Loneliness and attention to social threat in young adults: Findings from an eye tracker study

Ambiguity potentiates effects of loneliness on feelings of rejection

For social species, having strong and high-quality social relationships is an important safety cue. Loneliness occurs when an individual perceives they have insufficient relationships resulting in feelings of lack of safety. States of perceived unsafety are linked to an increased tendency to construe ambiguous information - information lacking a unique clear interpretation - as threatening. Here, we explore whether the ambiguity of social cues of interpersonal rejection moderates effects of loneliness on feelings of rejection while undergoing social exclusion. Data were collected in 2021; 144 adults completed a progressive social exclusion paradigm where they were randomly assigned to be equally included, excluded, or over-included. Social exclusion/inclusion cues became more pronounced over the course of multiple rounds of a ball-tossing game (Cyberball) resulting in a scenario where ambiguity was highest in earlier rounds and decreased over time. Participants reported feelings of loneliness prior to the task and feelings of rejection throughout the task. Results demonstrated that higher loneliness predicted increased feelings of rejection regardless of exclusion condition. Notably, this positive relationship was strongest during earlier rounds when social cues were most ambiguous. These findings contribute to our understanding of how loneliness modulates social perception to enable organisms to adequately adapt to changing circumstances.

The lonely brain: Aligning theories of loneliness with data from neuroimaging studies

Although loneliness is an unpleasant subjective experience associated with negative consequences, decades of research suggest loneliness is accompanied by adaptive cognitive changes that promote self-preservation and attempts for social reconnection. This review summarizes theoretical accounts that elaborate how loneliness alters attention and social information processing, then reviews whether findings from functional magnetic resonance imaging (fMRI) studies align with these hypothesized effects. We first examined the hypothesis that loneliness should increase general attention to monitor for potential environmental threats. Findings from resting-state studies suggested that loneliness corresponds to greater baseline activity in attention-related regions. Next, we examined the hypothesis that loneliness heightens sensitivity to the social world to protect against social threats and motivate reconnection. Here, studies showed sensitivity toward negative social information increased, whereas sensitivity toward positive social information was stimulus dependent (e.g., strangers, close others). Finally, we examined the hypothesis that loneliness enhances mentalizing to better predict social situations. Although many studies support this hypothesis, the research here is limited. However, studies do find that lonely individuals show idiosyncratic processing of the self and others. To conclude, we lay out future directions addressing some shortcomings of current fMRI studies of loneliness, and provide additional avenues to expand our knowledge of the "lonely brain."

The perception of eye contact is associated with men's need to belong, self-esteem, and loneliness

The present study (N =  367) investigated the association of the cone of direct gaze (CoDG; a range within which slightly averted gaze is accepted as direct gaze) width with the need to belong (NTB) and the possible further influence of NTB on self-esteem and loneliness. Results showed that: (i) men's CoDG width predicted the NTB, self-esteem, and loneliness; (ii) men's narrow CoDG predicted high loneliness via a high NTB and low self-esteem; (iii) a narrow CoDG was associated with low self-esteem via high loneliness only in high-NTB men. Among women, the CoDG width was not associated with the NTB, self-esteem, and loneliness. The findings are discussed considering the formation and maintenance of relationships together with gender differences.

Loneliness trajectories and psychological distress in youth: Longitudinal evidence from a population-based sample

This pre-registered secondary analysis aimed to examine distinct longitudinal loneliness trajectories in youth and whether these trajectories were associated with psychological distress at final follow-up in the UK Household Longitudinal Study. Participants (N = 827, 55.1% female, Time 1: M ± SD = 16.50 ± 0.50 years) provided data during Waves 9, 10 and 11. K-means longitudinal clustering analysis was used to identify clusters of participants with distinct loneliness trajectories across measurement waves. We identified four clusters demonstrating distinct trajectories of loneliness: stable low (40.7%), stable high (20.6%), moderate decreasing (19.6%) and low increasing (19.1%). Compared to 'stable low loneliness', 'stable high' and 'low increasing' loneliness clusters were significantly associated with psychological distress at Wave 11 following adjustment for sex, ethnicity, parent's highest educational achievement and Wave 9 psychological distress. The current study offers an important contribution to the literature on patterns of youth loneliness and mental health consequences.

The Impact of Loneliness and Social Anxiety on Casual Social Contacts

Introduction In the wake of the COVID-19 pandemic, loneliness and social isolation have become major public health crises. Loneliness has reached epidemic levels and negatively impacts both health and quality of life. "Casual contacts" is a developing line of research that may hold promise in stemming the current crisis. Casual contacts refer to interactions and relationships with people who are neither family nor friends. Our objectives are to (a) document the impact of casual contacts on community-based adults (Studies 1 and 2) and (b) study the impact of loneliness (Studies 1 and 2) and social anxiety (Study 2) on responses to casual contact. Based on prior studies, we expect to find that casual contacts have a generally positive impact on mood. However, the association of both loneliness and social anxiety with hypervigilance to social threat leads to the broad hypothesis that individuals with each of these conditions would be more likely to respond negatively to casual contacts than would others without those conditions. Method This correlational research recruited convenience samples of English-speaking adults living in the United States, using the online platform Survey Monkey. There were no selection criteria beyond (a) language and location and (b) the sample being generally balanced for age and gender. Partial correlation and analysis of covariance were used to examine the association of loneliness and social anxiety with feeling worse after casual contacts, while controlling for age, gender, household size, household income, and size of town. Because the current study examines a novel area, individual differences that affect how people experience casual contacts, we ran two studies enabling us to examine whether the results replicated. In total, we surveyed 546 community-dwelling adults about their casual contacts, 174 in Study 1 and 372 in Study 2. Data cleaning was used to minimize/eliminate meaningless and random answers resulting in a final total study sample of 393 participants: 123 in Study 1 and 270 in Study 2. Results The results indicate that casual contacts are common, with fewer than 4% having neither verbal nor electronic contact with an acquaintance weekly, and typically have a positive impact (Study 1 and Study 2). Nevertheless, a significant minority of casual contacts result in negative experiences, which is more probable among respondents who were lonely (Study 1 and Study 2) and/or had higher levels of social anxiety (Study 2). Exploratory analyses showed that both loneliness and social anxiety are linked to feeling worse for longer periods of time after casual contacts and that positive feelings tend to dissipate more rapidly for those with higher loneliness scores (Study 2).  Conclusions These results indicate that clinicians developing interventions that involve casual contacts must consider how to do so safely and effectively for those with a higher degree of loneliness and/or social anxiety.

