Sex differences in HPA axis responses to stress: a review

Building conditions, 5-HTTLPR genotype, and depressive symptoms in adolescent males and females

PURPOSE

Emerging work suggests that both environmental and genetic factors contribute to risk of depression in adolescents, and that these factors may differ between genders. We assessed whether features of the social environment (SE), measured at varying levels, and genetic factors jointly contribute to the risk of depression in adolescent males and females.

METHODS

Using data from a national survey of U.S. adolescents, we applied cross-sectional, multilevel mixed models to assess the contribution of: (i) 5-HTTLPR genotype and respondent-level building conditions to depressive symptom score (DSS); and (ii) 5-HTTLPR genotype and neighborhood-level building conditions to DSS. Models testing potential gene-SE interactions were also conducted. All models were stratified by gender and adjusted for age, race/ethnicity, family structure, parental education, and social support.

RESULTS

Among females, adjusted analyses indicated that sl genotype carriers enjoyed a marginally significant (p = .07) protective effect against higher DSS in models assessing respondent-level building conditions. In contrast, among males, adjusted analyses predicted significantly higher DSS for residents of neighborhoods with relatively poor building conditions (p < .01). No significant gene-SE interactions were detected for either gender.

CONCLUSIONS

These results suggest that adverse, macro-level SE factors increase risk of depression to a greater extent in adolescent males than in females. Intervention strategies designed to improve mental health in adolescent populations should consider a growing body of work suggesting that the contextual factors conferring increased risk of depression differ among males and females.

Medical comorbidity of full and partial posttraumatic stress disorder in US adults: results from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions

OBJECTIVE

This study examined associations between lifetime trauma exposures, PTSD and partial PTSD, and past-year medical conditions in a nationally representative sample of US adults.

METHODS

Face-to-face interviews were conducted with 34,653 participants in the Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions. Logistic regression analyses evaluated associations of trauma exposure, PTSD, and partial PTSD with respondent-reported medical diagnoses.

RESULTS

After adjustment for sociodemographic characteristics and comorbid Axis I and II disorders, respondents with full PTSD were more likely than traumatized respondents without full or partial PTSD (comparison group) to report diagnoses of diabetes mellitus, noncirrhotic liver disease, angina pectoris, tachycardia, hypercholesterolemia, other heart disease, stomach ulcer, human immunodeficiency virus seropositivity, gastritis, and arthritis (odds ratios [ORs] = 1.2-2.5). Respondents with partial PTSD were more likely than the comparison group to report past-year diagnoses of stomach ulcer, angina pectoris, tachycardia, and arthritis (ORs = 1.3-1.6). Men with full and partial PTSD were more likely than controls to report diagnoses of hypertension (both ORs = 1.6), and both men and women with PTSD (OR = 1.8 and OR = 1.6, respectively) and men with partial PTSD (OR = 2.0) were more likely to report gastritis. The total number of lifetime traumatic event types was associated with many assessed medical conditions (ORs = 1.04-1.16), reducing the magnitudes and rendering some of the associations between PTSD status and medical conditions nonsignificant.

CONCLUSIONS

Greater lifetime trauma exposure and PTSD are associated with numerous medical conditions, many of which are stress-related and chronic, in US adults. Partial PTSD is associated with intermediate odds of some of these conditions.

Phasic deactivation of the medial temporal lobe enables working memory processing under stress

Demanding cognitive tasks are sometimes carried out under stressful conditions. Several studies indicate that whereas severe stress impairs performance, moderate stress can enhance cognitive performance. In this study, we investigated how moderate stress influences the neural systems supporting working memory. We embedded an N-back working memory task in a moderately stressful context, as indicated by our physiological stress measures, and probed phasic and tonic human brain activity using two fMRI-techniques: conventional blood oxygen level dependent fMRI and arterial spin labeling (ASL). The results showed that the stress induction, as compared to the neutral control condition, led to slightly faster reaction times without changes in accuracy. In general, working memory processing was associated with increased activity in a frontoparietal network and reduced activity in the medial temporal lobe (MTL). The stress induction led to enhanced reduction of phasic MTL responses, specifically the hippocampus and amygdala. In addition, ASL showed that stress increased tonic amygdala activity, while tonic hippocampal activity was unaffected. These findings suggest that the influence of stress on MTL deactivation during working memory processing is task-related rather than a general consequence of the stressful state. The temporal suspension of hippocampal processing in favor of more task relevant processes may allow subjects to maintain normal performance levels under moderate stress.

Interpersonal stress regulation and the development of anxiety disorders: an attachment-based developmental framework

Anxiety disorders represent a common but often debilitating form of psychopathology in both children and adults. While there is a growing understanding of the etiology and maintenance of these disorders across various research domains, only recently have integrative accounts been proposed. While classical attachment history has been a traditional core construct in psychological models of anxiety, contemporary attachment theory has the potential to integrate neurobiological and behavioral findings within a multidisciplinary developmental framework. The current paper proposes a modern attachment theory-based developmental model grounded in relevant literature from multiple disciplines including social neuroscience, genetics, neuroendocrinology, and the study of family factors involved in the development of anxiety disorders. Recent accounts of stress regulation have highlighted the interplay between stress, anxiety, and activation of the attachment system. This interplay directly affects the development of social-cognitive and mentalizing capacities that are acquired in the interpersonal context of early attachment relationships. Early attachment experiences are conceptualized as the key organizer of a complex interplay between genetic, environmental, and epigenetic contributions to the development of anxiety disorders - a multifactorial etiology resulting from dysfunctional co-regulation of fear and stress states. These risk-conferring processes are characterized by hyperactivation strategies in the face of anxiety. The cumulative allostatic load and subsequent "wear and tear" effects associated with hyperactivation strategies converge on the neural pathways of anxiety and stress. Attachment experiences further influence the development of anxiety as potential moderators of risk factors, differentially impacting on genetic vulnerability and relevant neurobiological pathways. Implications for further research and potential treatments are outlined.

Sex Differences in Pain Responses at Maturity Following Neonatal Repeated Minor Pain Exposure in Rats

There is mounting evidence of long-lasting changes in pain sensitivity in school-age children who were cared for in a neonatal intensive care unit. Such care involves multiple pain exposures, 70% of which are accounted for by heel lance to monitor physiological well-being. The authors sought to model the repeated brief pain resulting from heel lance by administering repeated paw needle stick to neonatal rat pups. Repeated needle stick during the first 8 days of life was sex-specific in altering responses to mechanical and inflammatory stimuli, but not to a thermal stimulus, at maturity. Specifically, neonatal paw needle stick males exhibited significantly greater mechanical sensitivity in response to von Frey hair testing, whereas neonatal paw needle stick females exhibited significantly greater pain behavior scores following hindpaw formalin injection. This is the first study to show such sex-dependent changes in pain responsiveness at maturity in animals having experienced repeated neonatal needle stick pain. These findings support existing evidence that there are long-term sensory sequelae following neonatal pain experiences in rats and further suggest that there are sex-linked differences in the nature of the consequences. If these relationships hold in humans, these findings suggest that even mild painful insults early in life are not without sensory consequences.

