Sleep quality impacts the link between reactivity to uncertain threat and anxiety and alcohol use in youth.

Individual differences in reactivity to unpredictable threat (U-threat) have repeatedly been linked to symptoms of anxiety and drinking behavior. An emerging theory is that individuals who are hyper-reactive to U-threat experience chronic anticipatory anxiety, hyperarousal, and are vulnerable to excessive alcohol use via negative reinforcement processes. Notably, anxiety and alcohol use commonly relate to disruptions in sleep behavior and recent findings suggest that sleep quality may impact the link between reactivity to U-threat and psychiatric symptoms and behaviors. The aim of the current study was to examine the unique and interactive effects of reactivity to U-threat and sleep quality on anxiety symptoms and drinking behavior in a cohort of youth, ages 16-19 years. Participants (N = 112) completed a well-validated threat-of-shock task designed to probe individual differences in reactivity to U-threat and predictable threat (P-threat). Startle eyeblink potentiation was recorded during the task as an index of aversive reactivity. Participants also completed well-validated self-report measures of anxiety and depression symptoms, lifetime alcohol use, and current sleep quality. Results revealed significant startle reactivity to U-threat by sleep quality interactions on anxiety symptoms and lifetime drinking behavior. At high levels of sleep disturbance (only), greater reactivity to U-threat was associated with greater anxiety symptoms and total number of lifetime alcoholic beverages. These results suggest that sensitivity to uncertainty and chronic hyperarousal increases anxiety symptoms and alcohol use behavior, particularly in the context of poor sleep quality.

Correction: Social Media Use and Its Concurrent and Subsequent Relation to a Biological Marker of Inflammation: Short-Term Longitudinal Study.

[This corrects the article DOI: 10.2196/46309.].

Everyday co-presence with a romantic partner is associated with lower C-reactive protein.

Social relationships are an important driver of health, and inflammation has been proposed as a key neurobiological mechanism to explain this effect. Behavioral researchers have focused on social relationship quality to further explain the association, yet recent research indicates that relationship quality may not be as robust a predictor as previously thought. Here, building on animal models of social bonds and recent theory on close relationships, we instead investigated merely being in the physical presence of one's romantic partner. Specifically, we tested the hypothesis that spending more time co-present with a loved partner in everyday life would be associated with lower C-reactive protein (CRP). Three times over the course of one month, 100 people in romantic relationships reported how much time they spent in the same physical space as their partner in the prior 24 h, in minutes, and provided a sample of blood for CRP assay (n observations = 296). Results from multi-level models showed that when one reported spending more time in the physical presence of their partner they had lower CRP - an effect that was independent from social relationship quality explanations from the prior literature, including romantic relationship quality, hostility, and loneliness. These findings move past global assessments of social isolation to consider a novel everyday behavior that is of great interest in the non-human animal literature - spending time together -- as a potential mechanism linking high-quality relationships and physical health in adult humans. The findings also point to future research on additional behavioral mechanisms that are not dependent on stress pathways: people in high-quality relationships tend to spend enjoyable and affectionate time with one another, which may impact inflammation.

Can inflammation predict social media use? Linking a biological marker of systemic inflammation with social media use among college students and middle-aged adults.

Drawing on recent evidence that inflammation may promote social affiliative motivation, the present research proposes a novel perspective that inflammation may be associated with more social media use. In a cross-sectional analysis of a nationally representative sample, Study 1 (N = 863) found a positive association between C-reactive protein (CRP), a biomarker of systemic inflammation, and the amount of social media use by middle-aged adults. Study 2 (N = 228) showed that among college students CRP was prospectively associated with more social media use 6 weeks later. Providing stronger evidence of the directionality of this effect, Study 3 (N = 171) showed that in college students CRP predicted increased social media use in the subsequent week even after controlling for current week's use. Additionally, in exploratory analyses of CRP and different types of social media use in the same week, CRP was only associated with using social media for social interaction and not for other purposes (e.g., entertainment). The present research sheds light on the social effects of inflammation and highlights potential benefits of using social media as a context for studying the impact of inflammation on social motivation and behavior.

Typhoid vaccine does not impact feelings of social connection or social behavior in a randomized crossover trial among middle-aged female breast cancer survivors.