Exploring the relationship between resilience and internet addiction in Chinese college students: The mediating roles of life satisfaction and loneliness

Internet addiction is of great impact on college students' academic performance, life quality and mental health. Although it's well documented the association between resilience and Internet addiction among college students, the mechanism underlying it are not well acknowledged. The study applied resilience scale, the Chinese Internet Addiction Scale, Satisfaction with Life Scale and the third edition of the UCLA Loneliness Scale to explore the mechanism of action between resilience and Internet addiction in college students by applied questionnaire investigation. A total of 813 college students (321 male, Mean age = 22.55) participated in the study. We found resilience and life satisfaction of college students were negatively correlated with Internet addiction (β = -0.85, t = -21.35, p < 0.001; β = -0.08, t = -2.23, p < 0.05), while loneliness was positively correlated with Internet addiction (β = 0.17, t = 7.42, p < 0.01). Furthermore, mediating analyses showed life satisfaction and loneliness played mediating role in the relationship between resilience and Internet addiction (β = -0.90, t = -58.76, p < 0.001). Measures such as strengthening the construction of college students' mental health courses to improve their resilience and life satisfaction, and providing rich community activities to reduce college students' loneliness have been put forward to reduce college students' Internet addiction.

The relationship between loneliness and the experiences of everyday stress and stressor-related emotion

Loneliness influences how people experience and respond to stressors, which may account for its role as a risk factor for morbidity and mortality. The present study was motivated by emerging evidence that affective responses to minor daily events have long-term implications for health and well-being. Specifically, we evaluated how individual differences in loneliness relate to the frequency of everyday stressors and stressor-related negative emotions. A diverse community sample of 255 adults (age 25-65 years) completed ecological momentary assessments (EMA), during which they reported recent stressors and current negative affect (NA) five times a day for 14 days. Multilevel logistic analyses indicated that there was a quadratic association between loneliness and likelihood of reporting stressors, controlling for demographics, social isolation, depressive symptoms, and context (current activities, current location). Multilevel regression indicated that loneliness was unrelated to the concurrent effect of stressors on NA but significantly larger lagged stressor effects were observed among individuals in the low and high ranges of loneliness. These findings suggest that individuals with high levels of loneliness are more likely to experience everyday stressors and have prolonged emotional responses following stressors.

Can we dissociate hypervigilance to social threats from altered perceptual decision-making processes in lonely individuals? An exploration with Drift Diffusion Modeling and event-related potentials

It has been hypothesized that lonely individuals demonstrate hypervigilance toward social threats. However, recent studies have raised doubts about the reliability of tasks commonly used to measure attentional biases toward threats. Two alternative approaches have been suggested to overcome the limitations of traditional analysis of attentional bias. First, the neurophysiological indicators of orienting to threats were shown to have superior psychometric characteristics compared to overt measures of behavioral performance. The second approach involves utilizing computational modeling to isolate latent components corresponding to specific cognitive mechanisms from observable data. To test the usefulness of these approaches in loneliness research, we analyzed behavioral and electroencephalographic (EEG) data from 26 lonely and 26 non-lonely participants who performed a dot-probe task using a computational modeling approach. We applied the Drift Diffusion Model (DDM) and extracted N2pc-an event-related potential that serves as an indicator of spatial attention. No evidence for social threat hypervigilance has been found in DDM parameters nor in N2pc characteristics in the current study. However, we did observe decreased drift rate and increased variability in drift rate between trials within the lonely group, indicating reduced efficiency in perceptual decision-making among lonely individuals. These effects were not detected using standard behavioral measures used in the dot-probe paradigm. Given that DDM indicators were sensitive to differences in perceptual discrimination between the two groups, even when no overt differences were found in standard behavioral measures, it may be postulated that computational approaches offer a more comprehensive understanding of cognitive processes.

Loneliness and depression: bidirectional mendelian randomization analyses using data from three large genome-wide association studies

Major depression (MD) is a serious psychiatric illness afflicting nearly 5% of the world's population. A large correlational literature suggests that loneliness is a prospective risk factor for MD; correlational assocations of this nature may be confounded for a variety of reasons. This report uses Mendelian Randomization (MR) to examine potentially causal associations between loneliness and MD. We report on analyses using summary statistics from three large genome wide association studies (GWAS). MR analyses were conducted using three independent sources of GWAS summary statistics. In the first set of analyses, we used available summary statistics from an extant GWAS of loneliness to predict MD risk. We used two sources of outcome data: the Psychiatric Genomics Consortium (PGC) meta-analysis of MD (PGC-MD; N = 142,646) and the Million Veteran Program (MVP-MD; N = 250,215). Finally, we reversed analyses using data from the MVP and PGC samples to identify risk variants for MD and used loneliness outcome data from UK Biobank. We find robust evidence for a bidirectional causal relationship between loneliness and MD, including between loneliness, depression cases status, and a continuous measure of depressive symptoms. The estimates remained significant across several sensitivity analyses, including models that account for horizontal pleiotropy. This paper provides the first genetically-informed evidence that reducing loneliness may play a causal role in decreasing risk for depressive illness, and these findings support efforts to reduce loneliness in order to prevent or ameliorate MD. Discussion focuses on the public health significance of these findings, especially in light of the SARS-CoV-2 pandemic.

Association of loneliness and grey matter volume in the dorsolateral prefrontal cortex: the mediating role of interpersonal self-support traits

As a social and public health concern, loneliness is associated with an abundance of negative life outcomes such as depressive symptomatology, mortality, and sleep disturbance. Nevertheless, the neural basis underlying loneliness remains elusive; in addition, previous neuroimaging studies about loneliness mainly focused on the elderly and were limited by small sample sizes. Here, utilizing the voxel-based morphometry (VBM) approach via structural magnetic resonance imaging, we investigated the association between brain GMV and loneliness in 462 young adults (67.7% females, age = 18.59 ± 1.14 years). Results from whole-brain VBM analyses revealed that individuals with higher loneliness tended to have greater GMV in the right dorsolateral prefrontal cortex (DLPFC), which was thought to be associated with emotional regulation deficits and executive dysfunction. Importantly, the GMV-based predictive models (a machine-learning method) demonstrated that the correlation between loneliness and GMV in the DLPFC was robust. Further, interpersonal self-support traits (ISS), a Chinese indigenous personality construct and pivotal personality factor for resisting negative life outcomes, mediated the relationship between the GMV in the right DLPFC and loneliness. Taken together, the present study reveals that the GMV in right DLPFC acts as an underlying neurostructural correlate of loneliness in the healthy brain, and further provides a brain-personality-symptom pathway for protection against loneliness in which GMV of DLPFC affects loneliness through ISS traits. Future intervention procedures aiming to decrease loneliness and enhance mental health levels among young adults should be developed through improving interpersonal relationships such as social skills training.

