Lifetime Stress Research Articles

Longitudinal Examination of an Ethnic Paradox of Stress and Mental Health in Older Black and Latinx Adults

ABSTRACT Objectives To explain the ethnic paradox of mental health in aging, we evaluated whether Black and Latinx older adults experience (1) fewer depressive symptoms (DepSx), but more physical problems, and (2) greater psychological resilience as a result of life stressors than White older adults. Methods DepSx, physical health, and recent stress were obtained biennially from 25,893 older adults (77% White, 15% Black, 9% Latinx) in the U.S. Health and Retirement Study, across 16 years. Psychological resilience, lifetime stress, and discrimination experiences were available for 13,655 individuals. We conducted mixed-effects and linear regression analyses. Results For Blacks and Latinxs, experiencing more-than-usual stress events was associated with less increase in DepSx compared to Whites, although on average Blacks and Latinxs experience more DepSx. Black adults showed worse physical health than White adults and weaker effects of stress on psychological resilience despite experiencing more stress of all types. Findings were mixed for Latinxs. Conclusions Studying effects of time-varying stress on changes in health and multiple stressors on psychological resilience by race/ethnicity elucidates mechanisms for later-age health disparities. Clinical Implications Cross-sectional evaluations of stress and psychological health in a clinical setting may provide incomplete appraisals of health risks for Black and Latinx older Americans.

Special Report: Stress and Distress During Pregnancy—How to Protect Both Mother and Child

Special Report: Stress and Distress During Pregnancy—How to Protect Both Mother and Child

Abstract WP219: Lifetime Stress, Acute Stress, And Outcomes After Stroke -- A Longitudinal Study Of Stroke Survivors

Background: Stroke is a sudden-onset, unexpected life event over which individuals have little control. These features can make the experience of having a stroke extremely stressful, which may potentiate its debilitating effects. Yet the role of lifetime stress/trauma exposure (LSE) and post-stroke acute stress (AS) have received limited attention in research seeking to identify factors influencing stroke-related disability. Hypothesis: Higher lifetime trauma and AS symptoms are associated with poorer post-stroke modified Rankin (mRS) and Fugl-Meyer scores. Method: Multi-site national study of patients admitted for a new stroke. Interviews were conducted at 2-10 days (N=763) & 3 months (N=513) post-stroke. Assessments included admission Acute Stress Disorder Interview, day-90 mRS, day-90 upper extremity motor Fugl-Meyer scale (affected side), and LSE. Structural Equation Modeling examined relationships among LSE, AS, and outcomes, controlling for admission NIHSS score, IV TPA treatment, and demographics. Results: After controlling for key covariates, AS immediately post-stroke and LSE were both associated with poorer day-90 mRS scores ( p <.001; p =.02 respectively), and higher AS was associated with poorer day-90 Fugl-Meyer scores ( p =.001). Higher LSE was indirectly associated with poorer day-90 Fugl-Meyer scores ( p =.009) through its association with high AS ( p <.001) upon admission. Conclusion: Lifetime stress and stress symptoms in the acute stroke setting are both associated with level of disability 3 months post-stroke; their assessment may be useful to facilitate early identification of high-risk patients and development of interventions that help improve functional outcomes after stroke.

Enhancing cognitive restructuring with concurrent fMRI-guided neurostimulation for emotional dysregulation–A randomized controlled trial

BackgroundTransdiagnostic clinical emotional dysregulation is a key component of many mental health disorders and offers an avenue to address multiple disorders with one transdiagnostic treatment. In the current study, we pilot an intervention that combines a one-time teaching and practice of cognitive restructuring (CR) with repetitive transcranial magnetic stimulation (rTMS), targeted based on functional magnetic resonance imaging (fMRI). MethodsThirty-seven clinical adults who self-reported high emotional dysregulation were enrolled in this randomized, double-blind, placebo-controlled trial. fMRI was collected as participants were reminded of lifetime stressors and asked to downregulate their distress using CR tactics. fMRI BOLD data were analyzed to identify the cluster of voxels within the left dorsolateral prefrontal cortex (dlPFC) with the highest activation when participants attempted to downregulate, versus passively remember, distressing memories. Participants underwent active or sham rTMS (10 Hz) over the left dlPFC target while practicing CR following emotional induction using recent autobiographical stressors. ResultsReceiving active versus sham rTMS led to significantly higher high frequency heart rate variability during regulation, lower regulation duration during the intervention, and higher likelihood to use CR during the week following the intervention. There were no differences between conditions when administering neurostimulation alone without the CR skill and compared to sham. Participants in the sham versus active condition experienced less distress the week after the intervention. There were no differences between conditions at the one-month follow up. ConclusionThis study demonstrated that combining active rTMS with emotion regulation training for one session significantly enhances emotion regulation and augments the impact of training for as long as a week. These findings are a promising step towards a combined intervention for transdiagnostic emotion dysregulation.