Male rats with the testicular feminization mutation of the androgen receptor display elevated anxiety-related behavior and corticosterone response to mild stress

Testosterone influences the hypothalamic-pituitary-adrenal axis, anxiety-related behavior, and sensorimotor gating in rodents, but little is known about the role of the androgen receptor (AR) in mediating these influences. We compared levels of the stress hormone corticosterone at baseline and following exposure to a novel object in an open field in wild type (wt) male and female rats, and male rats with the testicular feminization mutation (Tfm) of the AR, which disables its function. Basal corticosterone was equivalent in all groups, but exposure to a novel object in an open field elicited a greater increase in corticosterone in Tfm males and wt females than in wt males. Tfm males also showed increased behavioral indices of anxiety compared to wt males and females in the test. Analysis of the immediate early gene c-Fos expression after exposure to a novel object revealed greater activation in Tfm males than wt males in some regions (medial preoptic area) and lesser activation in others (dentate gyrus, posterodorsal medial amygdala). No differences were found in a measure of sensorimotor gating (prepulse inhibition of the acoustic startle response), although Tfm males had an increased acoustic startle response compared to wt males and females. These findings demonstrate that ARs play a role in regulating anxiety-related behaviors, as well as corticosterone responses and neural activation following exposure to a mild stressor in rats.

Immune, inflammatory and cardiovascular consequences of sleep restriction and recovery

In addition to its effects on cognitive function, compelling evidence links sleep loss to alterations in the neuroendocrine, immune and inflammatory systems with potential negative public-health ramifications. The evidence to suggest that shorter sleep is associated with detrimental health outcomes comes from both epidemiological and experimental sleep deprivation studies. This review will focus on the post-sleep deprivation and recovery changes in immune and inflammatory functions in well-controlled sleep restriction laboratory studies. The data obtained indicate non-specific activation of leukocyte populations and a state of low-level systemic inflammation after sleep loss. Furthermore, one night of recovery sleep does not allow full recovery of a number of these systemic immune and inflammatory markers. We will speculate on the mechanism(s) that link(s) sleep loss to these responses and to the progression of cardiovascular disease. The immune and inflammatory responses to chronic sleep restriction suggest that chronic exposure to reduced sleep (<6 h/day) and insufficient time for recovery sleep could have gradual deleterious effects, over years, on cardiovascular pathogenesis with a heightened risk in women and in night and shift workers. Finally, we will examine countermeasures, e.g., napping or sleep extension, which could improve the recovery processes, in terms of alertness and immune and inflammatory parameters, after sleep restriction.

Female responses to acute and repeated restraint stress differ from those in males

Chronic stress is implicated in diseases which differentially affect men and women. This study investigated how the activation of neuronal subpopulations contributes to changes in neuroendocrine regulation that predispose members of each sex to stress-related health challenges. Adult male and female rats were restrained in single (acute) or 14 consecutive daily (repeated) 30 min sessions; brain sections were immunohistochemically stained for Fos, arginine vasopressin (AVP) or glucocorticoid receptor (GR) within the paraventricular hypothalamic nucleus (PVH). Acute restraint increased the number of PVH cells expressing Fos, with greater increases in males than females. Habituated responses were seen following repeated stress in both sexes, with no sex differences between groups. No sex differences were found in the number of neurons co-expressing Fos and AVP. Absolute counts of cellular Fos and GR co-localization mirrored Fos expression. In contrast, when doubly-labeled cells were normalized to staining for Fos alone, females showed greater numbers of Fos- and GR-positive cells than males after both acute and repeated stress. These data demonstrate that sex-specific stress responses are evident at the level of neuronal activation, and may contribute to different consequences of chronic stress in females versus males. Females may be more sensitive to glucocorticoid negative feedback, suggesting that sex-dependent differences in the efficiency of initiating and terminating stress responses may exist. Understanding the neural and endocrine pathways that mediate these functions in males and females will inform targeted therapeutic strategies to alleviate stress and the sex-specific afflictions with which it is associated.

Neonatal respiratory infection and adult re-infection: effect on glucocorticoid and mineralocorticoid receptors in the hippocampus in BALB/c mice

Stressful events during the perinatal period in both humans and animals have long-term consequences for the development and function of physiological systems and susceptibility to disease in adulthood. One form of stress commonly experienced in the neonatal period is exposure to bacterial and viral infections. The current study investigated the effects of live Chlamydia muridarum bacterial infection at birth followed by re-infection in adulthood on hippocampal glucocorticoid receptors (GR) and mineralocorticoid receptors (MR) and stress response outcomes. Within 24 h of birth, neonatal mice were infected intranasally with C. muridarum (400 inclusion-forming units [ifu]) or vehicle. At 42 days, mice were re-infected (100 ifu) and euthanized 10 days later. In males, infection in adulthood alone had the most impact on the parameters measured with significant increases in GR protein compared to adult infection alone; and significant increases MR protein and circulating corticosterone compared to other treatment groups. Neonatal infection alone induced the largest alterations in the females with results showing reciprocal patterns for GR protein and TH protein. Perinatal infection resulted in a blunted response following adult infection for both males and females across all parameters. The present study demonstrates for the first time that males and females respond differently to infection based on the timing of the initial insult and that there is considerable sex differences in the hippocampal phenotypes that emerge in adulthood after neonatal infection.

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.

Biological mechanisms underlying the relationship between stress and smoking: state of the science and directions for future work

Theories of addiction implicate stress as a crucial mechanism underlying initiation, maintenance, and relapse to cigarette smoking. Examinations of the biological stress systems, including functioning of the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS), have provided additional insights into the relationship between stress and smoking. To date, convergent data suggests that chronic cigarette smoking is associated with alterations in HPA and ANS functioning; however, less is known about the role of HPA and ANS functioning in smoking initiation and relapse following cessation. In order to organize existing findings and stimulate future research, the current paper summarizes the available literature on the roles of HPA axis and ANS functioning in the relationship between stress and cigarette smoking, highlights limitations within the existing literature, and suggests directions for future research to address unanswered questions in the extant literature on the biological mechanisms underlying the relationship between stress and smoking.

Self-assessed parental depressive problems are associated with blunted cortisol responses to a social stress test in daughters. The TRAILS Study

Depression runs in families and is considered a stress-related disorder. Familial risk for depression may be transmitted via deregulated psychophysiological stress responses from parent to child. In this study, we examined the association between self-assessed lifetime parental depressive problems (PDP) and adolescent offspring' cortisol responses to a social stress test. Data were collected as part of the third assessment wave of TRAILS (TRacking Adolescents' Individual Lives Survey), a large prospective population study of Dutch adolescents. Data of 330 adolescents (mean age 16.04; 40.9% girls) who participated in a laboratory session, including a standardized performance-related social stress task (public speaking and mental arithmetic) were examined. Four saliva cortisol samples were collected before, during and after the social stress task which were analyzed with repeated measures Analysis of Variance. Lifetime parental depressive problems were assessed by self-reports from both biological parents. PDP was associated with daughter' cortisol responses (F(3,133)=3.90, p=.02), but no association was found in sons (F(3,193)=0.27, p=.78). Girls whose parents ever experienced depressive symptoms displayed a blunted cortisol response to the standardized social stress test, while girls whose parents never had such problems displayed the characteristic curvilinear response pattern. This effect was not mediated by offspring stress history (age 0-16). Analyses were corrected for smoking behaviour and adolescent depressed mood. The fact that PDP were measured by self-report questionnaires and did not reflect clinical DSM-IV diagnosis could be considered a limitation of the study.