BACKGROUND: Inflammation can have social consequences, which may be relevant to inflammation's link with depression. The current study tests whether a typhoid vaccine increases feelings of social disconnection and avoidance behavior. METHOD: In two full-day visits at least three weeks apart, 172 postmenopausal breast cancer survivors (Stage I-IIIA) each received a typhoid capsular polysaccharide vaccination and a saline placebo injection in a random sequence. Blood was drawn prior to the injection, as well as every 90 min thereafter for 8 h to assess the inflammatory response (interleukin-6, IL-6; interleukin-1 receptor antagonist, IL-1Ra). At both visits, women completed the Social Connection Scale at 0 and 8.5 h post-vaccination as well as implicit and explicit social avoidance tasks at 7 h post-vaccination. RESULTS: The typhoid vaccine triggered rises in both inflammatory markers (ps < 0.01), but it did not impact feelings of social connection (p = .32), or performance on the implicit (p = .34) or explicit tasks (p = .37). Inflammatory rises did not predict feelings of social connection (ps > 0.64) or performance on explicit (ps > 0.73) or implicit (ps > 0.88) social avoidance tasks. CONCLUSION: Milder inflammatory stimuli may not affect social processes. Higher levels of inflammation or, relatedly, more sickness symptoms may be necessary to recapitulate prior findings of social avoidance.

Social Media Use and Its Concurrent and Subsequent Relation to a Biological Marker of Inflammation: Short-Term Longitudinal Study.

BACKGROUND: Although many studies have examined the impact of social media use (SMU) on mental health, very few studies have examined the association of SMU with health-relevant biomarkers. OBJECTIVE: Addressing this gap, we conducted a short-term longitudinal study examining the link between SMU and C-reactive protein (CRP), a biological marker of systemic inflammation predictive of major depression, chronic diseases, and mortality. METHODS: We measured college students' weekly amount of SMU for 5 consecutive weeks objectively via the Screen Time app and collected blood samples at baseline and 5 weeks later. RESULTS: In separate cross-sectional analyses conducted at phase 1 (baseline) and at phase 2 (5 weeks after baseline), objective SMU had a positive, concurrent association with CRP at both time points. Critically, in a longitudinal analysis, more SMU between phase 1 and phase 2 predicted increased CRP between these time points, suggesting that increased SMU led to heightened inflammation during that period. CONCLUSIONS: Although more research is needed to understand why SMU led to higher inflammation, the association between objective SMU and a marker of a biological process critical to physical health presents an intriguing opportunity for future research on social media effects.

Perceived social support-giving moderates the association between social relationships and interleukin-6 levels in blood.

Although positive social relationships are assumed to relate to lower levels of chronic systemic inflammation, the empirical evidence on this association is mixed. This study examines whether perceived social support-giving (i.e., the belief that one can be available to give social support to others, henceforward referred to as perceived support-giving) moderates associations between social relationships and inflammation using data from the longitudinal follow-up of the National Survey of Midlife Development in the U.S. (MIDUS II). Middle-aged adults (N = 1054) completed self-report questionnaires on social integration, perceived support-availability from others, positive relations with others, perceived support-giving, socio-demographic information, and health-related information and provided blood samples for measurement of interleukin-6 (IL-6) as a marker of systemic inflammation. The results showed that perceived support-giving moderated the associations between IL-6 and indicators of positive social relationships, including social integration, perceived support-availability, and positive relations with others. Indicators of positive social relationships were associated with lower IL-6 among individuals higher, but not lower, in perceived support-giving. The moderating effects of perceived support-giving held after adjusting for socio-demographic and health-related covariates. Therefore, positive social relationships are associated with lower IL-6 only for individuals who believe they can give more support in those relationships. In addition, preliminary evidence indicated that the moderating effects of perceived support-giving might be further qualified by gender, being significant only in women.

Racial and Economic Adversity Differences in Stress Markers and Immune Function Among Urban Adolescents.