Lifetime stressor exposure, systemic inflammation during pregnancy, and preterm birth among Black American women

Although Black American mothers and infants are at higher risk for morbidity and mortality than their White counterparts, the biological mechanisms underlying these phenomena remain largely unknown. To investigate the role that lifetime stressor exposure, perceived stressor severity, and systemic inflammatory markers might play, we studied how these factors were interrelated in 92 pregnant Black American women. We also compared inflammatory marker levels for women who did versus did not go on to give birth preterm. During the early third trimester, women completed the Stress and Adversity Inventory for Adults to assess the stressors they experienced over their lifetime. Women also provided blood samples for plasma interleukin (IL)-6, IL-8, IL-1β, and tumor necrosis factor (TNF)-α quantification. Preterm births were identified by medical record review. Controlling for relevant covariates, there were significant positive associations between average levels of both overall and acute perceived stressor severity and plasma IL-1β levels. Controlling for perceived stress at assessment and exposure to racial discrimination did not affect these results. Mediation models revealed that exposure to more chronic stressors was related to higher plasma IL-1β levels, as mediated by higher average levels of overall perceived stressor severity. Exposure to fewer acute stressors was related to higher plasma IL-1β levels, as mediated by higher average levels of acute perceived stressor severity. Finally, women who went on to give birth preterm had higher levels of plasma IL-6. These data thus highlight the potential importance of assessing and addressing lifetime stressor exposure among mothers before and during maternal-infant care.

Specific and cumulative lifetime stressors in the aetiology of major depression: A longitudinal community-based population study.

Early-life stressful circumstances (i.e. childhood maltreatment) coupled with stressful events later in life increase the likelihood of subsequent depression. However, very few studies have been conducted to examine the specific and cumulative effects of these stressors in the development of depression. There is also a paucity of research that simultaneously considers the role of biological factors combined with psychosocial stressors in the aetiology of depression. Guided by the biopsychosocial model proposed by Engel, the present study aims to examine to what extent the experience of stressors across the lifespan is associated with depression while taking into account the role of genetic predispositions. Data analysed were from the Social and Psychiatric Epidemiology Catchment Area of the Southwest of Montreal (ZEPSOM), a large-scale, longitudinal community-based cohort study. A total of 1351 participants with complete information on the lifetime diagnoses of depression over a 10-year follow-up period were included in the study. Stressful events across the lifespan were operationalised as specific, cumulative and latent profiles of stressful experiences. Latent profile analysis (LPA) was used to explore the clustering of studied stressors including childhood maltreatment, poor parent-child relationship, and stressful life events. A polygenetic risk score was calculated for each participant to provide information on genetic liability. Multivariate logistic regression was used to examine the association between specific, cumulative and latent profiles of stressors and subsequent depression. We found that different subtypes of childhood maltreatment, child-parent bonding and stressful life events predicted subsequent depression. Furthermore, a significant association between combined effects of cumulative stressful experiences and depression was found [odds ratio (OR) = 1.20, 95% confidence interval (CI): 1.12-1.28]. Three latent profiles of lifetime stressors were identified in the present study and named as 'low-level of stress' (75.1%), 'moderate-level of stress' (6.8%) and 'high-level of stress' (18.1%). Individuals with a 'high-level of stress' had a substantially higher risk of depression (OR = 1.80, 95% CI: 1.08-3.00) than the other two profiles after adjusting for genetic predispositions, socio-demographic characteristics, and health-related factors. While controlling for genetic predispositions, the present study provides robust evidence to support the independent and cumulative as well as compositional effects of early- and later-on lifetime psychosocial stressors in the subsequent development of depression. Consequently, mental illness prevention and mental health promotion should target the occurrence of stressful events as well as build resilience in people so they can better cope with stress when it inevitably occurs.