Social Withdrawal, Loneliness, and Health in Schizophrenia: Psychological and Neural Mechanisms

BACKGROUND AND HYPOTHESIS

Some of the most debilitating aspects of schizophrenia and other serious mental illnesses (SMI) are the impairments in social perception, motivation, and behavior that frequently accompany these conditions. These impairments may ultimately lead to chronic social disconnection (ie, social withdrawal, objective isolation, and perceived social isolation or loneliness), which may contribute to the poor cardiometabolic health and early mortality commonly observed in SMI. However, the psychological and neurobiological mechanisms underlying relationships between impairments in social perception and motivation and social isolation and loneliness in SMI remain incompletely understood.

STUDY DESIGN

A narrative, selective review of studies on social withdrawal, isolation, loneliness, and health in SMI.

STUDY RESULTS

We describe some of what is known and hypothesized about the psychological and neurobiological mechanisms of social disconnection in the general population, and how these mechanisms may contribute to social isolation and loneliness, and their consequences, in individuals with SMI.

CONCLUSIONS

A synthesis of evolutionary and cognitive theories with the "social homeostasis" model of social isolation and loneliness represents one testable framework for understanding the dynamic cognitive and biological correlates, as well as the health consequences, of social disconnection in SMI. The development of such an understanding may provide the basis for novel approaches for preventing or treating both functional disability and poor physical health that diminish the quality and length of life for many individuals with these conditions.

Do loneliness and social exclusion breed paranoia? An experience sampling investigation across the psychosis continuum

Background

The role of loneliness and social exclusion in the development of paranoia is largely unexplored. Negative affect may mediate potential associations between these factors. We investigated the temporal relationships of daily-life loneliness, felt social exclusion, negative affect, and paranoia across the psychosis continuum.

Method

Seventy-five participants, including 29 individuals with a diagnosis of non-affective psychosis, 20 first-degree relatives, and 26 controls used an Experience Sampling Method (ESM) app to capture the fluctuations in loneliness, feelings of social exclusion, paranoia, and negative affect across a 1-week period. Data were analysed with multilevel regression analyses.

Results

In all groups, loneliness and feelings of social exclusion were independent predictors of paranoia over time (b = 0.05, p < .001 and b = 0.04, p < .05, respectively). Negative affect predicted paranoia (b = 0.17, p < .001) and partially mediated the associations between loneliness, social exclusion, and paranoia. It also predicted loneliness (b = 0.15, p < .0001), but not social exclusion (b = 0.04, p = .21) over time. Paranoia predicted social exclusion over time, with more pronounced effects in controls (b = 0.43) than patients (b = 0.19; relatives: b = 0.17); but not loneliness (b = 0.08, p = .16).

Conclusion

Paranoia and negative affect worsen in all groups following feelings of loneliness and social exclusion. This highlights the importance of a sense of belonging and being included for mental well-being. Loneliness, feeling socially excluded, and negative affect were independent predictors of paranoid thinking, suggesting they represent useful targets in its treatment.

Perceived Parental Support and Psychological Control, DNA Methylation, and Loneliness: Longitudinal Associations Across Early Adolescence

A broad range of factors have been associated with the development of adolescent loneliness. In the family context, a lack of parental support and high levels of parental psychological control have systematically been linked to loneliness. On the biological level, DNA methylation (which is an epigenetic process that suppresses gene expression) is believed to play a role in the development of loneliness. Specifically, high levels of DNA methylation in genes that play an important role in the functioning of the human stress response system are believed to elevate the risk of loneliness. Moreover, DNA methylation levels in these stress-related genes can be influenced by stressful environmental factors, suggesting a potential mediating role of DNA methylation in the association between parenting behaviors and loneliness. The current 3-year longitudinal study is the first study to examine the potential bidirectional longitudinal associations between loneliness, DNA methylation in stress-related genes, and both perceived parental support and psychological control. Furthermore, we explored the potential mediating role of DNA methylation in stress-related genes in the associations between perceived parenting and loneliness. The sample comprised 622 early adolescents (55% girls, M_{age T1} = 10.77 years, SD_{age T1} = 0.48) who were followed from Grade 5 to 7. Parental support, psychological control, and loneliness were assessed annually by adolescent self-report questionnaires and DNA methylation was determined from saliva samples. Cross-Lagged Panel Models (CLPM) revealed that higher levels of loneliness predicted lower perceived parental support and higher perceived psychological control over time, as well as higher DNA methylation in some stress-related genes, that is, the glucocorticoid receptor gene (NR3C1) and the brain-derived neurotrophic factor (BDNF). In addition, higher NR3C1 methylation was predictive of lower perceived parental support and higher psychological control over time. No evidence was found for a mediating role of DNA methylation. Overall, our longitudinal findings challenge the current focus on DNA methylation and parenting behaviors as risk factors for adolescent loneliness. Instead, they suggest that the less considered direction of effects, which implies that loneliness predicts DNA methylation and aspects of parenting such as support and psychological control, should receive greater attention in future research.

Age differences in functional brain networks associated with loneliness and empathy

Loneliness is associated with differences in resting-state functional connectivity (RSFC) within and between large-scale networks in early- and middle-aged adult cohorts. However, age-related changes in associations between sociality and brain function into late adulthood are not well understood. Here, we examined age differences in the association between two dimensions of sociality-loneliness and empathic responding-and RSFC of the cerebral cortex. Self-report measures of loneliness and empathy were inversely related across the entire sample of younger (mean age = 22.6y, n = 128) and older (mean age = 69.0y, n = 92) adults. Using multivariate analyses of multi-echo fMRI RSFC, we identified distinct functional connectivity patterns for individual and age group differences associated with loneliness and empathic responding. Loneliness in young and empathy in both age groups was related to greater visual network integration with association networks (e.g., default, fronto-parietal control). In contrast, loneliness was positively related to within- and between-network integration of association networks for older adults. These results extend our previous findings in early- and middle-aged cohorts, demonstrating that brain systems associated with loneliness, as well as empathy, differ in older age. Further, the findings suggest that these two aspects of social experience engage different neurocognitive processes across human life-span development.

Loneliness, positive, negative and disorganised Schizotypy before and during the COVID-19 pandemic

Loneliness is common in psychosis and occurs along a continuum. Here we investigate inter-relationships between loneliness, three-dimensional schizotypy, and depressive symptoms before and during the COVID-19 pandemic.

