress in older adulthood, exploring strategies to reduce or mitigate the negative impact of stress may be useful in promoting well-being in adulthood. Proactive coping involves an accumulation of resources that leads to reduced or avoided stressors in the future (Aspinwall & Taylor, 1997). Mindfulness calls an individual’s attention to the present moment, or may be characterized as an open, accepting attitude (Brown & Ryan, 2003). Using data from the Mindfulness and Anticipatory Coping Everyday study (English et al., 2019; Neupert & Bellingtier, 2017), 296 older adults in the United States, aged 60-90 years (M = 64.67, SD = 4.36), participated in relevant online survey measures. Results from multiple regression analyses suggested that people high in both chronic stress and life event stress had worse health, and that people high in proactive coping and mindfulness reported less stress. Study results underscore the impact of stress on health outcomes, and provide support for the use of antecedent strategies to address negative impacts of stress.

Dietary Milk Phospholipids Attenuate Chronic Stress-Induced Changes in Behavior and Endocrine Responses across the Lifespan.

Increasing scientific evidence is validating the use of dietary strategies to support and improve brain health throughout the lifespan, with tailored nutritional interventions catering for specific life stages. Dietary phospholipid supplementations in early life and adulthood are shown to alleviate some of the behavioral consequences associated with chronic stress. This study aims to explore the protective effects of a tailored phospholipid-enriched buttermilk on behavioral and endocrine responses induced by chronic psychosocial stress in adulthood, and to compare these effects according to the life stage at which the supplementation is started. A novel developed phospholipid-enriched dairy product is assessed for its effects on social, anxiety- and depressive-like behaviors, as well as the stress response and cognitive performance following chronic psychosocial stress in C57BL/6J mice, with supplementation beginning in adulthood or early life. Milk phospholipid supplementation from birth protects adult mice against chronic stress-induced changes in endocrine response to a subsequent acute stressor and reduces innate anxiety-like behavior in non-stressed animals. When starting in adulthood, the dietary intervention reverses the anxiety-like phenotype caused by chronic stress exposure. Dairy-derived phospholipids exert differential protective effects against chronic psychosocial stress depending on the targeted life stage and duration of the dietary supplementation.

Sex-Specific Behavioral Response to Early Adolescent Stress in the Genetically More Stress-Reactive Wistar Kyoto More Immobile, and Its Nearly Isogenic Wistar Kyoto Less Immobile Control Strain.

Genetic predisposition and environmental stress are known etiologies of stress-related psychiatric disorders. Environmental stress during adolescence is assumed to be particularly detrimental for adult affective behaviors. To investigate how genetic stress-reactivity differences modify the effects of stress during adolescence on adult affective behaviors we employed two inbred strains with differing stress reactivity. The Wistar Kyoto More Immobile (WMI) rat strain show increased stress-reactivity and despair-like behaviors as well as passive coping compared to the nearly isogenic control strain, the Wistar Kyoto Less Immobile (WLI). Males and females of these strains were exposed to contextual fear conditioning (CFC) during early adolescence (EA), between 32 and 34 postnatal days (PND), and were tested for the consequences of this mild EA stress in adulthood. Early adolescent stress significantly decreased anxiety-like behavior, measured in the open field test (OFT) and increased social interaction and recognition in adult males of both strains compared to controls. In contrast, no significant effects of EA stress were observed in adult females in these behaviors. Both males and females of the genetically less stress-reactive WLI strain showed significantly increased immobility in the forced swim test (FST) after EA stress compared to controls. In contrast, immobility was significantly attenuated by EA stress in adult WMI females compared to controls. Transcriptomic changes of the glucocorticoid receptor (Nr3c1, GR) and the brain-derived neurotrophic factor (Bdnf) illuminate primarily strain and stress-dependent changes, respectively, in the prefrontal cortex and hippocampus of adults. These results suggest that contrary to expectations, limited adolescent stress is beneficial to males thru decreasing anxiety and enhancing social behaviors, and to the stress more-reactive WMI females by way of decreasing passive coping.