Social Stress

Objective: Results from animal and human studies suggest that disregulations of the hypothalamus-pituitary-adrenal (HPA) axis are involved in several behavioral, circulatory, endocrine, and immune disorders with clear-cut gender differences in disease prevalence. The aim of the present study was to investigate sex-specific HPA response patterns with a focus on the contribution of gonadal steroids as possible mediators. Methods: A total of 81 healthy adults were investigated in the present study. Twenty men, 19 women in the follicular phase of the menstrual cycle, 21 women in the luteal phase, and 21 women using oral contraceptives (OC) were exposed to a brief psychosocial stress test (Trier Social Stress Test; TSST) and injected with 0.25 mg ACTH 1-24 on consecutive days. Basal HPA activity was investigated by repeatedly measuring cortisol levels immediately after awakening, as well as in 30-minute intervals from 9:00 AM to 9:00 PM. Additionally, questionnaires were used to assess psychological state and trait parameters. Results: Results show that the TSST induced significant increases in ACTH, salivary-free cortisol, total plasma cortisol, and heart rates, as well as increased wakefulness and reduced calmness in the total group. Significant group differences emerged for ACTH and salivary-free cortisol stress responses: Although men showed higher ACTH responses to the TSST compared with each of the three groups of women, salivary cortisol responses showed the following response pattern: Luteal ϭ Men Ͼ Follicular ϭ OC. The salivary cortisol responses to ACTH 1-24 showed a similar response pattern: Luteal Ͼ Men Ͼ Follicular Ͼ OC. In contrast, total blood cortisol levels did not reveal any group difference between sexes or follicular versus luteal phase in either test. Although a similar salivary-free cortisol increase after awakening was found in the four groups, the circadian cortisol profile was significantly different throughout the first 4 hours of sampling. Questionnairederived psychological variables, as measured in the present study, could not explain the observed results. Conclusions: We conclude that gender, menstrual cycle phase, and OC use exert important effects on HPA responsiveness to psychosocial stress in healthy subjects. Although men seem to have a stronger hypothalamic drive in response to stressful stimulation than women, differences in salivary-free cortisol levels, at least in part, may be explained by estradiol-induced changes in corticosteroid-binding protein levels. ACTH and cortisol secretion is not affected by OC use per se but the amount of bioavailable unbound cortisol ("free") is greatly reduced in this group of women after stimulation. Inasmuch as none of these differences between the study groups emerged in total blood cortisol levels, we strongly advocate for the simultaneous measurement of free and total cortisol levels in future studies on HPA functioning.

Recent studies have demonstrated that the free cortisol response to awakening can serve as a useful index of hypothalamus-pituitary-adrenal axis (HPA) activity. This endocrine marker is rather consistent, shows good intraindividual stability across time and appears to be able to uncover subtle changes in HPA regulation. The present twin study investigated genetic factors as sources of the interindividual variation of the cortisol awakening response. Furthermore, the relationship between psychological variables and morning cortisol levels was studied.

Using a social stress perspective, the authors studied the mental health effects of added burden related to socially disadvantaged status (being African American or Latino, female, young, and identifying as bisexual vs. gay or lesbian) in a community sample of 396 self-identified lesbian, gay, and bisexual (LGB) adults. Mental health outcomes were social and psychological well-being contrasted with depressive symptoms. When mental health deficiencies by disadvantaged social status were detected, the authors examined whether LGB community connectedness and positive sexual identity valence played a mediating role, reducing the social status disparity in outcome. The authors found different patterns when looking at social versus psychological well-being and positive versus negative mental health outcomes. Bisexuality and young age, but not gender and raciaVethnic minority status, were associated with decreased social well-being. In bisexuals, this relationship was mediated by community connectedness and sexual identity valence. Although no differences in social or psychological well-being were found by gender, female gender was associated with depressed mood. The authors conclude that thke is limited support for an additive stress model.

