Previous research has linked perceived social isolation (loneliness) to reduced antiviral immunity, but the immunologic effects of the objective social isolation imposed by pandemic "shelter in place" (SIP) policies is unknown. We assessed the immunologic impact of SIP by relocating 21 adult male rhesus macaques from 2,000-m2 field cage communities of 70 to 132 other macaques to 2 wk of individual housing in indoor shelters. SIP was associated with 30% to 50% reductions in all circulating immune cell populations (lymphocytes, monocytes, and granulocytes), down-regulation of Type I interferon (IFN) antiviral gene expression, and a relative up-regulation of CD16- classical monocytes. These effects emerged within the first 48 h of SIP, persisted for at least 2 wk, and abated within 4 wk of return to social housing. A subsequent round of SIP in the presence of a novel juvenile macaque showed comparable reductions in circulating immune cell populations but reversal of Type I IFN reductions and classical monocyte increases observed during individual SIP. Analyses of lymph node tissues showed parallel up-regulation of Type I IFN genes and enhanced control of viral gene expression during juvenile-partnered SIP compared to isolated SIP. These results identify a significant adverse effect of SIP social isolation on antiviral immune regulation in both circulating immune cells and lymphoid tissues, and they suggest a potential behavioral strategy for ameliorating gene regulatory impacts (but not immune cell declines) by promoting prosocial engagement during SIP.

Exposure to a major traumatic stressor increases the odds of negative mental health and maladaptive behavioral outcomes not only for victims but also for 1st responders and health care professionals who are exposed to the aftermath. This study investigates the extent to which psychological resilience acts as either a Protective (i.e., vaccine-like) or an Ameliorative (i.e., antibiotic-like) factor to reduce the deleterious mental health outcomes associated with exposure to a major stressor. To do so, this pilot study focused on the understudied population of military combat medics, who are exposed to both stressors associated with direct combat and with providing intense battlefield trauma care. Military combat medics who were identified as having deployed to Iraq or Afghanistan shortly after baseline measurements of posttraumatic stress disorder, depression, and aggressive behavioral tendencies and returned from deployment prior to the follow-up assessment (protective model) were compared to those who returned from deployment in Iraq or Afghanistan shortly before the baseline measurements and were not deployed again prior to the follow-up assessments (ameliorative model). Data were collected on combat experiences to equate the stressor for these 2 samples, and a propensity score matching technique was used to ensure that the 2 samples were similar. The findings provide support for both the protective and the ameliorative models of psychological resilience. Results are discussed in terms of the potential benefits of resilience in mental health programs. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Objectives: Integration into social networks reduces stress during adverse life events and improves coping with disability in late life. The aim was to investigate whether social network closure (frequent contact among ties) and balance (positive contact among ties) are associated with perceived stress. We expect lowest stress for older adults with highly closed and balanced networks. Method: Panel data on self-reported egocentric networks stem from the population-based Chicago Health, Aging, and Social Relations Study. Five waves were collected between 2002 and 2006, with 708 observations from 160 participants aged 50-68 years at baseline. Data include information on the participants' social relationships, that is, interaction frequency and relationship quality, for ego-alter ties and alter-alter ties, and participants' perceived stress. The analytical strategy used fixed- and random-effects models. Results: Participants reporting the highest number of balanced relationships (positive ties among alters) experience least stress. This effect holds independently of sociodemographic confounders, loneliness, and network size. Discussion: The absence of a stress-reducing effect from network closure suggests that balance matters more. Future research would benefit from considering balance when examining the characteristics of social networks that impinge on mental health outcomes in older adults.

The Distress and Risk Assessment Method (DRAM) predicts poor outcomes in spine, hip, and knee surgery. Unlike other areas of orthopedic surgery, DRAM scores are not predictive of lower postoperative patient-reported outcomes after arthroscopic rotator cuff repair (RCR).As concerns for opioid dependence and abuse grow, the purpose of this study was to analyze the correlation between preoperative DRAM scores, modified Zung scores, and postoperative narcotic use in patients who underwent arthroscopic RCR.This prospective cohort study identified and enrolled patients >18 years of age with full-thickness rotator cuff tears at a single institution. Patients with prior shoulder surgery, greater than 1-tendon RCR, and preoperative narcotic use were excluded. One-hundred and fifty patients were enrolled, with 114 (76%) completing all preoperative and postoperative questionnaires. Preoperative DRAM scores were collected from every patient. Postoperative narcotic use was evaluated via survey and converted to total morphine equivalents.Increased preoperative DRAM scores predicted higher postoperative morphine equivalent units (P = .002, r = 0.29). When dividing patients into those <17 or ≥17 on the modified Zung score, 44 of 114 (39%) met criteria for “at risk or depressed.” This group showed a statistically significant trend toward higher postoperative morphine equivalent unit intake (P = .004).Baseline psychological distress (DRAM) can predict narcotic requirements after RCR and serve as a powerful tool to identify patients at risk for increased narcotics requirements postoperatively. In our cohort, 39% of patients showed evidence of baseline depression, which highlights a potential role of the modified Zung score to identify patients in need of preoperative psychological counseling.