Stressful Life Events and Risk of Illness among Urban Adolescents in Bangladesh

Introduction: Adolescence describes the year between 13 and 19 and can be considered the transitional stage from childhood to adulthood. The purpose of the study is to investigate the relationship between stressful life events and risk of illness during the period of adolescence. Methods: The study was carried out in two high schools namely Civil Aviation High School and Hossain Ali High School, Tejgaon, Dhaka. Dhaka is the most important capital city in Bangladesh. The duration of the study was 1 year, from 1st January to 31st December 2017. Results: Data on lifetime stress about common life events i.e., Romantic breakup (27.3%), family disruption (22.8%), Change in acceptance by peers (25.5%), Failure in grade in school (22.4%), Not making extracurricular activity (25.3%), Outstanding personal achievement (20.3%) were collected from 384 school-going adolescents. The association between each source of stressful life events and risk of illness was modeled in separate statistical analyses. The proportion of adolescents reporting about senior in college (29.9%), Breaking up with boy/girlfriends (27.3%), Changing in acceptance by friends (25.5%) change in parent’s financial status (25%), Failure in grading in school (22.4%) were statically significant. There was a positive relationship between the age of adolescents and getting the risk of illness (df, r, p) and negative relation with a monthly income of the family and getting the risk of illness (df, r, p). About half of the respondents were suffering from a slight risk of illness whether a small portion of respondents was in at risk of illness. The risk of illness is mildly associated with age, sex, monthly income of a family, and profession of the mother. Conclusion: Some stressful life events were strongly associated with the risk of illness. Any other occurrences of associated with stressful life events should be addressed properly to reduce the risk of illness.

The interplay of childhood maltreatment and lifetime stress with epigenetic age acceleration in psychiatric disease

The interplay of childhood maltreatment and lifetime stress with epigenetic age acceleration in psychiatric disease

Acute and Lifetime Stress and Psychotic Illness: The Roles of Reward and Salience Networks.

Affective reactions to acute stressors often evoke exacerbations of psychotic symptoms and sometimes de novo psychotic symptoms and initial psychotic episodes. Across the lifespan, affective reactions to acute stressors are enhanced by successive adverse childhood experiences (ACEs), in a process called "behavioral sensitization". The net effects of behavioral sensitization of acute stress responses are to alter responsivity to positive and negative feedback and to unexpected events, regardless of valence, leading to the maladaptive assignment of salience to stimuli and events. The assignment of "aberrant" salience to stimuli and events has profound consequences for learning and decision-making, which can influence both the positive and negative symptoms of psychosis. In this review, we discuss some of the psychological and neural mechanisms by which affective reactivity to acute stress, and its sensitization through the experience of stress and trauma across the lifespan, impact both the positive and negative symptoms of psychosis. We recount how the reward and salience networks of the brain, together with inputs from the dopamine and serotonin neurotransmitter systems, are implicated in both affective reactivity to stress and the symptoms of psychosis, likely mediate the effects of stress and trauma on the symptoms of psychosis and could serve as targets for interventions.

Childhood and adulthood traumatic events differentially associate with cognitive aging among Black and White elders in the Health and Retirement Study

AbstractBackgroundModifiable sociocontextual factors powerfully shape ADRD risk, and demonstrably contribute to well‐established racial disparities in cognitive aging. Stressful experiences occurring across the lifespan associate with brain aging and poor cognitive outcomes. However, the importance of timing and even type of stressor remains understudied. We examined relationships between childhood and adulthood traumatic events and cognition among non‐Hispanic Black and White older adults in the Health and Retirement Study (HRS).MethodThe sample included non‐demented adults (N=5,725) aged 65+ with lifetime stress data and complete cognitive testing at the 2006/08, 2010/12, and/or 2014/16 waves. Trauma measures included childhood (0‐11), and adulthood (0‐7) traumatic event counts. Outcomes included global cognition, immediate recall, and delayed recall (Telephone Interview for Cognitive Status). Each exposure‐outcome pair was investigated in separate linear mixed effect models including baseline trauma count, a quadratic trauma term to test for non‐linear relationships, and subject‐specific random intercept. Omnibus Likelihood Ratio Tests (LRT) were conducted to determine if number of traumatic events associated overall with each cognitive outcome. The sample was stratified by race before analysis.ResultBlack participants (N=651) were younger and reported less formal education than White participants (N=5,074). Number of traumatic events in adulthood did not vary by race, but Black participants reported slightly fewer childhood traumas (Table 1) than Whites. Among Whites, childhood traumas associated with poorer global cognition scores but traumas in adulthood showed very modest positive associations across cognitive domains. Among Black participants, no association between childhood trauma and later‐life cognition was observed. A significant non‐linear term for traumatic events indicated cross‐domain cognitive detriment associated with high exposure to adulthood trauma (Table 2; Figure 1).ConclusionAverage exposure to traumas (eg., physical abuse, life‐threatening illness) was low, and in both Black and White older adults, some limited exposure to traumatic events during adulthood predicted modest cognitive benefit. Black HRS participants reporting many traumatic events during adulthood, but not childhood, showed dysfunction in global cognition and recall. Findings highlight importance of adverse events across the full life course, potential threshold effects and co‐occuring chronic stress conditions, and a need to identify resources that buffer impacts of trauma on biology and personal environment.

