Mary H. Burleson

Loneliness and health: potential mechanisms.

Objective Two studies using cross-sectional designs explored four possible mechanisms by which loneliness may have deleterious effects on health: health behaviors, cardiovascular activation, cortisol levels, and sleep. Methods In Study 1, we assessed autonomic activity, salivary cortisol levels, sleep quality, and health behaviors in 89 undergraduate students selected based on pretests to be among the top or bottom quintile in feelings of loneliness. In Study 2, we assessed blood pressure, heart rate, salivary cortisol levels, sleep quality, and health behaviors in 25 older adults whose loneliness was assessed at the time of testing at their residence. Results Total peripheral resistance was higher in lonely than nonlonely participants, whereas cardiac contractility, heart rate, and cardiac output were higher in nonlonely than lonely participants. Lonely individuals also reported poorer sleep than nonlonely individuals. Study 2 indicated greater age-related increases in blood pressure and poorer sleep quality in lonely than nonlonely older adults. Mean salivary cortisol levels and health behaviors did not differ between groups in either study. Conclusions Results point to two potentially orthogonal predisease mechanisms that warrant special attention: cardiovascular activation and sleep dysfunction. Health behavior and cortisol regulation, however, may require more sensitive measures and large sample sizes to discern their roles in loneliness and health.

Loneliness in Everyday Life: Cardiovascular Activity, Psychosocial Context, and Health Behaviors

Prior lab research revealed higher basal total peripheral resistance (TPR) and lower cardiac output (CO) in lonely than in nonlonely young adults. In this study, experience sampling was used to obtain ambulatory blood pressure; impedance cardiography: and reports of activities, appraisals, interactions, and health behaviors. Results confirmed that loneliness predicted higher TPR and lower CO during a normal day. Loneliness did not predict differences in time spent alone, daily activities, or health behaviors but did predict higher stress appraisals and poorer social interactions. Independent of loneliness, interaction quality contributed to TPR. Loneliness differences were not mediated by depressed affect or neuroticism. Social support mediated loneliness differences in stress and threat. Concomitants of loneliness were comparable for men and women.

Lonely traits and concomitant physiological processes : the MacArthur social neuroscience studies

Loneliness is a complex set of feelings encompassing reactions to unfulfilled intimate and social needs. Although transient for some individuals, loneliness can be a chronic state for others. Prior research has shown that loneliness is a major risk factor for psychological disturbances and for broad-based morbidity and mortality. We examined differences between lonely and socially embedded individuals that might explain differences in health outcomes. Satisfying social relationships were associated with more positive outlooks on life, more secure attachments and interactions with others, more autonomic activation when confronting acute psychological challenges, and more efficient restorative behaviors. Individuals who were chronically lonely were characterized by elevated mean salivary cortisol levels across the course of a day, suggesting more discharges of corticotropin-releasing hormone and elevated activation of the hypothalamic-pituitary-adrenocorticol axis. An experimental manipulation of loneliness further suggested that the way in which people construe their self in relation to others around them has powerful effects on their self concept and, possibly, on their physiology.

Interpersonal Stress, Depression, and Disease Activity in Rheumatoid Arthritis and Osteoarthritis Patients

The relationships among interpersonal stressors, depression, coping inefficiency, hormones (prolactin, cortisol, and estradiol), and disease activity were examined. The sample comprised 33 women with rheumatoid arthritis (RAs; age 37-78) and 37 women with osteoarthritis (OAs; age 47-91), who served as controls. In a regression analysis, interpersonal conflict events accounted for more than twice as much variance in depression in RAs than in OAs. In the RA patients, the immune-stimulating hormones prolactin and estradiol were significantly positively correlated with interpersonal conflicts, depression, coping inefficacy, and clinician ratings of disease activity, suggesting that RAs are more reactive to interpersonal stressors than are OAs, both psychologically and physiologically.

Epstein-barr virus antibodies in whole blood spots: A minimally invasive method for assessing an aspect of cell-mediated immunity

Objective Study 1: Introduce and validate a method for measuring EBV p18-VCA antibodies in whole blood spots to provide a minimally invasive marker of cell-mediated immune function. Study 2: Apply this method to a large community-based study of psychopathology in children and adolescents. Methods The EBV antibody method was evaluated through analysis of precision, reliability, stability, and comparisons with plasma and indirect immunofluorescence methods. The effects of life events on p18-VCA antibody level were considered in a subsample of 9, 11, and 13 year-old children participating in the Great Smoky Mountains Study in North Carolina. The subsample was stratified by age, sex, and degree of overall life strain. Results Dried blood spots provided a convenient, sensitive, precise, and reliable method for measuring EBV p18-VCA antibody titer. Life events were positively associated with p18-VCA antibodies in girls but not in boys. Conclusions The validity of the blood spot EBV p18-VCA antibody assay, as well as the ease of sample collection, storage, and transportation, may provide an opportunity for psychoneuroimmunology to explore a wider range of stress models in larger, community-based studies.