Humans are social animals that experience intense suffering when they perceive a lack of social connection. Modern societies are experiencing an epidemic of loneliness. Although the experience of loneliness is universally human, some people report experiencing greater loneliness than others. Loneliness is more strongly associated with mortality than obesity, emphasizing the need to understand the nature of the relationship between loneliness and health. Although it is intuitive that circumstantial factors such as marital status and age influence loneliness, there is also compelling evidence of a genetic predisposition toward loneliness. To better understand the genetic architecture of loneliness and its relationship with associated outcomes, we extended the genome-wide association study meta-analysis of loneliness to 511280 subjects, and detect 19 significant genetic variants from 16 loci, including four novel loci, as well as 58 significantly associated genes. We investigated the genetic overlap with a wide range of physical and mental health traits by computing genetic correlations and by building loneliness polygenic scores in an independent sample of 18498 individuals with EHR data to conduct a PheWAS with. A genetic predisposition toward loneliness was associated with cardiovascular, psychiatric, and metabolic disorders and triglycerides and high-density lipoproteins. Mendelian randomization analyses showed evidence of a causal, increasing, the effect of both BMI and body fat on loneliness. Our results provide a framework for future studies of the genetic basis of loneliness and its relationship to mental and physical health.

Loneliness is a negative and distressing emotional state that arises from a discrepancy between one’s desired and achieved levels of social connectedness. The evolutionary theory of loneliness (ETL) posits that experiencing loneliness is an inherited adaptation that signals that salutary social relations are endangered or damaged and prompts people to reconnect to significant others. The basic tenets of the ETL has led researchers to examine the genetic underpinnings of loneliness. The current review provides an updated overview of genetic studies on loneliness and discusses the importance of genetic research for the ETL. The most recent studies suggest that the many genes that contribute to a small degree to differences in loneliness partially overlap with genes that contribute to neuroticism, but not with depression. In addition, the genetic studies discussed in this review show that genes are unlikely to have a direct effect on loneliness. Instead, environmental factors determine in a dynamic fashion how genes that contribute to loneliness are expressed. Future research on epigenetic processes, such as DNA methylation, can further elucidate the dynamic interplay between genes and the environment and how this interplay contributes to loneliness.

Loneliness is a heritable trait that accompanies multiple disorders. The association between loneliness and mental health indices may partly be due to inherited biological factors. We constructed polygenic scores for 27 traits related to behavior, cognition and mental health and tested their prediction for self-reported loneliness in a population-based sample of 8798 Dutch individuals. Polygenic scores for major depressive disorder (MDD), schizophrenia and bipolar disorder were significantly associated with loneliness. Of the Big Five personality dimensions, polygenic scores for neuroticism and conscientiousness also significantly predicted loneliness, as did the polygenic scores for subjective well-being, tiredness and self-rated health. When including all polygenic scores simultaneously into one model, only 2 major depression polygenic scores remained as significant predictors of loneliness. When controlling only for these 2 MDD polygenic scores, only neuroticism and schizophrenia remain significant. The total variation explained by all polygenic scores collectively was 1.7%. The association between the propensity to feel lonely and the susceptibility to psychiatric disorders thus pointed to a shared genetic etiology. The predictive power of polygenic scores will increase as the power of the genome-wide association studies on which they are based increases and may lead to clinically useful polygenic scores that can inform on the genetic predisposition to loneliness and mental health.