Advances in multidisciplinary and cross-species approaches to examine the neurobiology of psychiatric disorders

Current approaches to dissect the molecular neurobiology of complex neuropsychiatric disorders such as schizophrenia and major depression have been rightly criticized for failing to provide benefits to patients. Improving the translational potential of our efforts will require the development and refinement of better disease models that consider a wide variety of contributing factors, such as genetic variation, gene-by-environment interactions, endophenotype or intermediate phenotype assessment, cross species analysis, sex differences, and developmental stages. During a targeted expert meeting of the European College of Neuropsychopharmacology (ECNP) in Istanbul, we addressed the opportunities and pitfalls of current translational animal models of psychiatric disorders and agreed on a series of core guidelines and recommendations that we believe will help guiding further research in this area.

A randomised placebo-controlled trial of oral hydrocortisone for treating tobacco withdrawal symptoms

RATIONALE

Many smokers experience a decline in cortisol to sub-normal levels during the first days of smoking cessation. A greater decline in cortisol is associated with more intense cigarette withdrawal symptoms, urge to smoke and relapse to smoking. Findings from an uncontrolled study suggest that glucocorticoids could ameliorate cigarette withdrawal.

OBJECTIVES

We investigated whether taking oral hydrocortisone would reduce withdrawal symptoms and the desire to smoke on the first day of temporary smoking abstinence compared with placebo.

METHODS

Using a double-blind within-subject randomised crossover design, 48 smokers took a single dose of 40 mg hydrocortisone, 20 mg hydrocortisone or placebo following overnight smoking abstinence. Abstinence was maintained through the afternoon, and withdrawal symptoms and the desire to smoke were rated across the morning. Salivary cortisol was assessed in the afternoon prior to abstinence (baseline) and while abstinent after each treatment.

RESULTS

There was a significant dose-response relation between dose of hydrocortisone and reduction in depression and anxiety ratings while abstinent, but there were no other statistically significant associations with dose. Overall, the decline in cortisol following smoking cessation (placebo only) was not significant. Cortisol level on the afternoon of smoking abstinence was not significantly associated with symptom ratings.

CONCLUSIONS

Supplements of hydrocortisone do not reduce the desire to smoke but may ameliorate withdrawal-related depression and anxiety, although the clinical benefit is slight.

Does midbrain urocortin 1 matter? A 15-year journey from stress (mal)adaptation to energy metabolism

This review summarizes some of the milestones of the research on the biological functions(s) of midbrain urocortin 1 (Ucn1) since its discovery 15 years ago. Detailed characterization of Ucn1 in the midbrain revealed its overall significance in food intake and regulation of homeostatic equilibrium and mood under stress. In addition, we have recently found a conspicuous alteration in midbrain Ucn1 levels in brains of depressed suicide victims. Furthermore, from the results from the genetically modified animals, a picture is emerging where corticotrophin-releasing factor promotes the initial reactions to stress, whereas Ucn1 seems to be crucial for management of the later adaptive phase. In the case of imbalance in action of these principle stress mediators, vulnerability to stress-related brain diseases is enhanced.

Molecular and cellular sex differences at the intersection of stress and arousal

Elucidating the mechanisms underlying sex biases in the prevalence and severity of diseases can advance our understanding of their pathophysiological basis and serve as a guide for developing treatments. A well-established sex difference in psychiatry is the higher incidence of mood and anxiety disorders in females. These disorders share stress as a potential etiological contributor and hyperarousal as a core symptom, suggesting that the distinction between sexes lies at the intersection of stress and arousal systems. This review focuses on the link between the stress axis and the brain norepinephrine arousal system as a key point at which sex differences occur and are translated to differences in the expression of mood disorders. Evidence for a circuit designed to relay emotion-related information via the limbic corticotropin-releasing factor (CRF) system to the locus coeruleus (LC)-norepinephrine arousal system is reviewed. This is followed by recent novel findings of sex differences in CRF receptor signaling and trafficking that would result in an enhanced arousal response and a compromised ability to adapt to chronic stress in females. Finally, we discuss the evidence for sex differences in LC dendritic structure that allow for an increased receipt and processing of limbic information in females compared to males. Together these complementary sets of data suggest that in females, the LC arousal system is poised to process more limbic information and to respond to some of this information in an enhanced manner compared to males. The clinical and therapeutic considerations arising from this perspective are discussed. This article is part of a Special Issue entitled 'Anxiety and Depression'.

Gender differences in the relationship between parental report of self-regulation skills and adolescents' management of type 1 diabetes

OBJECTIVE

To examine the extent to which self-regulation skills of adolescents with type 1 diabetes (T1D), including executive functioning and emotion regulation, relate to treatment adherence and glycemic control.

METHOD

Participants were 109 adolescents aged 12-18 yr with TID and their primary caregiver who attended an outpatient appointment at a pediatric endocrinology clinic. Parents and adolescents completed a measure of treatment adherence. Parents completed a self-regulation measure while a glycemic control measure [i.e., hemoglobin A1c (HbA1c)] was collected.

RESULTS

For boys, executive functioning and emotion regulation deficits were significantly associated with worse treatment adherence and glycemic control. Further analyses indicated that emotion regulation was the primary self-regulation measure related to treatment adherence and glycemic control. No significant associations were found for girls.

CONCLUSION

For adolescent boys, the ability to cope with various stressors and emotions may be as important as higher-order thinking skills for maximizing treatment adherence and diabetes control. Clinical implications and potential mechanisms by which emotion regulation skills relate to adolescent boys' diabetes treatment management are discussed.

Gender differences in the effect of early life trauma on hypothalamic-pituitary-adrenal axis functioning

BACKGROUND

The objective of this study was to examine the modifying effect of gender on the association between early life trauma and the hypothalamic-pituitary-adrenal (HPA) axis response to a pharmacologic challenge and a social stress task in men and women. Participants (16 men, 23 women) were the control sample of a larger study examining HPA axis function. Individuals with major depressive disorder, posttraumatic stress disorder, bipolar disorder, or psychotic or eating disorders were excluded.