The sample included 507 university students (48.3% participated before and 51.7% during the COVID-19 pandemic) who completed the Multidimensional Schizotypy Scale-Brief, the Counseling Center Assessment of Psychological Symptoms depression scale and the University of California, Los Angeles Loneliness Scale. Schizotypy and depression scores were regressed onto loneliness individually and in multiple regressions.

The cohorts did not differ in any of the schizotypy domains (all p > .29). Depressive symptoms (p = .05) and loneliness (p = .006) were higher during the pandemic than before. Across cohorts, loneliness was significantly associated with positive (β = 0.23, p < .001), negative (β = 0.44, p < .001), and disorganised schizotypy (β = 0.44, p < .001), and with depression (β = 0.72, p < .001). Schizotypy together explained a significant amount of variance in loneliness (R² = 0.26), with significant associations with positive (β = −0.09, p = .047), negative (β = 0.31, p < .001) and disorganised schizotypy (β = 0.34, p < .001). When depression was included (β = 0.69, p < .001), only positive (β = −0.09, p = .008) and negative schizotypy (β = 0.22, p < .001) significantly predicted loneliness.

When all schizotypy dimensions and depression were considered together, only negative schizotypy and depression significantly predicted loneliness. Loneliness and depressive symptoms were higher during the pandemic, but this did not relate to cohort differences in schizotypy.

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Loneliness is uniquely associated with negative schizotypy and depression, but not disorganised schizotypy.

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Certain aspects of positive schizotypy may protect against loneliness.

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Loneliness and depressive symptoms were higher in students during the COVID-19 pandemic than before.

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Cohorts of students assessed before and during the pandemic showed similar levels of schizotypy.

Meta-analytic evidence for the cognitive control model of loneliness in emotion processing

Loneliness is strongly related to affective dysregulation. However, the neuropsychological mechanisms underpinning the loneliness-affective processing relationships remain unclear. Here, we first utilised the coordinate-based activation likelihood estimation method to confirm functional clusters related to loneliness, including the striatum, superior and medial frontal gyrus, insula, and cuneus. Meta-analytic connectivity modelling was then performed to characterise the functional connectivity of these clusters across studies using emotion tasks. Our results revealed that these clusters co-activated with the cognitive control networks. From the literature, we understand that loneliness and its neural correlates are highly related to regulating the attention biases to social rewards and social cues. Therefore, our findings provide a proof-of-concept that loneliness up-regulates the cognitive control networks to process socio-affective information. Prolonged up-regulation thus exhausts cognitive resources and hence, affective dysregulation. This study offers insight into the intricate role of cognitive and affective regulation in loneliness and social perception and provides meta-analytic evidence of the cognitive control model of loneliness and loneliness-related affective dysregulation, bringing significant clinical implications.

Social Support and Depressive Symptoms Among Adolescents During the COVID-19 Pandemic: The Mediating Roles of Loneliness and Meaning in Life

Identifying which factors influence depressive symptom during the COVID-19 pandemic is highly significant for psychological crisis interventions among adolescents. Social support is likely to be one of the main factors. However, the underlying mechanism is still not well understood in the context of COVID-19. The current study examines whether loneliness and meaning in life mediate the association between social support and depressive symptoms in adolescents. A sample of 1,317 high school students in China were surveyed using the Perceived Social Support Scale, the Chinese Child Loneliness Scale, the Meaning in Life Questionnaire, and the Beck Depression Inventory-II. The results showed that social support predicted depressive symptoms directly and indirectly by enhancing loneliness and diminishing the sense of meaning in life. These findings help in providing new entry points in the design of effective depression prevention and intervention for adolescents during the COVID-19 pandemic.

Loneliness is not a homogeneous experience: An empirical analysis of adaptive and maladaptive forms of loneliness in the UK

Understanding loneliness is pivotal to informing relevant evidence-based preventive interventions. The present study examined the prevalence of loneliness in the UK, during the COVID-19 pandemic, and the association between loneliness, mental health outcomes, and risk and protective factors for loneliness, after controlling for the effects of social isolation. It was estimated that 18.1% of the population in our study experienced moderately high to very high loneliness. We also found that loneliness was positively associated with self-disgust and social inhibition, and negatively associated with trait optimism and hope. Cluster analysis indicated that two distinct groups emerged among those experiencing higher levels of loneliness: "adaptive" and "maladaptive" loneliness groups. The maladaptive loneliness group displayed psychological characteristics like self-disgust and social inhibition including symptoms of depression and anxiety that can potentially undermine their ability to connect with others and form meaningful social relationships. These findings suggest that not all people experience loneliness in the same way. It is possible that a one-size-fit-all approach to reducing loneliness, may be less effective because it does not take into account the differential psychological profiles and characteristics of lonely people, relevant to their capacity to connect with others.

Approach motivation and loneliness: Individual differences and parasympathetic activity

Loneliness, or perceived social isolation, is linked to a number of negative long‐term effects on both mental and physical health. However, how an individual responds to feeling lonely may influence their risk for later negative health outcomes. Here, we sought to clarify what influences variability in individuals' motivated responses to loneliness. Specifically, we assessed whether resting parasympathetic activity, a physiological marker linked to flexible adaptation, facilitates increased approach‐oriented behaviors. Seventy‐four adult participants underwent a conditioning paradigm assessing how they approach and avoid rewards and threats. Individuals with higher levels of loneliness and high resting parasympathetic activity were more likely to demonstrate approach behaviors. We discuss these findings in terms of the role resting parasympathetic activity may play in facilitating adaptive responses to feeling socially isolated.

How an individual responds to feeling lonely may influence their risk for later negative health outcomes. The current study provides new insight into what may influence variability in responses to feeling lonely. Individuals with higher resting parasympathetic activity and high levels of loneliness demonstrate increased approach‐oriented behaviors. This suggests loneliness increases approach motivations but only in the presence of other markers of adaptive responding, like high resting parasympathetic activity.

Loneliness and cardiovascular reactivity to acute stress in older adults

Loneliness has been linked to cardiovascular health outcomes in older adulthood. One proposed mechanism by which loneliness influences cardiovascular health is through atypical cardiovascular reactivity (CVR) to stress. This study is an examination of loneliness and CVR in older adults, comparing associations across two stressors and two commonly used measures of loneliness, with a particular focus on underlying hemodynamic variables including cardiac output, total peripheral resistance, and ejection time (EJT). Eighty older adults, ranging in age from 55 to 88 years (M = 68.93, SD = 8.28), completed two versions of the UCLA loneliness scale (a 20‐item and a briefer, three‐item) and took part in a laboratory stress‐testing procedure which included a mental arithmetic challenge and a public speaking task. Cardiovascular activity was monitored continuously throughout. For the 20‐item version of the UCLA loneliness scale, loneliness was not significantly related to CVR, and was only significantly associated with lower levels of overall EJT. For the three‐item version of the UCLA, no associations withstood adjustment for multiple testing. Loneliness was not reliably associated with CVR. Further, although greater loneliness was related to lower levels of overall EJT, this was only observed for the 20‐item scale. The findings do not strongly provide support for reactivity to acute stress as a pathway linking loneliness to disease outcomes, and highlight key methodological issues related to the assessment of loneliness‐reactivity associations for future.