With the rise of online social networking, social relationships are increasingly developed and maintained in a digital domain. Drawing conclusions about the impact of the digital world on loneliness is difficult because there are contradictory findings, and cross-sectional studies dominate the literature, making causation difficult to establish. In this review, we present our theoretical model and propose that there is a bidirectional and dynamic relationship between loneliness and social Internet use. When the Internet is used as a way station on the route to enhancing existing relationships and forging new social connections, it is a useful tool for reducing loneliness. But when social technologies are used to escape the social world and withdraw from the "social pain" of interaction, feelings of loneliness are increased. We propose that loneliness is also a determinant of how people interact with the digital world. Lonely people express a preference for using the Internet for social interaction and are more likely to use the Internet in a way that displaces time spent in offline social activities. This suggests that lonely people may need support with their social Internet use so that they employ it in a way that enhances existing friendships and/or to forge new ones.

Anthropomorphism, the attribution of distinctively human mental characteristics to nonhuman animals and objects, illustrates the human propensity for extending social cognition beyond typical social targets. Yet, its processing components remain challenging to study because they are typically all engaged simultaneously. Across one pilot study and one focal study, we tested three rare people with basolateral amygdala lesions to dissociate two specific processing components: those triggered by attention to social cues (e.g., seeing a face) and those triggered by endogenous semantic knowledge (e.g., imbuing a machine with animacy). A pilot study demonstrated that, like neurologically intact control group participants, the three amygdala-damaged participants produced anthropomorphic descriptions for highly socially salient stimuli but not for stimuli lacking clear social cues. A focal study found that the three amygdala participants could anthropomorphize animate and living entities normally, but anthropomorphized inanimate stimuli less than control participants. Our findings suggest that the amygdala contributes to how we anthropomorphize stimuli that are not explicitly social.

Imagine a condition that makes a person irritable, depressed, and self-centred, and is associated with a 26% increase in the risk of premature mortality. Imagine too that in industrialised countries around a third of people are affected by this condition, with one person in 12 affected severely, and that these proportions are increasing. Income, education, sex, and ethnicity are not protective, and the condition is contagious. The effects of the condition are not attributable to some peculiarity of the character of a subset of individuals, they are a result of the condition affecting ordinary people. Such a condition exists—loneliness.1Cacioppo JT Cacioppo S Capitanio JP Cole SW The neuroendocrinology of social isolation.Annu Rev Psychol. 2015; 66: 733-767Crossref PubMed Scopus (433) Google Scholar, 2Miller G Scoial neuroscience. Why loneliness is hazardous to your health.Science. 2011; 331: 138-140Crossref PubMed Scopus (64) Google Scholar, 3Holt-Lunstad J Smith TB Loneliness and social isolation as risk factors for CVD: implications for evidence-based patient care and scientific inquiry.Heart. 2016; 102: 987-989Crossref PubMed Scopus (105) Google Scholar Loneliness is often stigmatised, trivialised, or ignored, but—with the rapidly growing number of older adults in industrialised countries, the increased likelihood of premature mortality, and the deleterious effects of loneliness that have been identified in animal models and human longitudinal investigations—loneliness is emerging as a public health problem.4Murthy V Work and the loneliness epidemic. Harvard Business Review (Brighton).https://hbr.org/cover-story/2017/09/work-and-the-loneliness-epidemicDate: Sept 28, 2017Google Scholar Physicians are encountering this condition, but most do not have the information needed to deal effectively with loneliness in their patients. Loneliness has been associated with objective social isolation, depression, introversion, or poor social skills. However, studies have shown these characterisations are incorrect, and that loneliness is a unique condition in which an individual perceives himself or herself to be socially isolated even when among other people. Furthermore, human longitudinal studies and animal models indicate that the deleterious effects of loneliness are not attributable to some peculiarity of individuals who are lonely, instead they are due to the effects of loneliness on ordinary people.1Cacioppo JT Cacioppo S Capitanio JP Cole SW The neuroendocrinology of social isolation.Annu Rev Psychol. 2015; 66: 733-767Crossref PubMed Scopus (433) Google Scholar, 5Cacioppo S Capitanio JP Cacioppo JT Toward a neurology of loneliness.Psychol Bull. 2014; 140: 1464-1504Crossref PubMed Scopus (270) Google Scholar, 6Cole SW Capitanio JP Chun K Arevalo JM Ma J Cacioppo JT Myeloid differentiation architecture of leukocyte transcriptome dynamics in perceived social isolation.Proc Natl Acad Sci U S A. 2015; 112: 15142-15147Crossref PubMed Scopus (154) Google Scholar Quick and valid measures exist that can diagnose if a patient has abnormally high levels of loneliness,7Hughes ME Waite LJ Hawkley LC Cacioppo JT A short scale for measuring loneliness in large surveys: results from two population-based studies.Res Aging. 2004; 26: 655-672Crossref PubMed Scopus (1925) Google Scholar and although so-called common sense treatments (eg, social skills training, and provisions for social support and social contact) have proven ineffective,8Masi CM Chen HY Hawkley LC Cacioppo JT A meta-analysis of interventions to reduce loneliness.Pers Soc Psychol Rev. 2011; 15: 219-266Crossref PubMed Scopus (914) Google Scholar the availability of community programmes, behavioural interventions, and online resources is increasing to address the problem of loneliness. Loneliness is a public health problem that can be largely solved in our lifetime but doing so will require the full engagement and support of the medical community. The physical health and mental health of a growing number of afflicted individuals and their families and friends are at stake. We declare no competing interests. Beware the medicalisation of lonelinessLoneliness was recently described in The Lancet as a public health problem that needs to be solved by the medical community (Feb 3, p 426).1 We believe that the medicalisation of loneliness in this way is damaging, especially at a time when the issue is making its way into public understanding. Full-Text PDF