Non-verbal cognitive development, learning, and symptoms of PTSD in 3- to 6-year-old refugee children

As IQ tests are commonly used as key assessment method, we address the question whether our commonly used standardized IQ tests are appropriate for children from families of diverse cultures and different educational levels in a refugee population. We examined 109 refugee children aged 3–7 years (M = 5.10 years, SD = 1.25) with the “Kaufman Assessment Battery for Children “ (KABC-II; Kaufmann & Kaufmann, 2015) on a language-free scale (Scale of Intellectual Functioning, SIF) and learning performance (subtest Atlantis). With a non-verbal IQ of 81.5 (SD = 18.01), the population mean of the refugee children is more than one standard deviation lower than the mean of the German norm population. Standardized scores follow the normal distribution and are not correlated to any of the assessed markers of adversity (flight duration, time spent in Germany, child PTSD in parent rating, parental symptom load, and parental education level).Conclusion: The interpretation of IQ test results for refugee children should be done cautiously as results may underestimate their cognitive capacity. Environmental factors, such as high illiteracy among parents in this study, the lack of institutional education of children and high lifetime stress, may explain our findings.Trial registration: DRKS00021150.What is Known:• There is a high pervasiveness for the use of standardized IQ tests in the German health and education system to determine eligibility for special education and social services.What is New:• Refugee children score significantly lower than German children in a language-free IQ test. As results are normally distributed and not correlated to any of the assessed markers of adversity, the low scores in the refugee group might be due to missing formal education.

Assessing lifetime stressor exposure in sport performers: Associations with trait stress appraisals, health, well-being, and performance

Research has found that greater lifetime stressor exposure increases the risk for mental and physical health problems. Despite this, few studies have examined how stressors occurring over the entire lifespan affect sport performers’ health, well-being, and performance, partly due to the difficulty of assessing lifetime stressor exposure. To address this issue, we developed a sport-specific stress assessment module (Sport SAM) for the Stress and Adversity Inventory (STRAIN) and then analyzed the instrument’s usability, acceptability, validity, and test-retest reliability. Furthermore, we examined whether trait-like tendencies to appraise stressful situations as a challenge or threat mediated the association between lifetime stressor exposure and health, well-being, and performance. Participants were 395 sport performers (Mage = 22.50 years, SD = 5.33) who completed an online survey. Results revealed that the Sport SAM demonstrated good usability and acceptability, good concurrent validity in relation to the Adult STRAIN (rs = 0.23 to 0.29), and very good test-retest reliability (ricc = 0.87 to 0.89). Furthermore, the Sport SAM was significantly associated with symptoms of depression (β = 0.21 to 0.24, ps ≤ .001) and anxiety (β = 0.13 to 0.19, ps ≤ .012), and general physical (β = 0.24 to 0.27, ps = ≤ 0.001) and mental (β = 0.23 to 0.32, p ≤ .001) health complaints. Finally, we found that associations between total lifetime non-sport and sport-specific stressor severity and health were mediated by trait stress appraisals. Consequently, these findings may help practitioners better identify sport performers who are at risk of developing stress-related health problems.

When Anger Remains Unspoken: Anger and Accelerated Epigenetic Aging Among Stress-Exposed Black Americans.

Race-related lifetime stress exposure (LSE) including racial discrimination, trauma, and stressful life events have been shown to contribute to racial health disparities. However, little is known about associations between race-related stressors and premature biological aging that confer the risk of adverse health outcomes. Even less is known about the mechanisms through which race-related stressors may be associated with accelerated aging. Early evidence suggests psychological processes such as anger, and particularly the internalization of anger, may play a role. In a community sample of predominantly low-income Black adults (n = 219; age = 45.91 [12.33] years; 64% female), the present study examined the association of race-related LSE (as defined by exposure to racial discrimination, trauma, and stressful life events) and epigenetic age acceleration through anger expression. Internalized and externalized anger expression were each significantly associated with LSE and age acceleration. Although LSE was not directly associated with age acceleration (ΔR2 = 0.001, p = .64), we found that greater LSE was indirectly associated with age acceleration through increases in internalized, but not externalized, anger (indirect effect: β = 0.03, standard error = 0.02, 95% confidence interval = 0.003 to 0.08; total effect: β = 0.02, 95% confidence interval = -0.25 to 0.31). These results suggest race-related LSE may elicit the internalization of anger, which, along with the externalization of anger, may initiate detrimental epigenetic alterations that confer the risk of adverse health outcomes. These findings lay the groundwork for longitudinal studies of the association between race-related stress and racial health disparities.