Objective: Racism has been identified as a psychosocial stressor that may contribute to disparities in the prevalence of cardiovascular disease. The goal of the present article was to investigate the relationship of perceived racism to ambulatory blood pressure (ABP) in a sample of American-born Blacks and Latinos. Methods: Participants included English-speaking Black or Latino(a) adults between the ages of 24 and 65. They completed daily mood diaries and measures of perceived racism, socioeconomic status, and hostility. Participants were outfitted with ABP monitors; 357 provided data on waking hours only, and 245 provided data on both waking and nocturnal night-time ABP. Results: Perceived racism was positively associated with nocturnal ABP even when controlling for personality factors and socioeconomic status. Conclusions: The results suggest that racism may influence cardiovascular disease risk through its effects on nocturnal BP recovery. Key words: ambulatory blood pressure, racism, discrimination, cardiovascular disease, ecological momentary assessment, hypertension.

This paper summarises the available evidence that failure of defense mechanisms in (semi)-natural social groups of animals may lead to serious forms of stress pathology. Hence the study of social stress may provide animal models with a high face validity. However, most of the animal models of human stress-disorders have concentrated on the consequences of chronic exposure to stressors. The present paper considers recent data, indicating that a single experience with a major stressor in the form of social defeat may have long-term consequences ranging from hours to days and weeks. It seems that the experience of a major stressor sensitizes the animal to subsequent stressors. The consequences of these long-term temporal dynamics of the stress response to the development of stress-related disorders and stress-vulnerability are discussed.

TORNATZKY, W. AND K. A. MICZEK. Long-term impairment of autonomic circadian rhythms after brief intermittent social stress. PHYSIOL BEHAV 53(5) 983-993, 1993.--This experiment was designed to examine the short-and long-term behavioral, cardiovascular, and thermoregulatory responses to brief intermittent agonistic confrontations in rats. The experimental procedure involves resident-intruder confrontations consisting of a 10-min period during which both animals are separated in the home cage of the resident, followed by a brief physical encounter leading to defeat of the intruder and a 10-rain period, when the intruder was alone in the home cage of the resident. These 30-min-long confrontations were repeated on 5 consecutive days. Before the first confrontation with a resident, an intruder rat's telemetered heart rate and core temperature show a stable circadian rhythm that is entrained by the light cycle. Acutely, the confrontations produce immediate and large tachycardia and hyperthermia in intruders. A decrease in amplitude of the circadian rhythms for heart rate and core temperature, as detected by cosinor analysis, persists for at least 10 days after the last of five daily brief confrontations with the resident. The defensive upright posture is nearly absent during the first exploration of the resident's home cage, but is displayed by the intruder for one-third of the available time before and after the fifth defeat. Intermittent brief social stress is sut~cient to induce profound changes in defensive behavior and long-lasting depression of circadian rhythmicity that persist for weeks.

In two investigations, we studied vulnerability to the negative effects of stress among women in chronic pain from 2 types of musculoskeletal illnesses, fibromyalgia syndrome (FMS) and osteoarthritis (OA). In Study 1, there were 101 female participants 50 to 78 years old: 50 had FMS, 29 had OA knee pain and were scheduled for knee surgery, and 22 had OA but were not planning surgery. Cross-sectional analyses showed that the three groups were comparable on demographic variables, personality attributes, negative affect, active coping, and perceived social support. As expected, FMS and OA surgery women reported similar levels of bodily pain, and both groups scored higher than OA nonsurgery women. However, women with FMS reported poorer emotional and physical health, lower positive affect, a poorer quality social milieu, and more frequent use of avoidant coping with pain than did both groups of women with OA. Moreover, the perception and use of social support were closely tied to perceived social stress only among the FMS group. In Study 2, we experimentally manipulated negative mood and stress in 41 women 37 to 74 years old: 20 women had FMS, and 21 women had OA. Participants from each group were randomly assigned to either a negative mood induction or a neutral mood (control) condition, and then all participants discussed a stressful interpersonal event for 30 min. Stress-related increases in pain were exacerbated by negative mood induction among women with FMS but not women with OA, and pain during stress was associated with decreases in positive affect in women with FMS but not women with OA. These findings suggest that among women with chronic pain, those with FMS may be particularly vulnerable to the negative effects of social stress. They have fewer positive affective resources, use less effective pain-coping strategies, and have more constrained social networks than their counterparts with OA, particularly those who experience similar levels of pain. They also seem to experience more prolonged stress-related increases in pain under certain circumstances, all of which may contribute to a lowering of positive affect and increased stress reactivity over time. (Ann Behav Med 2001, 23(3):215-226)