METHODS

In two test sessions, subjects received 1 µg/kg of corticotropin-releasing hormone (CRH) intravenously and participated in the Trier Social Stress Test (TSST). Primary outcomes included plasma cortisol and corticotropin levels measured at baseline and more than five time points following the challenges. Predictors included gender and early life trauma, as measured by the Early Trauma Index. Using factor analysis, the domains general trauma, severe trauma, and the effects of trauma were established. Using regression, these constructs were used to predict differential HPA reactivity in men and women following the challenges.

RESULTS

The three factors accounted for the majority of the variance in the ETI. Following the CRH challenge, women had higher overall corticotropin response as dictated by the area under the curve analysis. There were no significant associations between trauma and neuroendocrine response to the TSST.

CONCLUSIONS

CRH challenge results indicate that gender differences in the impact of early trauma may help explain the differential gender susceptibility to psychopathology following adverse childhood events. This may help explain gender differences in some stress-sensitive psychiatric disorders.

Acute stress impairs memory retrieval independent of time of day

It is widely recognized that acute stress and associated glucocorticoid stress responses yield memory-enhancing effects when the memory consolidation phase is targeted, while impairing effects are generally found with regard to memory retrieval performance. While some evidence exists that the memory-enhancing effects of consolidation stress are modulated by time of day, no study to date has investigated whether stress-induced retrieval deficits are also prone to such time of day effects. To address this issue, participants (N=76) were exposed to a stressor or control condition before a retrieval test that probed for neutral and negative words learned 24h before. Results show that stress exposure resulted in impaired retrieval of both neutral and negative words, but that time of day did not moderate this effect. This memory-impairing effect was larger for negative than for neutral information, and was significantly associated with stress-induced cortisol responses. The current findings demonstrate the robustness of stress-induced retrieval deficits throughout the day, in particular for emotional memory material, and further underscore the importance of cortisol reactivity in impairing memory retrieval.

Implications of psychosocial stress on memory formation in a typical male versus female student sample

Stress is known to differentially modulate memory function. Memory can be impaired or strengthened by stress, depending on e.g. the memory type and phase under study, the emotional value of the learned information and the sex of the subjects. Here, we addressed the latter and investigated the impact of psychosocial stress on long-term memory for neutral and emotional pictures and working memory in typical samples of male versus female students. In total, 77 subjects (54 women of which 39 used oral contraceptives) were exposed to either the Trier Social Stress Test (TSST) or a control condition, and then engaged in a long-term memory task (emotionally arousing and neutral pictures; surprise recall after one week) and a working memory (n-back) task. During the experiment salivary cortisol and alpha-amylase levels as well as subjective affect state were assessed. As expected, stress hormone concentrations as well as subjective negative affect states increased significantly in response to the stress task. Men reacted more to the stressor in terms of cortisol responses than women, probably due to oral contraceptive use of the latter. Results show that, in male as well as in female students, memory for emotional arousing information was better than for neutral information, in both the stress and control condition. Stress enhanced recognition memory for emotional versus neutral pictures only in male subjects. Moreover, stress enhanced working memory, particularly in males, during the first block of a 2-back task. The lack of stress effects on memory in women might be explained by oral contraceptive use, leading to blunted HPA-axis responses and secondary to reduced stress effects on memory. The results emphasize that stress affects both long-term and working memory differentially in male versus female students.

Acute stress alters auditory selective attention in humans independent of HPA: a study of evoked potentials

BACKGROUND

Acute stress is a stereotypical, but multimodal response to a present or imminent challenge overcharging an organism. Among the different branches of this multimodal response, the consequences of glucocorticoid secretion have been extensively investigated, mostly in connection with long-term memory (LTM). However, stress responses comprise other endocrine signaling and altered neuronal activity wholly independent of pituitary regulation. To date, knowledge of the impact of such "paracorticoidal" stress responses on higher cognitive functions is scarce. We investigated the impact of an ecological stressor on the ability to direct selective attention using event-related potentials in humans. Based on research in rodents, we assumed that a stress-induced imbalance of catecholaminergic transmission would impair this ability.

METHODOLOGY/PRINCIPAL FINDINGS

The stressor consisted of a single cold pressor test. Auditory negative difference (Nd) and mismatch negativity (MMN) were recorded in a tonal dichotic listening task. A time series of such tasks confirmed an increased distractibility occurring 4-7 minutes after onset of the stressor as reflected by an attenuated Nd. Salivary cortisol began to rise 8-11 minutes after onset when no further modulations in the event-related potentials (ERP) occurred, thus precluding a causal relationship. This effect may be attributed to a stress-induced activation of mesofrontal dopaminergic projections. It may also be attributed to an activation of noradrenergic projections. Known characteristics of the modulation of ERP by different stress-related ligands were used for further disambiguation of causality. The conjuncture of an attenuated Nd and an increased MMN might be interpreted as indicating a dopaminergic influence. The selective effect on the late portion of the Nd provides another tentative clue for this.

CONCLUSIONS/SIGNIFICANCE

Prior studies have deliberately tracked the adrenocortical influence on cognition, as it has proven most influential with respect to LTM. However, current cortisol-optimized study designs would have failed to detect the present findings regarding attention.

Influence of acute stress on spatial tasks in humans

Few studies have investigated the relationship between stress and spatial performance in humans. In this study, participants were exposed to an acute laboratory stressor (Star Mirror Tracing Task) or a control condition (watching a nature video) and then performed two spatial tasks. In the first task, participants navigated through a virtual reality (VR) environment and then returned to the environment to make directional judgments relating to the learned targets. In the second task, perspective taking, participants made directional judgments to targets after imagined body rotations with respect to a map. Compared to the control condition, participants in the Stress condition showed increases in heart rate and systolic and diastolic blood pressure indicating sympathetic adrenal medulla (SAM) axis activation. Participants in the Stress condition also reported being more anxious, angry, frustrated, and irritated than participants in the Non-Stress condition. Salivary cortisol did not differ between conditions, indicating no significant hypothalamic-pituitary-adrenocortical (HPA) axis involvement. In the VR task, memory encoding was unaffected as directional error was similar in both conditions; however, participants in the Stress condition responded more slowly, which may be due to increases in negative affect, SAM disruption in spatial memory retrieval through catecholamine release, or a combination of both factors. In the perspective taking task, participants were also slower to respond after stress, suggesting interference in the ability to adopt new spatial orientations. Additionally, sex differences were observed in that men had greater accuracy on both spatial tasks, but no significant Sex by Stress condition interactions were demonstrated.

Stress and epilepsy: multiple models, multiple outcomes

Human studies show a link between stress and epilepsy, with stress causing an increase in seizure frequency and severity in patients with epilepsy. Many different animal model systems have been used to better understand this connection and the possible mechanisms involved. This review highlights the results of such studies relating stress and seizure susceptibility, with a focus on the hypothalamic-pituitary-adrenal axis and its relationship to seizure generation. The effects of hypothalamic-pituitary-adrenal axis mediators, acute stress, chronic stress, and early life stress on the seizure phenotype are summarized. Results suggest that stress has both anticonvulsive and proconvulsive properties, depending on the animal strain and the stress/seizure induction paradigm used. Attempts to interpret the stress-epilepsy literature must take these variables into account. The growing availability of genetically modified mice that carry either human epilepsy mutations or mutations in stress pathway genes now provide the opportunity to examine the relationship between stress and epilepsy more directly.