This article provides an examination of associations between loneliness and cardiovascular reactivity (CVR) to acute stress in a sample of older adults. The findings do not provide support for a reliable association between loneliness and CVR in older adults. This article highlights methodological issues that are important to consider for future in this research area.

Choking under pressure: Does it get easier with age? How loneliness affects social monitoring across the life span

Previous experimental work showed that young adults reporting loneliness performed less well on emotion recognition tasks (Diagnostic Analysis of Nonverbal Accuracy [DANVA-2]) if they were framed as indicators of social aptitude, but not when the same tasks were framed as indexing academic aptitude. Such findings suggested that undergraduates reporting loneliness possessed the social monitoring skills necessary to read the emotions underlying others’ facial expressions, but that they choked under social pressure. It has also been found that undergraduates reporting loneliness have better recall for both positive and negative social information than their non-lonely counterparts. Whether those effects are evident across different age groups has not been examined. Using data from the British Broadcasting Corporation (BBC) Loneliness Experiment that included participants aged 16–99 years (N = 54,060), we (i) test for replication in a larger worldwide sample and (ii) extend those linear model analyses to other age groups. We found only effects for participants aged 25–34 years: In this age group, loneliness was associated with increased recall of negative individual information, and with choking under social pressure during the emotion recognition task; those effects were small. We did not find any such effects among participants in other age groups. Our findings suggest that different cognitive processes may be associated with loneliness in different age groups, highlighting the importance of life-course approaches in this area.

Affective Neuroscience of Loneliness: Potential Mechanisms underlying the Association between Perceived Social Isolation, Health, and Well-Being

Loneliness, or the subjective feeling of social isolation, is an important social determinant of health. Loneliness is associated with poor physical health, including higher rates of cardiovascular disease and dementia, faster cognitive decline, and increased risk of mortality, as well as disruptions in mental health, including higher levels of depression, anxiety, and negative affect. Theoretical accounts suggest loneliness is a complex cognitive and emotional state characterized by increased levels of inflammation and affective disruptions. This review examines affective neuroscience research on social isolation in animals and loneliness in humans to better understand the relationship between perceptions of social isolation and the brain. Loneliness associated increases in inflammation and neural changes consistent with increased sensitivity to social threat and disrupted emotion regulation suggest interventions targeting maladaptive social cognitions may be especially effective. Work in animal models suggests the neural changes associated with social isolation may be reversible. Therefore, ameliorating loneliness may be an actionable social determinant of health target. However, more research is needed to understand how loneliness impacts healthy aging, explore the role of inflammation as a potential mechanism in humans, and determine the best time to deliver interventions to improve physical health, mental health, and well-being across a diverse array of populations.

The Effect of Loneliness in Psychological and Behavioral Profile among High School Students in Spain

Loneliness is a distressing feeling that can be a barrier to a student’s development and affect their mental health. This research aimed to analyse the effects of loneliness on psychological and behavioral factors among students aged 12–19 years in Spain. Loneliness, experiential avoidance, psychological inflexibility, physical activity, mobile phone use, and smoke habits were analysed in a sample of 110 men and 122 women assigned into two groups depending on their loneliness levels: higher loneliness group (HLG) and lower loneliness group (LLG). Results showed that experimental avoidance and psychological inflexibility were related with loneliness (r = 0.471; p = 0.000). Experiential avoidance and psychological inflexibility were higher in HLG than LLG. Regarding the use of mobile phones and smoking habits, LLG presented significantly higher values than HLG. Higher age correlated with lower loneliness values (r = −0.155; p = 0.017). The present research found how students with higher loneliness presented higher experiential avoidance and psychological inflexibility and lower age, use of mobile phone, and smoking habits. These findings reveal the importance of considering multiple social behaviours when examining adolescent mental health factors.

Community identification, social support, and loneliness: The benefits of social identification for personal well-being

Levels of loneliness across the world have reached epidemic proportions, and their impact upon population health is increasingly apparent. In response, policies and initiatives have attempted to reduce loneliness by targeting social isolation among residents of local communities. Yet, little is known about the social psychological processes underpinning the relationships between community belonging, loneliness, and well-being. We report three studies which apply the Social Identity Approach to Health to examine the mechanisms underpinning the relationships between community identity, health, and loneliness. Hypotheses were tested through secondary analyses of the 2014-2015 UK Community Life Survey (N = 4,314) as well as bespoke household surveys in a more (N = 408) and less (N = 143) affluent community at high risk of loneliness. Studies 1 and 2a demonstrated that the relationship between community identification and well-being was mediated by increased social support and reduced loneliness. In Study 2b, community identification predicted well-being through reduced loneliness, but not through social support. Our results are the first to evidence these relationships and suggest that community-level interventions that enhance community identification and peer support can promote a potential Social Cure for loneliness.

Identifying Variables That Predict Depression Following the General Lockdown During the COVID-19 Pandemic

This study aimed to define the psychological markers for future development of depression symptoms following the lockdown caused by the COVID-19 outbreak. Based on previous studies, we focused on loneliness, intolerance of uncertainty and emotion estimation biases as potential predictors of elevated depression levels. During the general lockdown in April 2020, 551 participants reported their psychological health by means of various online questionnaires and an implicit task. Out of these participants, 129 took part in a second phase in June 2020. Subjective loneliness during the lockdown rather than objective isolation was the strongest predictor of symptoms of depression 5 weeks later. Younger age and health related worry also predicted higher non-clinical levels of depression and emotional distress. The results support the diathesis-stress model, which posits that a combination of preexisting vulnerabilities along with stressors such as negative life events are among the factors affecting the development of psychopathology. Moreover, our results correspond with those of previous studies conducted worldwide during the COVID-19 pandemic. Taken together, these findings call for focusing on psychological factors, especially among younger people, to identify individuals at risk for future development of depression and to promote new strategies for prevention.