Using mobile sensing data to assess stress: Associations with perceived and lifetime stress, mental health, sleep, and inflammation

Using mobile sensing data to assess stress: Associations with perceived and lifetime stress, mental health, sleep, and inflammation

Ambient air pollution, psychological stress, and early childhood respiratory outcomes: Modifying effects of prenatal maternal diet, sex, and race/ethnicity

BACKGROUND AND AIM: Many lower income, racially/ethnically mixed communities experience co-occurring environmental hazards (i.e., pollutants, social inequities and related stress, poorer access to healthy foods) contributing to respiratory disease. Starting {in utero}, fine particulate matter (PM₂.₅) and stress disrupt similar but not completely overlapping processes, including oxidative stress, influencing respiratory health. Antioxidant intake can have protective effects. We examined associations among prenatal PM₂.₅, maternal stress, and antioxidant intake in relation to early childhood wheeze in a longitudinal pregnancy cohort in the Northeastern United States (N=539). METHODS: Daily prenatal PM₂.₅ exposure was estimated using a satellite-based spatiotemporally resolved model. Women completed the Lifetime Stressor Checklist-Revised (LSC-R). A prenatal antioxidant index (AI) was based on average percentile intake of beta-carotene, vitamins (A,C,E), zinc, magnesium, and selenium. Mothers reported child wheeze with follow-up to 4.1±2.8 years. Logistic regression was used to examine effects of prenatal AI and LSC-R on repeated wheeze (≥2 episodes); effect modification was explored in stratified models. Bayesian distributed lag interaction models (BDLIMs) were used to examine associations between prenatal PM₂.₅ exposure on wheeze, and effect modification by AI, race/ethnicity, and child sex. Covariates included maternal age, education, asthma, and temperature. RESULTS:Women were 39.3% black and 33% Hispanic with 35.6% reporting ≤high school education; 20.3% of children had repeated wheeze. The association between higher AI and decreased wheeze was significant only in blacks (Odds Ratio, OR=0.37, 95% confidence interval, CI: 0.19-0.73 per interquartile range increase). Higher stress was associated with repeated wheeze when AI was below the median, especially among blacks/Hispanics [OR=1.04 (1.01-1.06)]. BDLIMs found that cumulative effect on repeated wheeze per μg/m³ increase in PM₂.₅ across pregnancy was only significant in boys born to black mothers with low antioxidant intake [OR=1.2 (1.01-1.59)]. CONCLUSIONS:Relationships among prenatal PM₂.₅, stress, antioxidant intake, and child wheeze are complex and are modified by race/ethnicity and child sex. KEYWORDS: particulate matter, prenatal stress, nutrition, antioxidants, pediatric respiratory outcomes

Lifetime and perceived stress, social support, loneliness, and health in autistic adults.

Although the health consequences of life stress exposure in the general population are well known, how different stressors occurring over the lifetime cause morbidity and mortality in autism is unclear, as are the factors that moderate and mediate these associations. The few studies that have compared autistic and nonautistic individuals have used instruments that yield few stress exposure indices and assess stressors occurring over short time periods. To address these issues, we used the Stress and Adversity Inventory to assess lifetime stressor exposure and perceived stressor severity in 127 autistic and 104 nonautistic adults. Moderated mediation analysis examined associations between stressor exposure and physical and mental ill-health with respect to the hypothesized mediating role of stressor perception, and moderation effects of loneliness and social support. Autistic adults experienced more lifetime stressors and generally perceived stressors as being more severe. Greater perceived stressor severity was related to poorer physical and mental health and to greater loneliness and lower social support for both groups. An additional post hoc analysis of the association between diagnostic status and mental ill-health revealed that loneliness mediated the relation between being autistic and having poorer mental health. Autistic individuals experienced more lifetime stressors, and their impact on physical and mental health was mediated by perceived stressor severity. Moreover, loneliness and low social support were associated with greater negative impact of lifetime stress exposure on mental health. Interventions that reduce cognitive-perceptual stress appraisals, and that target loneliness and social support, may help reduce risk for stress-related disease in autistic individuals. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Lifetime stress exposure, cognition, and psychiatric wellbeing in women