Racial and ethnic patterns of allostatic load among adult women in the United States: findings from the National Health and Nutrition Examination Survey 1999-2004

OBJECTIVE

This study provides a descriptive sociodemographic profile of allostatic load (AL) among adult women of all age groups, focusing on how age patterns of AL vary across racial/ethnic groups. Allostatic load, an index of cumulative physiological dysregulation, captures how the cumulative impact of physiological stress responses from person-environment interactions causes wear and tear on the body's regulatory systems, which in turn can lead to disease outcomes and health disparities.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2004, this study examines AL in a nationally representative sample of women ≥18 years of age (n=5765). Measures of AL using 10 biomarkers representing cardiovascular, inflammatory, and metabolic system functioning were created. Multivariate negative binomial regression models were used, and predicted AL scores were computed.

RESULTS

Black women had the highest predicted AL scores relative to other racial/ethnic groups, and a marked black/white gap in AL persisted across all age groups. Age by race/ethnicity interaction terms revealed significant racial/ethnic differences in AL patterns across age groups. Black women 40-49 years old had AL scores 1.14 times higher than white women 50-59 years old, suggesting earlier health deterioration. Mexican women not born in the United States had lower predicted AL scores than those born in the United States.

CONCLUSIONS

This study provides one of the first descriptive profiles of AL among a nationally representative sample of adult women in the United States and presents racial/ethnic trends in AL across age groups that are useful for identifying demographically and clinically important subgroups at risk of having high cumulative physiological dysregulation.

Adrenocortical responses to strangers in preschoolers: relations with parenting, temperament, and psychopathology

Previous research has provided inconsistent evidence for the relations between young children's hypothalamic-pituitary-adrenal (HPA) functioning and their temperament, parenting, and adjustment. Building biopsychosocial models of adjustment, we examined how temperamental inhibition and maternal punishment contributed to preschoolers' adrenocortical activity while interacting with adult strangers. We also examined whether HPA functioning moderated relations between dispositional and familial factors and children's internalizing and externalizing problems. A total of 402 preschool-aged children from three independent samples with parallel and overlapping measures were studied. Salivary cortisol levels were measured twice while interacting with adult strangers during testing protocols. Mothers reported on temperamental inhibition, maternal punishment and children's problems. Maternal punishment predicted higher cortisol levels 20 and 65 min after meeting adult strangers. Prolonged cortisol elevation was associated with having fewer externalizing problems. Boys who experienced more maternal punishment and had higher cortisol 20 min after meeting strangers manifested more externalizing problems. Girls who were more inhibited and had prolonged cortisol elevations had more internalizing problems. In accord with biopsychosocial models of psychopathology, HPA functioning in preschoolers was sensitive to variations in socialization experiences, and moderated children's risk for emotional and behavioral problems.

Sex differences in physiological and affective responses to stress in remitted depression

Major depressive disorder (MDD) is associated with alterations in stress physiology. Severe melancholic depression is characterized by hypercortisolism, but community dwelling mildly depressed individuals and those with remitted MDD have shown reduced or normal reactivity to stress. There are also pronounced sex differences both in the incidence of MDD and in stress reactivity. To explore the relationships among depression history, sex differences, and stress, we examined stress reactivity in people with and without a history of MDD. Twenty-two participants with remitted MDD (12 men and 10 women) and 36 never depressed comparison participants (22 men and 14 women) participated in the study. Cortisol and alpha-amylase (sAA) were sampled from saliva before, 10 min after, and 30 min after the Trier Social Stress Test (TSST). Participants filled out the Positive Affect Negative Affect Schedule (PANAS) before and after they underwent the TSST. Women with remitted MDD showed reduced cortisol response to the TSST compared with the never MDD women, while men with remitted MDD showed comparable cortisol reactivity to the never depressed men. The groups did not differ on sAA reactivity to stress. The remitted MDD group (overall and men and women separately) reported greater negative affect both before and after stress compared to the never depressed group. Women from both groups reported greater post-stress negative affect than men. In contrast, men from both groups reported higher positive affect before and after stress than women. Given that the sex difference findings were not dependent on depression history, self-reported affective differences in response to stress may predate depressive symptoms and contribute to sex differences in depression incidence.

Chronic stress, cognitive functioning and mental health

This review aims to discuss the evidence supporting the link between chronic stress, cognitive function and mental health. Over the years, the associations between these concepts have been investigated in different populations. This review summarizes the findings that have emerged from older populations as well as from populations suffering from pathological aging, namely Mild Cognitive Impairment and Alzheimer's Disease. Although older adults are an interesting population to study in terms of chronic stress, other stress-related diseases can occur throughout the lifespan. The second section covers some of these stress-related diseases that have recently received a great deal of attention, namely burnout, depression, and post-traumatic stress disorder. Given that chronic stress contributes to the development of certain pathologies by accelerating and/or exacerbating pre-existing vulnerabilities that vary from one individual to the other, the final section summarizes data obtained on potential variables contributing to the association between chronic stress and cognition.

Effect of childhood physical abuse on cortisol stress response

RATIONALE

Abuse and neglect are highly prevalent in children and have enduring neurobiological effects. Stressful early life environments perturb the hypothalamic-pituitary-adrenal (HPA) axis, which in turn may predispose to psychiatric disorders in adulthood. However, studies of childhood maltreatment and adult HPA function have not yet rigorously investigated the differential effects of maltreatment subtypes, including physical abuse.

OBJECTIVE

In this study, we sought to replicate our previous finding that childhood maltreatment was associated with attenuated cortisol responses to stress and determine whether the type of maltreatment was a determinant of the stress response.

METHODS

Salivary cortisol response to the Trier Social Stress Test (TSST) was examined in a non-clinical sample of women (n = 110). Subjects had no acute medical problems and were not seeking psychiatric treatment. Effects of five maltreatment types, as measured by the Childhood Trauma Questionnaire, on cortisol response to the TSST were investigated. To further examine the significant (p < 0.005) effect of one maltreatment type, women with childhood physical abuse (PA) (n = 20) were compared to those without past PA (n = 90).

RESULTS

Women reporting childhood PA displayed a significantly blunted cortisol response to the TSST compared with subjects without PA, after controlling for estrogen use, age, other forms of maltreatment, and other potential confounds. There were no differences between PA and control groups with regard to physiological arousal during the stress challenge.

CONCLUSIONS

In a non-clinical sample of women with minimal or no current psychopathology, physical abuse is associated with a blunted cortisol response to a psychosocial stress task.