Persuasion, a prevalent form of social influence in humans, refers to an active attempt to change a person's attitudes, beliefs, or behavior. There is a growing literature on the neural correlates of persuasion. As is often the case in an emerging literature, however, there are a number of questions, concerns, and alternative interpretations that can be raised about the research and interpretations. We provide a critical review of the research, noting potential problems and issues that warrant attention to move the field forward. Among the recommendations are greater integration of neuroimaging approaches with existing behavioral theories and methods on the information processes (cognitive and affective) underlying persuasion, and moving beyond solely correlative approaches for specifying underlying neural mechanisms. Work in this area has the potential to contribute to our understanding of brain-behavior relationships as well as to advance our understanding of persuasion and social influence more generally.

According to the differential reactivity hypothesis, lonely individuals respond differently to their environment compared to nonlonely individuals, which may sustain their loneliness levels. However, this interesting hypothesis has not yet been explored in daily life: Do lonely individuals feel lonely all the time, or do they feel more or less lonely in specific social contexts? The main aim of the present study was to test the differential reactivity hypothesis in daily life by examining in three samples whether trait levels of loneliness affected the levels of state loneliness in different social contexts. We used baseline questionnaires to measure trait loneliness and the Experience Sampling Method to collect data on state loneliness, in early adolescents (N=269, M-age=14.49, 59% female) and late adolescents (N=223, M-age=19.60, 91% female) from the Netherlands and late adolescents from the United States (N=126, M-age=19.20, 51% female). Results provided evidence for the differential reactivity hypothesis in the total sample, as high lonely adolescents experienced higher levels of state loneliness in situations in which they were alone than low lonely adolescents, but also benefited more from being with intimate company than low lonely adolescents. In sum, the present study provided evidence for the differential reactivity hypothesis and showed that the experience of loneliness in daily life was remarkably similar across age and culture. Our findings provide important insights into the daily experiences of trait lonely people, which may provide starting points for interventions.

Loneliness is thought to serve as an adaptive signal indicating the need to repair or replace salutary social connections. Accordingly, loneliness may influence preferences for interpersonal distance. If loneliness simply motivates a desire to socially reconnect, then loneliness may be associated with a preference for smaller interpersonal distances. According to the evolutionary model of loneliness, however, loneliness also signals an inadequacy of mutual aid and protection, augmenting self-preservation motives. If loneliness both increases the motivation to reconnect and increases the motivation for self-protection, then the resulting approach-avoidance conflict should produce a preference for larger interpersonal distance, at least within intimate (i.e., proximal) space. Here, we report two survey-based studies of participants' preferences for interpersonal distance to distinguish between these competing hypotheses. In Study 1 (N = 175), loneliness predicted preferences for larger interpersonal distance within intimate space net gender, objective social isolation, anxiety, depressive symptomatology, and marital status. In Study 2 (N = 405), we replicated these results, and mediation analyses indicated that measures of social closeness could not adequately explain our findings. These studies provide compelling evidence that loneliness predicts preferences for larger interpersonal distance within intimate space, consistent with predictions from the evolutionary model of loneliness.