Objectives:Although life stress has been associated with worse cognitive and psychiatric functioning, few studies on this topic have examined these associations in older adults and no studies to date have assessed lifetime stress exposure in this context. Method:To address this important issue, we investigated associations between lifetime stress exposure, cognition, and psychiatric wellbeing in 44 women aged 60 and older who completed a comprehensive lifetime stress exposure inventory, two memory tasks, and a complete psychiatric assessment. Results:As hypothesized, greater acute and chronic lifetime stress exposure were both related to poorer psychiatric functioning and more somatic health complaints. Greater lifetime stress exposure was also associated with poorer subjective cognition as indicated by memory and thought problems but not objective indices of memory function. Conclusion:Screening for high life stress exposure may therefore help identify older women at increased risk of experiencing negative psychiatric and cognitive outcomes.

Multiple dimensions of stress vs. genetic effects on depression

Many psychiatric disorders including depression involve complex interactions of genetics and environmental stressors. Environmental influence is challenging to measure objectively and account for in genetic studies because the necessary large population samples in these studies involve individuals with varying cultures and life experiences, clouding genetic findings. In a unique population with relative sociocultural homogeneity and a narrower range of types of stress experiences, we quantitatively assessed multiple stress dimensions and measured their potential influence in biasing the heritability estimate of depression. We quantified depressive symptoms, major lifetime stressors, current perceived stress, and a culturally specific community stress measure in individuals with depression-related diagnoses and community controls in Old Order Amish and Mennonite populations. Results showed that lifetime stressors measured by lifetime stressor inventory (R2 = 0.06, p = 2 × 10−5) and current stress measured by Perceived Stress Scale (R2 = 0.13, p < 1 × 10−6) were both associated with current depressive symptoms quantified by Beck Depression Inventory in community controls, but current stress was the only measure associated with current depressive symptoms in individuals with a depression diagnosis, and to a greater degree (R2 = 0.41, p < 1 × 10−6). A novel, culturally specific community stress measure demonstrated internal reliability and was associated with current stress but was not significantly related to depression. Heritability (h2) for depression diagnosis (0.46 ± 0.14) and quantitative depression severity as measured by Beck Depression Inventory (0.45 ± 0.12) were significant, but h2 for depression diagnosis decreased to 0.25 ± 0.14 once stressors were accounted for in the model. This quantifies and demonstrates the importance of accounting for environmental influence in reducing phenotypic heterogeneity of depression and improving the power and replicability of genetic association findings that can be better translated to patient groups.

Operational Lifetime–Stress Model for Complex Networks

While a number of network systems are running under certain stress with a limited lifetime, it is still unknown how to predict the lifetime–stress relation of complex systems. We develop a percolation-based approach to build an operational lifetime–stress model for complex networks, which captures the spatial and temporal reliability characteristics of the system. In this article, the general analytical expression for the entire operational lifetime–stress relation has been presented, which suggests that the load stress and the number of nodes in the network impact the operational lifetime in the same manner. The size effect found here in the lifetime–stress relation is observed for the first time, to our best knowledge. For 2-D lattices, we show that the lifetime–stress relation can be regarded as the combination of two parts—an approximately linear region for small stress, and nonlinear region for large stress. We also analyze the lifetime–stress function of Beijing road network and the western United States power grid. Our article might help to develop acceleration testing methods, which will facilitate better design of reliable complex systems.

Beyond WEIRD: Associations between socioeconomic status, gender, lifetime stress exposure, and depression in Madagascar.

Although research has examined associations between socioeconomic status (SES), gender, and acute and chronic life stressors in depression, most studies have been conducted in Western, educated, industrialized, rich, democratic (WEIRD) populations. We addressed this issue by interviewing 65 adults (55 women, M age = 37) living in Madagascar, a typical low- and middle-income country. As hypothesized, women experienced more life stressors and depressive symptoms, on average, than men, as did those from lower (vs. higher) SES backgrounds. Additionally, lifetime stress exposure was associated with greater symptoms of depression, accounting for 19% of the variability in depressive symptom levels. These effects differed for acute versus chronic and distal versus recent stressors. Finally, stress exposure significantly mediated the relation between SES and gender on depressive symptoms, accounting for 24.0%-70.8% of the SES/gender-depression association depending on stressor type. These data extend prior research by describing how social stratification and gender relate to lifetime stress exposure and depressive symptoms in a non-WEIRD population.