The impact of cortisol reactivity to acute stress on memory: sex differences in middle-aged people

Stress has been identified as a main factor involved in the cognitive changes that occur during the aging process. This study investigated sex differences in the relationship between the magnitude of the acute stress-induced salivary cortisol response and memory performance among middle-aged people. To this end, 16 men and 16 women (aged 54-72 years) were exposed to the Trier Social Stress Test and a control condition in a crossover design. Afterwards their memory performance was measured using a standardized memory test (Rey's Auditory Verbal Learning Test). Only among women, there was an acute impact of stress on memory performance and a significant relationship between a higher cortisol response to the stressor and poorer memory performance in both the stress and control conditions. Additionally, a poorer memory performance was related to earlier timing of sexual maturation (age at menarche), which was also marginally related to higher cortisol reactivity to stress. These results confirm that sex is a critical factor in the relationship between cortisol and poor memory performance. Furthermore, the findings emphasize a strong link between the individual cortisol response to stress and memory functioning among postmenopausal women.

Neurobiological and psychiatric consequences of child abuse and neglect

The effects of early-life trauma and its consequences for the treatment of depression are reviewed. The prevalence and clinical sequelae of early sexual and physical abuse, neglect and parental loss are described. An overview of preclinical studies that help guide clinical research and practice is presented. Human clinical studies on the neurobiological consequences of early trauma are summarized. Moderating factors, such as genetic variation and sex differences, are discussed. The few current treatment outcome studies relevant to this research area are described. Guidance for the management of patients with depression and a history of child abuse and neglect are provided. Most patients who have experienced early traumatic experiences are likely best treated with a combination of psychotherapy and pharmacotherapy. This review is dedicated to the memory of Seymour Levine who pioneered the field of early experience research and to a considerable extent inspired the clinical studies described in this review.

Sex differences in synaptic plasticity in stress-responsive brain regions following chronic variable stress

Increased stress responsiveness is implicated in the etiology of mood and anxiety disorders, including depression and post-traumatic stress disorder. Additionally, stress-related affective disorders have a higher incidence in women than men. Chronic stress in rodents produces numerous neuromorphological changes in a variety of limbic brain regions. Here, we examined the sex-dependent differences in presynaptic innervation of the paraventricular nucleus of the hypothalamus (PVN), prefrontal cortex (PFC), bed nucleus of the stria terminalis (BST), and amygdala in response to chronic variable stress (CVS). Following 14 days of CVS, the presynaptic protein synaptophysin was assessed in male and female rats. Our results demonstrate that synaptophysin staining density was higher in females than males in all brain areas evaluated, indicating sex differences in the organization of presynaptic innervation. After CVS, the PVN, principal nucleus of the BST (BSTpr), and basolateral nucleus of the amygdala (BLA) displayed significantly reduced synaptophysin density in females but not males. Furthermore, males showed an increase in synaptophysin in the PVN after CVS, suggesting a sex difference in the modulation of presynaptic inputs to the PVN following chronic stress. Overall, these data suggest marked sex differences in PVN, BSTpr, and BLA presynaptic innervation as a consequence of chronic stress, which may be associated with differential stress responsivity and perhaps susceptibility to pathologies in males and females.

The relationship between psychosocial stress, age, BMI, CRP, lifestyle, and the metabolic syndrome in apparently healthy subjects

The aim of this cross-sectional study was to examine the factors which may be associated with the metabolic syndrome by exploring the relationship between psychosocial stress, age, body mass index (BMI), C-reactive protein (CRP), lifestyle factors, and the components of the metabolic syndrome, such as glycated hemoglobin (HbA1c), fasting blood sugar (FBS), body fat percentage, and triglyceride concentration, among apparently healthy subjects. Psychosocial stress was measured by the use of the inventory to measure psychosocial stress (IMPS). One thousand four hundred and ninety-nine people out of 1,941 public school workers admitted to a hospital for a medical check-up responded to the IMPS, yielding a response rate of 77.2%. A total of 1,201 workers excluding 298 who were taking medication for various diseases were analyzed with the use of hierarchical multiple regression models. It was found that IMPS-measured stress score, age, BMI, and smoking habit were associated with an increase in glycated hemoglobin among men, while alcohol consumption was associated with a decrease in glycated hemoglobin. Stress score, age, BMI, and alcohol consumption were found to be associated with an increase in FBS among men, while smoking and exercise habits were associated with a decrease in FBS. CRP was found to be associated with an increase in body fat percentage among men, though stress score was not associated with an increase in body fat percentage. Stress score, age, and BMI were associated with an increase in triglyceride concentration among women. The findings of the present study seem to be in line with the hypothesis that psychosocial stress plays an important role in developing the metabolic syndrome, which may be associated with inflammatory processes in the vascular wall, resulting in atherosclerosis and cardiovascular disease.

Influence of consumption of a high-protein vs. high-carbohydrate meal on the physiological cortisol and psychological mood response in men and women

Consumption of meals with different macronutrient contents, especially high in carbohydrates, may influence the stress-induced physiological and psychological response. The objective of this study was to investigate effects of consumption of a high-protein vs. high-carbohydrate meal on the physiological cortisol response and psychological mood response. Subjects (n = 38, 19 m/19f, age =25 ± 9 yrs, BMI  = 25.0 ± 3.3 kg/m²) came to the university four times, fasted, for either condition: rest-protein, stress-protein, rest-carbohydrate, stress-carbohydrate (randomized cross-over design). Stress was induced by means of a psychological computer-test. The test-meal was either a high-protein meal (En% P/C/F 65/5/30) or a high-carbohydrate meal (En% P/C/F 6/64/30), both meals were matched for energy density (4 kJ/g) and daily energy requirements (30%). Per test-session salivary cortisol levels, appetite profile, mood state and level of anxiety were measured. High hunger, low satiety (81 ± 16, 12 ± 15 mm VAS) confirmed the fasted state. The stress condition was confirmed by increased feelings of depression, tension, anger, anxiety (AUC stress vs. rest p < 0.02). Consumption of the high-protein vs. high-carbohydrate meal did not affect feelings of depression, tension, anger, anxiety. Cortisol levels did not differ between the four test-sessions in men and women (AUC nmol·min/L p > 0.1). Consumption of the test-meals increased cortisol levels in men in all conditions (p < 0.01), and in women in the rest-protein and stress-protein condition (p < 0.03). Men showed higher cortisol levels than women (AUC nmol·min/L p < 0.0001). Consumption of meals with different macronutrient contents, i.e. high-protein vs. high-carbohydrate, does not influence the physiological and psychological response differentially. Men show a higher meal-induced salivary cortisol response compared with women.

