John M. Ernst

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.

Cognitive and Physiological Antecedents of Threat and Challenge Appraisal

Cognitive appraisal theories of stress and emotion propose that cognitive appraisals precede physiological responses, whereas peripheralist theories propose that physiological arousal precedes cognitive processes. Three studies examined this issue regarding threat and challenge responses to potential stress. Study 1 supported cognitive appraisal theory by demonstrating that threat and challenge cognitive appraisals and physiological responses could be elicited experimentally by manipulating instructional set. Studies 2 and 3, in contrast, found that manipulations of physiological response patterns consistent with challenge and threat did not result in corresponding changes in cognitive appraisal. Appraisals in Study 3, however, were related to subjective pain independent of the physiological manipulation. These studies suggest a central role for cognitive appraisal processes in elicitation of threat and challenge responses to potentially stressful situations.

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.

Lonely hearts: Psychological perspectives on loneliness.

Abstract Loneliness is a complex set of feelings encompassing reactions to the absence of intimate and social needs. Although transient for some individuals, loneliness can be a chronic state for others. We review the developmental, social, personality, clinical, and counseling psychology literatures on loneliness with an emphasis on recent empirical findings. Chronic feelings of loneliness appear to have roots in childhood and early attachment processes. Chronically lonely individuals are more likely to be high in negative affectivity, act in a socially withdrawn fashion, lack trust in self and others, feel little control over success or failure, and generally be dissatisfied with their relationships compared to nonlonely individuals. Loneliness has also been associated with a variety of individual differences including depression, hostility, pessimism, social withdrawal, alienation, shyness, and low positive affect; loneliness is also a concomitant of more severe disorders, such as clinical depression, borderline personality, and schizophrenia. Although loneliness affects a large number of individuals and is associated with numerous negative outcomes, relatively few investigations have examined the efficacy of treatments aimed at alleviating or preventing loneliness. Several investigations raise the possibility of treating loneliness, but the absence of appropriate comparison groups casts doubt on the efficacy of many of these treatments. Correlational studies also suggest that one close friend or romantic partner may be sufficient to buffer those at risk for loneliness. Research on causal processes is sparse, however, and more research is needed to delineate which factors are antecedents and which are consequences of loneliness.

Autonomic, Neuroendocrine, and Immune Responses to Psychological Stress: The Reactivity Hypothesisa

Abstract: We examined the effects of brief psychological stressors on cardiovascular, neuroendocrine, and cellular immune response in 22 older women to investigate the common effects of stress across systems. Results revealed that psychological stressors heightened cardiac sympathetic activation, elevated plasma catecholamine concentrations, and affected the cellular immune response (ps < 0.05). In a replication and extension, 27 women caring for a spouse with a progressive dementia (high chronic stress) and 37 controls category matched for age and family income (low chronic stress) performed the 12‐min laboratory stressor. Measures were taken before (low acute stress) and immediately following (high acute stress) exposure to the laboratory stressors as well as 30 min after termination of the stressor (recovery period). Acute stress again heightened cardiac sympathetic activation, elevated plasma catecholamine concentrations, and affected cellular immune responses (ps < 0.05), whereas chronic stress was associated with higher reports of negative affect, enhanced cardiac sympathetic activation, elevated blood pressure and plasma levels of ACTH, and diminished production of interleukin‐1β (ps < 0.05). Correlational analyses in both studies further suggested that individuals who showed the greatest stress‐related changes in HPA activation also exhibited the greatest diminution in cellular immune response.

Do Lonely Days Invade the Nights? Potential Social Modulation of Sleep Efficiency

Loneliness predicts morbidity and mortality from broad-based causes, but the reasons for this effect remain unclear. Few differences in traditional health behaviors (e.g., smoking, exercise, nutrition) have been found to differentiate lonely and nonlonely individuals. We present evidence that a prototypic restorative behavior—sleep—does make such a differentiation, not through differences in time in bed or in sleep duration, but through differences in efficacy: In the study we report here, lonely individuals evinced poorer sleep efficiency and more time awake after sleep onset than nonlonely individuals. These results, which were observed in controlled laboratory conditions and were found to generalize to the home, suggest that lonely individuals may be less resilient than nonlonely individuals in part because they sleep more poorly. These results also raise the possibility that social factors such as loneliness not only may influence the selection of health behaviors but also may modulate the salubrity of restorative behaviors.

Mapping cognitive structures and processes through verbal content: the thought-listing technique.

Open-ended cognitive assessment techniques have helped illuminate the cognitive structures and processes underlying various clinical problems. The authors review a specific open-ended protocol analysis for assessing cognitive structures and processes--the thought-listing technique. They begin with a brief description of this technique and its validity, limitations, and potential clinical use. They then review representative research using the thought-listing technique in studies of psychopathology and psychotherapy. They conclude with a discussion of new and potentially useful methods (e.g., adjusted ratio of clustering scores, multidimensional scaling, implicit memory measures) for mapping cognitive representations and coping processes on the basis of data from thought listings in clinical and counseling psychology.

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.

New ambulatory impedance cardiograph validated against the Minnesota Impedance Cardiograph

The validity and reliability of a new ambulatory impedance cardiograph (AZCG) was tested against the Minnesota Impedance Cardiograph (ZCG) during rest, orthostasis, and mental stress. Impedance cardiography allows noninvasive assessment of stroke volume, cardiac output, and systolic time intervals. A reliable ambulatory device would allow studies outside the lab. The devices were compared at two sites in healthy subjects. In both studies, the AZCG tracked changes across conditions closely with the ZCG (all Period x Device interactions were nonsignificant). Pearson rs, were .65 to .93, random intraclass correlation coefficients ranged from .80 to .98, indicating high degrees of shared measurement variance, and Cronbachs alpha indicated very good internal reliabilities (.91 to .99). Relative to the ZCG, the new AZCG appears to provide valid and reliable estimates of cardiac function at rest and during behavioral challenges in the lab.

Stress-related immune changes in middle-aged and older women: 1-year consistency of individual differences.

This study reviews prior research and reports longer-term consistency of stress-related immune variables in middle-aged and older women who performed mental math and speech tasks 2 times 1 year apart. Leukocyte subsets, mitogen-induced lymphocyte proliferation, and natural killer cell activity were measured at baseline, after tasks, and after 30-min recovery. Epstein-Barr virus (EBV) antibody titers were assessed at baseline. Pearson coefficients and standardized maximum-likelihood estimates of year-to-year covariances for leukocyte subsets and EBV titers showed moderately high to high baseline and posttask consistency and lower recovery consistency; consistency for other functional immune assays and reactivity scores for all variables was moderate to low. Results support longitudinal study of psychosocial context effects on tonic immune function and posttask scores.