Brief induction of loneliness decreases vagal regulation during social information processing

Perceived social isolation, or loneliness, has been repeatedly linked to numerous adverse health outcomes. Much effort has been directed towards elucidating the mechanisms underlying its effects on the cardiovascular system, which may explain the deleterious effects on morbidity and mortality. It has been previously suggested that perceived social isolation can impair effective parasympathetic regulation and physiological adjustment to the demands of the social environment. Thus, the present study aimed at investigating the causal impact of an induction of loneliness on vagal activity during social stimuli processing. In the study, participants (N = 119) were led to anticipate either a future filled with satisfying relationships (Future Belong) or a lonely life (Future Alone). Then, they were asked to complete an implicit emotion regulation task while their cardiovascular activity was recorded. In the Future Belong group, a pattern of vagal suppression was observed between the resting period and task completion, which was followed by vagal recovery during the post-task resting period. However, in the Future Alone group, a change from the baseline HRV was observed only at the beginning of the task, but not during its consecutive stages. Moreover, in participants who believed in the given FA feedback, the initial vagal suppression was absent. These findings provide evidence that even a brief induction of loneliness can result in a blunted vagal suppression during social information processing. It can be hypothesized that the lack of the ability to regulate vagal activity while processing social cues may potentially underlie problems with social engagement and self-control.

Peer network Status and Depressive Symptoms Among Early Adolescents: Testing the Mediating Effects of Metaperception and Loneliness

Previous research shows that deficits in social relationships increase the risk of depression. This study tests the hypothesis that among early adolescents, their status in their peer network (likeability/dislikeability) will be associated with depressive symptoms but only indirectly, through the subjective perception of this status (positive/negative metaperception) and loneliness (feeling of social isolation). Data were collected using sociometric methods and self-report scales from 388 students aged 12–13. Path analysis was applied to verify the hypothesized relationships between the study variables. The findings indicate that: (1) status in the peer network and its perception affect depressive symptoms only indirectly, through loneliness; (2) depressive symptoms depend directly on loneliness alone; (3) status in the peer network does not directly translate into loneliness—its effect is mediated by metaperception; (4) the negative dimension of the peer network status indirectly affects both loneliness and depressive symptoms more strongly than the positive one. The main limitation of the research is its cross-sectional design, which precludes definite conclusions about the direction of the relationships observed. The results obtained help to clarify the complex mechanisms through which objective status in the peer network, its subjective perception and feelings of loneliness contribute to the severity of depressive symptoms among early adolescents. On the practical side, the findings highlight the importance of developing and implementing interventions targeting both the objective and subjective aspects of social relations for the prevention of depression in this age group.

Loneliness, Social Isolation and Their Difference: A Cross-Diagnostic Study in Persistent Depressive Disorder and Borderline Personality Disorder

Background: Interpersonal difficulties are a key feature of persistent depressive disorder (PDD) and borderline personality disorder (BPD). Caught in a vicious circle of dysfunctional interpersonal transaction, PDD and BPD patients are at great risk of experiencing prolonged loneliness. Loneliness, in turn, has been associated with the development of mental disorders and chronic illness trajectories. Besides, several factors may contribute to the experience of loneliness across the lifespan, such as social network characteristics, a history of childhood maltreatment (CM), and cognitive-affective biases such as rejection sensitivity (RS). This cross-diagnostic study approached the topic of perceived loneliness by comparing PDD and BPD patients with healthy controls (HC) in its interplay with symptom burden, social network characteristics, RS as well as CM. Method: Thirty-four PDD patients (DSM-5; 15 female, Mage = 38.2, SD = 12.3), 36 BPD patients (DSM-5; 19 female, Mage = 28.8, SD = 9.2), and 70 age- and gender-matched HC were assessed cross-sectionally using the following self-report measures: UCLA Loneliness Scale, Social Network Index (SNI; size, diversity, and embeddedness), Beck Depression Inventory (BDI-II), Borderline Symptom List (BSL-23), Childhood Trauma Questionnaire (CTQ), and Rejection Sensitivity Questionnaire (RSQ). Results: Both patient groups reported significantly higher levels of perceived loneliness, symptom severity, and smaller social network characteristics compared to HC. Loneliness was significantly correlated with severity of self-reported clinical symptoms in PDD and at trend level in BPD. Besides, loneliness tended to be related to social network characteristics for all groups except PDD patients. Both PDD and BPD patients showed higher RS as well as CTQ scores than HC. A history of emotional abuse and emotional neglect was associated with loneliness, and this association was mediated by RS as demonstrated by an exploratory mediation analysis. Discussion: Loneliness is highly prevalent in PDD and BPD patients and contributes to the overall symptom burden. Interestingly, loneliness showed an association with prior experiences of CM as well as current RS. We therefore propose a comprehensive model on how intra- und interpersonal aspects may interplay in the dynamics of loneliness in light of CM. Finally, this model may have further implications for psychotherapeutic interventions.

A Machine Learning Approach for the Automatic Estimation of Fixation-Time Data Signals' Quality

Fixation time measures have been widely adopted in studies with infants and young children because they can successfully tap on their meaningful nonverbal behaviors. While recording preverbal children's behavior is relatively simple, analysis of collected signals requires extensive manual preprocessing. In this paper, we investigate the possibility of using different Machine Learning (ML)-a Linear SVC, a Non-Linear SVC, and K-Neighbors-classifiers to automatically discriminate between Usable and Unusable eye fixation recordings. Results of our models show an accuracy of up to the 80%, suggesting that ML tools can help human researchers during the preprocessing and labelling phase of collected data.

The Neurobiology of Social Distance

Never before have we experienced social isolation on such a massive scale as we have in response to coronavirus disease 2019 (COVID-19). However, we know that the social environment has a dramatic impact on our sense of life satisfaction and well-being. In times of distress, crisis, or disaster, human resilience depends on the richness and strength of social connections, as well as on active engagement in groups and communities. Over recent years, evidence emerging from various disciplines has made it abundantly clear: perceived social isolation (i.e., loneliness) may be the most potent threat to survival and longevity. We highlight the benefits of social bonds, the choreographies of bond creation and maintenance, as well as the neurocognitive basis of social isolation and its deep consequences for mental and physical health.

2019 Novel Coronavirus Disease, Crisis, and Isolation

The highly contagious 2019 novel coronavirus disease (COVID-19) outbreak has not only impacted health systems, economies, and governments, it has also rapidly grown into a global health crisis, which is now threatening the lives of millions of people globally. While, on one hand, medical institutions are critically attempting to find a cure, on the other hand, governments have introduced striking measures and policies to curtail the rapid spread of the disease. Although COVID-19 has achieved pandemic status and is predominantly viewed as a biomedical issue, it is argued that it should also be treated as a psychological crisis. This paper also reviews the literature to examine and comment on the detrimental effects of isolation, which has been enforced as one of the primary preventative measures to manage the spread of COVID-19. This paper further outlines key recommendations that should be addressed across different levels to buffer against the known adverse effects of isolation, which is especially relevant for the current COVID-19 situation, where a large proportion of the global population is isolated, confined, and/or quarantined.