Chronic alcohol neuroadaptation and stress contribute to susceptibility for alcohol craving and relapse

Alcoholism is a chronic relapsing disorder. Major characteristics observed in alcoholics during an initial period of alcohol abstinence are altered physiological functions and a negative emotional state. Evidence suggests that a persistent, cumulative adaptation involving a kindling/allostasis-like process occurs during the course of repeated chronic alcohol exposures that is critical for the negative symptoms observed during alcohol withdrawal. Basic studies have provided evidence for specific neurotransmitters within identified brain sites being responsible for the negative emotion induced by the persistent cumulative adaptation following intermittent-alcohol exposures. After an extended period of abstinence, the cumulative alcohol adaptation increases susceptibility to stress- and alcohol cue-induced negative symptoms and alcohol seeking, both of which can facilitate excessive ingestion of alcohol. In the alcoholic, stressful imagery and alcohol cues alter physiological responses, enhance negative emotion, and induce craving. Brain fMRI imaging following stress and alcohol cues has documented neural changes in specific brain regions of alcoholics not observed in social drinkers. Such altered activity in brain of abstinent alcoholics to stress and alcohol cues is consistent with a continuing ethanol adaptation being responsible. Therapies in alcoholics found to block responses to stress and alcohol cues would presumably be potential treatments by which susceptibility for continued alcohol abuse can be reduced. By continuing to define the neurobiological basis of the sustained alcohol adaptation critical for the increased susceptibility of alcoholics to stress and alcohol cues that facilitate craving, a new era is expected to evolve in which the high rate of relapse in alcoholism is minimized.

Multiple measures elucidate glucocorticoid responses to environmental variation in predation threat

Predator-induced changes in the glucocorticoid responses of prey have been proposed to mediate indirect predator effects on prey demography. Ambiguities exist, however, as to whether differences in predation threat in the environment at large affect the mean glucocorticoid response in wild birds and mammals, and whether this is likely to affect reproduction. Most studies to date that have examined glucocorticoid responses to environmental variation in predation threat have evaluated just one of the several potential measures of the glucocorticoid response, and this may be the source of many ambiguities. We evaluated multiple measures of the glucocorticoid response [plasma total CORTicosterone, corticosteroid binding globulin (CBG) and free CORT] in male and female song sparrows (Melospiza melodia) sampled at locations differing in predation threat in the environment at large, where we have previously reported reproductive differences suggestive of indirect predator effects. Total CORT varied markedly with predation threat in males but not females whereas the opposite was true for CBG, and both sexes demonstrated the same moderately significant free CORT response. Considering all three indices, a glucocorticoid response to environmental variation in predation threat was evident in both sexes, whereas there were ambiguities considering each index singly. We conclude that collecting multiple physiological measures and conducting multivariate analyses may provide a preferable means of assessing glucocorticoid responses to environmental variation in predation threat, and so help clarify whether such glucocorticoid changes affect reproduction in wild birds and mammals.

Stress in Migrant Farmworkers During Premigration

Purpose: This study explored the relationship between migrant farmworker (MFW) stress and salivary cortisol (sC) in a sample of MFWs prior to migration. Sample: The sample, 40 ( N = 14 male, 26 female) adult MFWs residing in the lower Rio Grande Valley of Texas, primarily comprised middle-aged immigrants with a middle-school education. Design: This pilot feasibility study included a self-report farmworker stress inventory and five serial sC specimens in 24 hr. Results: The sC measures reflected an expected diurnal pattern. Lower total cortisol (area under the curve with respect to ground) was significantly associated with greater waist circumference ( r = –.63, p ≤ .01). Repeated measures analysis of variance (ANOVA) indicated that participants who perceived high levels of farmworker stress exhibited a significant change in sC over time; F(2.14, 72.65) = 43.90, p < .001. High- and low-perceived-stress groups differed significantly in the trajectory of changes in sC over the five time points. Conclusion: MFWs experienced significant levels of stress during premigration. Their sC responses varied significantly by level of perceived farmworker stress. Lower perceived stress may reflect blunting of the sC response pattern.

Differential effects of 17β-estradiol and 11-ketotestosterone on the endocrine stress response in zebrafish (Danio rerio)

Sexually dimorphic stress responses are present in species across all vertebrate taxa and it has been suggested that these effects are mediated by circulating sex steroids. While a few species of fish have been identified as having a sexually dimorphic stress response, there is conflicting evidence as to the effects of sex steroids on the stress axis. In this study, we tested whether zebrafish exhibit a sexually dimorphic cortisol stress response and whether 17β-estradiol (E2) or 11-ketotestosterone (11KT) modulate the activity of the hypothalamic-pituitary-interrenal (HPI) axis. To accomplish this, we quantified the whole body cortisol response to a physical stressor, cortisol release in vitro, and the expression of key HPI axis regulating genes of control and E2- or 11KT-exposed zebrafish. Under control conditions no dimorphisms in the HPI axis were apparent at rest or in response to a standardized stressor. In contrast, E2-exposure blunted the cortisol response of male fish in vivo and in vitro and as well as corticotropin-releasing factor (crf) expression in the pre-optic area (POA) of the brain. While the expression of some interrenal genes was suppressed by E2-exposure, these changes occurred in both male and female zebrafish. 11KT-exposure increased whole-body cortisol of males at rest and vortex-exposed females, but had no impact on the rate of cortisol synthesis in vitro or on POA crf expression. Therefore, while we found no evidence that zebrafish exhibit a sexually dimorphic cortisol stress response, both E2 and 11KT can modulate the activity of the HPI axis in this species and do so via different mechanisms.

Litter gender composition and sex affect maternal behavior and DNA methylation levels of the oprm1 gene in rat offspring

The mu-opioid receptor is encoded by the Oprm1 gene and contributes to mother-infant behaviors. Rodent dams lick male pups more than female pups in the anogenital region. This behavior is linked to stress responsivity in the offspring that may be mediated by epigenetic changes. We hypothesized that maternal behavior may affect DNA methylation levels of the Oprm1 gene and show sex differences. To further explore sex differences in mother-pup behaviors and DNA methylation levels, we altered the litter gender composition (LGC) of rats. Litters were culled to eight all male, all female, or four male/four female pups on postnatal (PN) day 1. On PN4, 7, and 10, a dam was placed in a test cage with a pup for a 10-min period. Latency to pup contact was determined as were times spent licking the anogenital and other body regions of the pup. Frequencies of other behaviors were tabulated. On PN35, samples from various brain regions were obtained. DNA methylation at specific CpG sites in the Oprm1 promoter region were measured by direct sequencing of bisulfite-treated DNA. LGC and sex interacted with day for latency to pup contact. Latencies were longest on PN4 for single-sex males and on PN10 for single-sex females. Dams licked male pups more than female pups in both the anogenital and other body areas. Sex differences were seen in other behaviors. LGC altered DNA methylation at specific CpG's of Oprm1 in hippocampus with higher levels in single-sex rats. In nucleus accumbens, single-sex males showed hypermethylation levels, a trend seen in caudate-putamen. Results confirm and extend sex differences in maternal care with modest LGC effects. That both LGC and sex have enduring effects on DNA methylation of the Oprm1 gene in brain regions associated with addiction, stress regulation, motivation, and cognition may suggest one factor that contributes to gender differences in these behaviors.

Endocrine and psychological stress responses in a simulated emergency situation

BACKGROUND

Several studies have assessed the effects of training using patient simulation systems on medical skills. However, endocrine and psychological stress responses in a patient simulation situation and the relationship between stress reactivity and medical performance have been studied rarely, so far.