Autonomic and Glucocorticoid Associations with the Steady-State Expression of Latent Epstein-Barr Virus

Previous studies have demonstrated the impact of psychological stress on the steady-state expression/reactivation of latent Epstein-Barr virus (EBV). Stress-induced decrements in the cellular immune response result in less control over the expression of the latent virus, resulting in increases in antibody to the virus. In Study 1, we investigated whether the steady-state expression of latent EBV in vivo differed between high and low stress reactors, as defined by sympathetic cardiac reactivity. Autonomic activity and antibody titers to Epstein-Barr virus capsid antigen (VCA) were measured in 50 elderly women latently infected with EBV. Results revealed that women who were high stress reactors were characterized by higher antibody titers to the latent virus than low stress reactors. High reactors tended to show larger stress-related increases in cortisol than low reactors, but the differences were not significant. Daily stressors can activate the autonomic nervous system and promote the release of pituitary and adrenal hormones, especially in high reactors. Glucocorticoid hormones have been shown to reactivate EBV in vitro from cells latently infected with the virus. We hypothesized that absolute levels of plasma cortisol may not be the only explanation for stress-induced reactivation of latent EBV and that the diurnal changes in the production of cortisol may be an important factor in these interactions. To examine the feasibility of this hypothesis, an in vitro study was conducted (Study 2) to determine whether changing glucocorticoid concentrations in the medium, in which EBV latently infected cells were cultured, to mimic diurnal changes in plasma cortisol concentrations would enhance the reactivation of the latent virus. Cells latently infected with EBV were exposed to either constant or varying concentrations of the synthetic glucocorticoid hormone dexamethasone (Dex), for 72 h. Results revealed a three- to eightfold enhancement of reactivation of latent EBV in cells pulsed with varying Dex concentrations when compared with cells exposed to a constant and/or a higher mean level of one Dex concentration. Together, these studies raise the possibility that differences in the kinetics of glucocorticoid concentrations may contribute to differences in the reactivation of latent EBV.

Autonomic and neuroendocrine responses to mild psychological stressors: Effects of chronic stress on older women

We investigated autonomic and endocrine responses to acute stressors in 27 women who were or are presently caring for a spouse with a progressive dementia (high chronic stress) and 37 noncaregivers who were category matched for age and family income (low chronic stress). Measures were taken before (low acute stress) and in response to brief laboratory stressors (high acute stress). We replicated prior research showing that caregivers report greater stress, depression, and loneliness than the comparison groups, and acute stressors elevate autonomic and neuroendocrine activity. We also found that caregivers, relative to noncaregivers, exhibited shorter preejection periods and elevated blood pressure and heart rate, but the magnitude of autonomic and neuroendocrine reactivity to the experimental stressors was comparable across these groups. This pattern of autonomic differentiation replicates prior research showing that caregivers are characterized by higher sympathetic activation than noncaregivers and suggests that the effects of chronic stress on physiological reactivity may be a less robust effect in older adults.

Neuroendocrine and cardiovascular reactivity to stress in mid-aged and older women: long-term temporal consistency of individual differences.

We report long-term temporal consistency of stress-related neuroendocrine and cardiovascular variables in mid-aged and older women who performed mental math and speech stress tasks two times approximately 1 year apart. Epinephrine, norepinephrine, ACTH, cortisol, cardiac preejection period (PEP), respiratory sinus arrhythmia, heart rate (HR), blood pressure, and respiration rate were measured at baseline, after or during stressors, and 30 min posttask. Although there were exceptions, year-to-year Spearman coefficients showed mostly moderate to high consistency (rs approximately equal to .5-.8) for baseline, stressor, and posttask values. For reactivity, HR and PEP were most consistent (rs approximately equal to .65); consistency for other variables was moderate to low (rs approximately equal to .1-.4). Means of most variables changed from year to year. Results support the use of baseline, stressor, and posttask values in longitudinal studies.

Cellular immune responses to acute stress in female caregivers of dementia patients and matched controls

This study investigated whether the stress of caregiving alters cellular immune responses to acute psychological stressors. Twenty-seven women caring for a spouse with a progressive dementia (high chronic stress) and 37 controls matched for age and family income performed a 12-min laboratory stressor. Cellular immune function was assessed by both functional and quantitative measures taken before (low acute stress), immediately after (high acute stress), and 30 min after (recovery from stress) exposure to the laboratory stressors. The laboratory challenges were associated with diminished proliferative responses but elevated natural killer (NK) cell cytotoxicity; however, subsequent analyses suggested that this elevated cytotoxicity was largely attributable to an increase in the number of NK cells in peripheral blood. The results suggest that although the stress of caregiving diminishes cellular immune function, caregiving appears to have little effect on cellular immune responses to or recovery from brief psychological challenges.

No evidence for menstrual synchrony in lesbian couples.

Menstrual synchrony was investigated in a sample of 29 cohabiting lesbian couples, ranging in age from 22 to 48 years. One or both partners kept prospective daily records of variables including menses onset dates, intimate contact, and sexual activity. All women reported daily intimate interaction with their partners; none reported intimate interaction with men. Despite these potentially optimal conditions for the manifestation of synchrony, the differences between dyad members in menses onset dates were distributed randomly, and there was no evidence of convergence. In fact, most dyads exhibited divergence of onset dates. Reasons for lack of synchrony in this sample are discussed; one conclusion is that there is no solid evidence that menstrual synchrony is a stable attribute of past or contemporary human populations.