Absence and Presence of Human Interaction: The Relationship Between Loneliness and Empathy

Loneliness is the negative experience of a discrepancy between the desired and actual personal network of relationships. Whereas past work have focused on the effect of loneliness on prosocial behaviors, the present research addressed the gap by exploring the effect of loneliness on empathy. Empathy is the emotional reaction of sharing in others' internal experiences. We adopted a new paradigm-empathy selection task, which uses free choices to assess the desire to empathize. Participants made a series of binary choices, selecting situations that instructed them to empathize or objectively describe. Results from two studies showed that, compared to non-lonely people, lonely people were more likely to choose positive empathy but to avoid negative empathy. The pattern occurs because lonely people perceived higher (vs. lower) social support in the positive (vs. negative) empathy tasks. Moreover, empathy served to be an adaptive emotion regulation strategy developed by lonely people to reduce their loneliness effectively. This research has resulted in both theoretical contributions to prosocial behavior literature and the further discovery of practical implications for loneliness intervention.

Future Directions in Peer Relations Research

Peer relationships among youth have been examined as predictors of mental health outcomes for at least fifty years, revealing dozens of discrete peer constructs that each are associated with adjustment in childhood, adolescence, and later in adulthood. Future research may benefit by examining a range of new outcomes and psychological processes that have been discussed recently in related literatures. This paper reviews recent research on interpersonal determinants of physical health outcomes, and opportunities for greater examination of 1) peer influence processes toward health risk behaviors; 2) neural correlates of peer adversity; 3) adverse peer experiences that may affect physiological markers of stress response; and 4) immune system markers of peer adversity. Additional future directions include the study of differences in the forms and functions of peer interactions within the digital age.

Loneliness in the lives of Danish adolescents: Associations with health and sleep

Aims: We examined the relationship between loneliness and health among young adolescents. We also investigated the validity of a single-item measure of loneliness by comparing this to a composite score. Methods: The current data come from a nationally representative sample of 11- to 15-year-old adolescents (N=3305; F=52%) from Denmark collected in 2014 as part of the Health Behaviour in School-aged Children (HBSC) collaborative cross-national survey. Results: A series of binary logistic regressions showed that higher loneliness among adolescents, whether measured using the single- or multi-item measurement, was associated with poorer self-rated health, higher frequency of headache, stomach ache, backache, difficulties sleeping, greater sleep disturbance and more instances of feeling tired in the morning. Those associations were relatively consistent across sex and age groups. Conclusions:Loneliness is associated with poorer self-reported health and sleep problems among young adolescents. Those findings are similar across two measures of loneliness, suggesting robust findings. The development of interventions and health-education efforts to fight loneliness in adolescence is important.

Loneliness and meaning in life are reflected in the intrinsic network architecture of the brain

Social relationships imbue life with meaning, whereas loneliness diminishes one's sense of meaning in life. Yet the extent of interdependence between these psychological constructs remains poorly understood. We took a multivariate network approach to examine resting-state fMRI functional connectivity’s association with loneliness and meaning in a large cohort of adults (N = 942). Loneliness and meaning in life were negatively correlated with one another. In their relationship with individually parcelled whole-brain measures of functional connectivity, a significant and reliable pattern was observed. Greater loneliness was associated with dense, and less modular, connections between default, frontoparietal, attention and perceptual networks. A greater sense of life meaning was associated with increased, and more modular, connectivity between default and limbic networks. Low loneliness was associated with more modular brain connectivity, and lower life meaning was associated with higher between-network connectivity. These findings advance our understanding of loneliness and life meaning as distinct, yet interdependent, features of sociality. The results highlight a potential role of the default network as a central hub, providing a putative neural mechanism for shifting between feelings of isolation and purpose.

Connectome-based individualized prediction of loneliness

Loneliness is an increasingly prevalent condition linking with enhanced morbidity and premature mortality. Despite recent proposal on medicalization of loneliness, so far no effort has been made to establish a model capable of predicting loneliness at the individual level. Here, we applied a machine-learning approach to decode loneliness from whole-brain resting-state functional connectivity (RSFC). The relationship between whole-brain RSFC and loneliness was examined in a linear predictive model. The results revealed that individual loneliness could be predicted by within- and between-network connectivity of prefrontal, limbic and temporal systems, which are involved in cognitive control, emotional processing and social perceptions and communications, respectively. Key nodes that contributed to the prediction model comprised regions previously implicated in loneliness, including the dorsolateral prefrontal cortex, lateral orbital frontal cortex, ventromedial prefrontal cortex, caudate, amygdala and temporal regions. Our findings also demonstrated that both loneliness and associated neural substrates are modulated by levels of neuroticism and extraversion. The current data-driven approach provides the first evidence on the predictive brain features of loneliness based on organizations of intrinsic brain networks. Our work represents initial efforts in the direction of making individualized prediction of loneliness that could be useful for diagnosis, prognosis and treatment.

When friends behave badly: Loneliness and children's expectations of friends and responses to transgressions

Previous research has shown that friendships buffer against loneliness, but some children remain lonely despite having best friends. The current study examines relationships between loneliness and Friendship Functions, expectations, and responses to friendship transgressions in children with best friends (8-11 years; N = 177). Children completed questionnaires that measured loneliness, fulfilment of Friendship Functions, Friendship Expectations, and the Transgressions of Friendship Expectations Questionnaire (MacEvoy & Asher, Child Development, 83, 2012, 104). Findings in the current study showed that loneliness was associated with lower Friendship Expectations and higher reliable alliance in existing best friendships. Loneliness was also associated with lower sadness and lower perceptions of feeling controlled and devalued by their friend when they transgress. Thus, children with best friends experiencing high loneliness may be more permissiveness of friendship transgressions and may need support to ensure that they do not allow their friends to be unfair to them. Statement of contribution What is already known on the subject? Friendships buffer children from loneliness, but some remain lonely despite having friends. Loneliness has been associated with poor-quality friendships. But there is no examination of why children remain lonely when they have friends. What the present study adds? Lonely children overemphasize friendship qualities that help to maintain the relationship. Loneliness was linked to expectations of being friends with less popular and well-liked peers. Lonely children placed less blame on their friends when they violated Friendship Expectations.