METHODS

Medical students (18 males and 16 females) who had completed at least two months anaesthesiology training participated in the study. In a counterbalanced cross-over design they were subjected to three conditions: rest, laboratory stress (LS; public speaking), and simulated emergency situation (SIM; myocardial ischemia and ventricular fibrillation). Salivary cortisol and psychological responses (visual analogue scales, VAS) were assessed every 15 min from 15 min prior to until 60 min after intervention. Differences between stress and rest conditions were analysed. Medical performance was assessed according to the European Resuscitation Council's Guidelines for Resuscitation.

RESULTS

As compared to rest, cortisol increased significantly in both stress conditions with different time courses in LS and SIM. Psychological responses in SIM exceeded those in LS. Cortisol increase in LS (r(s)=.486; p=.019) but not in SIM (r(s)=.106; p=.631) correlated significantly with medical performance.

DISCUSSION

A simulated emergency situation is a profound stressor. The positive relationship between endocrine stress responsiveness in a standard laboratory situation and medical performance in a simulated emergency situation indicates that high stress responsiveness might be a predictor of good performance. At the same time the high stress response might counteract educational efforts associated with training using high-fidelity patient simulation.

Heroin reduces startle and cortisol response in opioid-maintained heroin-dependent patients

Heroin dependence (HD) is a chronic relapsing brain disorder characterized by a compulsion to seek and use heroin. Stress is seen as a key factor for heroin use. Methadone maintenance and the prescription of pharmaceutical heroin [diacetylmorphine (DAM)] are established treatments for HD in several countries. The present study examined whether DAM-maintained patients and methadone-maintained patients differ from healthy controls in startle reflex and cortisol levels. Fifty-seven participants, 19 of each group matched for age, sex and smoking status, completed a startle session which included the presentation of 24 bursts of white noise while eye-blink responses to startling noises were recorded. Salivary cortisol was collected three times after awakening, before, during and after the startle session. DAM was administered before the experiment, while methadone was administered afterwards. Both heroin-dependent patient groups exhibited significantly smaller startle responses than healthy controls (P < 0.05). Whereas the cortisol levels after awakening did not differ across the three groups, the experimental cortisol levels were significantly lower in DAM-maintained patients, who received their opioid before the experiment, than in methadone-maintained patients and healthy controls (P < 0.0001). Opioid maintenance treatment for HD is associated with reduced startle responses. Acute DAM administration may suppress cortisol levels, and DAM maintenance treatment may represent an effective alternative to methadone in stress-sensitive, heroin-dependent patients.

Gender differences in stress response: Role of developmental and biological determinants

Stress response is associated with manifestations of various psychosomatic and psychiatric disorders. Hence, it is important to understand the underlying mechanisms that influence this association. Moreover, men and women tend to react differently with stress-both psychologically and biologically. These differences also need to be studied in order to have a better understanding in the gender difference observed for many disorders, which are likely to be contributed by the gender difference in stress reactivity and responses. Such an understanding would have a significant impact on our understanding about how adult health is set during early life and how adult disease could be prevented in men and women.

Sex differences in behavioral and corticosterone responses to mild stressors in ICR mice are altered by ovariectomy in peripubertal period

Among rodents, females are generally considered to be highly responsive in terms of emotionality under stressful conditions, and have higher corticosterone levels and activity. In this study, we examined sex differences in mice by evaluating anxiety behaviors and corticosterone responses to mild stressors. In our first experiment, we analyzed the behavioral and corticosterone responses to the elevated plus-maze test and open-field test in male and female mice, and compared sex differences. Principal component analysis (PCA) was used to investigate the correlation of these responses between males and females. The corticosterone level was higher in females under both basal and stressed conditions. In the behavioral response, higher locomotor activity was seen in females in the elevated plus-maze test. PCA showed little association among anxiety behavior, locomotor activity, and corticosterone secretion. In our second experiment, we examined the activational effects of sex steroids on the corticosterone response to the elevated plus-maze test by gonadectomizing male and female mice and using testosterone or estrogen capsules as hormonal replacements. Sex differences at the basal corticosterone level were not altered by the hormonal milieu in adults, however the higher corticosterone level of females in response to stress was diminished by ovariectomy, although replacement with neither testosterone nor estrogen had any effect. These results suggest that the sex difference in novelty exposure observed in the form of a greater hypothalamic-pituitary-adrenal (HPA) axis response in female ICR mice is controlled by ovary-derived factors in adults.

Sex differences in neural responses to stress and alcohol context cues

Stress and alcohol context cues are each associated with alcohol-related behaviors, yet neural responses underlying these processes remain unclear. This study investigated the neural correlates of stress and alcohol context cue experiences and examined sex differences in these responses. Using functional magnetic resonance imaging, brain responses were examined while 43 right-handed, socially drinking, healthy individuals (23 females) engaged in brief guided imagery of personalized stress, alcohol-cue, and neutral-relaxing scenarios. Stress and alcohol-cue exposure increased activity in the cortico-limbic-striatal circuit (P < 0.01, corrected), encompassing the medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), left anterior insula, striatum, and visuomotor regions (parietal and occipital lobe, and cerebellum). Activity in the left dorsal striatum increased during stress, while bilateral ventral striatum activity was evident during alcohol-cue exposure. Men displayed greater stress-related activations in the mPFC, rostral ACC, posterior insula, amygdala, and hippocampus than women, whereas women showed greater alcohol-cue-related activity in the superior and middle frontal gyrus (SFG/MFG) than men. Stress-induced anxiety was positively associated with activity in emotion-modulation regions, including the medial OFC, ventromedial PFC, left superior-mPFC, and rostral ACC in men, but in women with activation in the SFG/MFG, regions involved in cognitive processing. Alcohol craving was significantly associated with the striatum (encompassing dorsal, and ventral) in men, supporting its involvement in alcohol "urge" in healthy men. These results indicate sex differences in neural processing of stress and alcohol-cue experiences and have implications for sex-specific vulnerabilities to stress- and alcohol-related psychiatric disorders.

The Adaptive Calibration Model of stress responsivity

This paper presents the Adaptive Calibration Model (ACM), an evolutionary-developmental theory of individual differences in the functioning of the stress response system. The stress response system has three main biological functions: (1) to coordinate the organism's allostatic response to physical and psychosocial challenges; (2) to encode and filter information about the organism's social and physical environment, mediating the organism's openness to environmental inputs; and (3) to regulate the organism's physiology and behavior in a broad range of fitness-relevant areas including defensive behaviors, competitive risk-taking, learning, attachment, affiliation and reproductive functioning. The information encoded by the system during development feeds back on the long-term calibration of the system itself, resulting in adaptive patterns of responsivity and individual differences in behavior. Drawing on evolutionary life history theory, we build a model of the development of stress responsivity across life stages, describe four prototypical responsivity patterns, and discuss the emergence and meaning of sex differences. The ACM extends the theory of biological sensitivity to context (BSC) and provides an integrative framework for future research in the field.