The Role of Emotional Intelligence in the Maintenance of Depression Symptoms and Loneliness Among Children

Identifying factors that predict the maintenance of depression and loneliness in children is important for intervention design. Whilst emotional intelligence (EI) has been identified as a predictor of mental health, research examining how both trait and ability EI contribute to long-term patterns of symptomatology in children is markedly absent. We examined the impact of both TEI and AEI on the maintenance of loneliness and depressive symptoms over 1 year in children aged 9-11 years. Two hundred and thirteen children (54% male) completed the TEIQue-CF and the MSCEIT-YV at the first time point of the study, and the Child Depression Inventory and the Loneliness and Aloneness Scale for Children and Adolescents at Time 1 and, again, 1 year later. Findings indicate that emotional skills (AEI) are important for predicting the maintenance of depressive symptoms and loneliness in children over 1 year; emotional self-competency (TEI) is less influential, only contributing to long-term loneliness in girls. Moreover, whilst deficiencies in the ability to perceive and understand emotions were predictive of prolonged symptomatology, so, too, were proficiencies in using emotion to facilitate thinking and emotion management. Those findings carry important implications for EI theory and future research. They also indicate that EI interventions tailored to groups of "at risk" school children may be useful for reducing specific profiles of internalizing symptoms. Programs targeting AEI skills may be universally helpful for reducing the likelihood that depressive symptoms and loneliness will be maintained over time in middle childhood; girls at risk for prolonged loneliness would additionally benefit from opportunities to bolster TEI.

Loneliness and Neighborhood Characteristics: A Multi-Informant, Nationally Representative Study of Young Adults

In this study, we investigated associations between the characteristics of the neighborhoods in which young adults live and their feelings of loneliness, using data from different sources. Participants were drawn from the Environmental Risk Longitudinal Twin Study. Loneliness was measured via self-reports at ages 12 and 18 years and also by interviewer ratings at age 18. Neighborhood characteristics were assessed between the ages of 12 and 18 via government data, systematic social observations, a resident survey, and participants' self-reports. Greater loneliness was associated with perceptions of lower collective efficacy and greater neighborhood disorder but not with more objective measures of neighborhood characteristics. Lonelier individuals perceived the collective efficacy of their neighborhoods to be lower than did their less lonely siblings who lived at the same address. These findings suggest that feelings of loneliness are associated with negatively biased perceptions of neighborhood characteristics, which may have implications for lonely individuals' likelihood of escaping loneliness.

Loneliness predicts a preference for larger interpersonal distance within intimate space

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.

Thwarted Belongingness in Relation to Face-to-Face and Online Interactions

Suicide is ranked as the tenth leading cause of death for all ages in the United States (Centers for Disease Control and Prevention, 2012). Joiner's (2005) interpersonal theory of suicide stated thwarted belongingness-the feeling of being alienated from others-and perceived burdensomeness-the feeling of being a liability to others-are the primary proximal factors leading to suicidal desire. The current study focused on thwarted belongingness and examined its relationship to face-to-face interactions and online interactions in both an undergraduate and community sample. We hypothesized that negative face-to-face and online interactions would be independently associated with higher levels of thwarted belongingness. Furthermore, we hypothesized that face-to-face interactions would moderate the relationship between online interactions and thwarted belongingness and that online interactions would moderate the relationship between face-to-face interactions and thwarted belongingness. Three hundred eighty-seven participants (79.6% female) at a southern university and 209 (62.7% male) participants recruited from Amazon's Mechanical Turk website completed an online survey. Results only partially supported hypotheses, with only face-to-face interactions shown to be independently related to higher levels of thwarted belongingness. These findings indicated that negative face-to-face interactions may contribute to higher levels of risk factors for suicide ideation and highlighted the importance of assessing for negative interactions across all contexts.

Loneliness, HPA stress reactivity and social threat sensitivity: Analyzing naturalistic social challenges

Loneliness has been linked to poor health through an increased activation of threat surveillance mechanisms, such as the hypothalamic-pituitary-adrenal axis (HPA). The socio-cognitive model (Cacioppo & Hawley) proposes that lonely people have an increased social threat sensitivity which activates the HPA axis. The current study examined the impact of loneliness on HPA stress reactivity and social threat sensitivity in response to naturally occurring social challenges. Participants (N = 45) were prospective undergraduates attending a 3-day university preparation programme over the summer, prior to commencing their university studies. Cortisol levels and perceived stress were measured before and after an ice breaker session on Day 1 and a lecture session on Day 3. Social threat sensitivity was also measured on the first and third day. When meeting unfamiliar peers in the ice breaker session, HPA stress reactivity was evident, but it was not markedly different in those who reported high levels of loneliness than those with low levels. The high loneliness group had higher levels of perceived stress and increased social threat sensitivity than the low loneliness group on both testing days. The findings show partial support for the socio-cognitive model of loneliness because increased threat sensitivity was demonstrated in the high loneliness group. The findings indicate that lonely people do not respond in a physiologically different way to specific social challenges, but they typically report higher social threat sensitivity and higher perceived stress than their non-lonely peers.

Attention bias for social threat in youth with tic disorders: Links with tic severity and social anxiety

Many individuals with Tourette syndrome and chronic tic disorders (TS/CTDs) report poor social functioning and comorbid social anxiety. Yet limited research has investigated the role of cognitive factors that highlight social threats in youth with TS/CTD, and whether these biases underlie tic severity and co-occurring social anxiety. This study examined whether selective attention to social threat is enhanced young people with TS/CTDs compared to healthy controls, and whether attention biases are associated with tic severity and social anxiety. Twenty seven young people with TS/CTDs and 25 matched control participants completed an experimental measure of attention bias toward/away from threat stimuli. A clinician-rated interview measuring tic severity/impairment (YGTSS Total Score) and questionnaire measures of social anxiety were completed by participants and their parents. Young people with TS/CTD showed an attention bias to social threat words (relative to benign words) compared to controls but no such bias for social threat faces. Attention bias for social threat words was associated with increasing YGTSS Total Score and parent-reported social anxiety in the TS/CTDs group. Mediation analysis revealed a significant indirect path between YGTSS Total Score and social anxiety, via attention to social threat. Tentatively, these associations appeared to be driven by impairment rather than tic severity scores. Preliminary data suggests that youth with TS/CTD have enhanced attention to threat, compared to controls, and this is associated with impairment and social anxiety. Attention to threat could offer a cognitive mechanism connecting impairment and social anxiety, and so be a valuable trans-diagnostic treatment target.