BACKGROUND: Exposure to racism and associated adversities, such as poverty, is hypothesized to contribute to racial inequities in health via stress and immune pathways. Furthermore, the effects of adversity may be more salient during sensitive developmental periods. Our study examined racial differences in stress and immune biomarkers during adolescence and the effects of exposure to economic adversity at distinct developmental time periods and cumulatively in accounting for potential racial differences. METHODS: Secondary analysis of the Adolescent Health and Development in Context study was conducted. Data were derived from self-administered surveys; interviews; smartphone-based, geographic-explicit ecological momentary assessment; stress biomarkers (evening salivary cortisol over six nights and hair cortisol); and immune biomarkers (salivary shedding of Epstein-Barr virus [EBV] DNA among EBV-positive adolescents). Current socioeconomic status measures included annual household income and caregiver education. Caregivers also reported experiences of bankruptcy, difficulty paying bills, receipt of food stamps/Supplemental Nutrition Assistance Program/electronic benefit transfer, and job loss when the child was of ages birth-5 years, 6-10 years, and 11 years or older. An affirmative response to any item was defined as exposure to economic adversity for that developmental time period (yes/no). A cumulative economic adversity measure was calculated as the sum of exposures across developmental periods (0 = never exposed to 3 = exposed across all time periods). Descriptive and multivariable regression analyses were conducted, accounting for covariates. RESULTS: Black/African American adolescents had higher salivary cortisol concentration, higher hair cortisol concentration, and an increased odd of salivary shedding of EBV DNA compared to White adolescents. Racial differences were not attenuated by the current socioeconomic status or economic adversity (developmental period or cumulatively). DISCUSSION: Our study provides evidence that stress and immune biomarkers differ by race as early as adolescence and may be one pathway through which racism and associated adversities contribute to racial health inequities. Further research on the contribution of multiple adversities beyond poverty to racial inequities in physiological stress and health is critical for informing effective prevention and intervention efforts.

Stereotype threat, trait perseveration, and vagal activity: evidence for mechanisms underpinning health disparities in Black Americans.

Objective: Black Americans (BAs) are at an elevated risk for morbidity and mortality in comparison to White Americans (WAs). Racial stressors are a common occurrence in American culture and is theorized to contribute to these disparities. When race-focused, stereotype threat (ST) is considered to be a factor that is detrimental to health in BAs; however few studies have directly investigated the impact of a ST manipulation on physiological function. Furthermore, it is proposed that racial stressors such as ST may have prolonged effects when more likely to perseverate (e.g. rumination) over the stressor and thus, those with greater trait perseveration may be more affected by ST. We sought to explore the impact of ST and trait perseveration on changes in vagus nerve activity - an indication of adaptive psychological and physiological well-being - as indexed by vagally mediated heart rate variability (vmHRV). Design: Forty-three (24 females, mean age of 20, standard deviation of 3 years) apparently healthy BA individuals were randomly assigned to one of three experimental conditions in which they received either implicit (subtle), explicit (blatant), or no ST priming (control condition), prior to completing a cognitive task. Resting vmHRV was assessed both at baseline (pre-task) and recovery (post-task). Results: BAs in the explicit ST condition exhibited the greatest decrease in vmHRV in comparison to the control group from pre- to post-task. BAs with moderate to high levels of trait perseveration showed the greatest decrease in vmHRV from pre- to post-task in comparison to those with lower levels of trait perseveration and BAs in the control group. Conclusion: These data suggest that racial ST, especially when explicit and coupled with trait perseveration, can decrease vagal activity, as indexed by decreased vmHRV, which when experienced frequently can have significant consequences for health and longevity in BAs.

Over-the-Counter Relief From Pains and Pleasures Alike: Acetaminophen Blunts Evaluation Sensitivity to Both Negative and Positive Stimuli.

Acetaminophen, an effective and popular over-the-counter pain reliever (e.g., the active ingredient in Tylenol), has recently been shown to blunt individuals' reactivity to a range of negative stimuli in addition to physical pain. Because accumulating research has shown that individuals' reactivity to both negative and positive stimuli can be influenced by a single factor (an idea known as differential susceptibility), we conducted two experiments testing whether acetaminophen blunted individuals' evaluations of and emotional reactions to both negative and positive images from the International Affective Picture System. Participants who took acetaminophen evaluated unpleasant stimuli less negatively and pleasant stimuli less positively, compared with participants who took a placebo. Participants in the acetaminophen condition also rated both negative and positive stimuli as less emotionally arousing than did participants in the placebo condition (Studies 1 and 2), whereas nonevaluative ratings (extent of color saturation in each image; Study 2) were not affected by drug condition. These findings suggest that acetaminophen has a general blunting effect on individuals' evaluative and emotional processing, irrespective of negative or positive valence.

Oxytocin receptor gene (OXTR) is related to psychological resources.

Psychological resources--optimism, mastery, and self-esteem--buffer the deleterious effects of stress and are predictors of neurophysiological and psychological health-related outcomes. These resources have been shown to be highly heritable, yet the genetic basis for this heritability remains unknown. Here, we report a link between the oxytocin receptor (OXTR) SNP rs53576 and psychological resources, such that carriers of the "A" allele have lower levels of optimism, mastery, and self-esteem, relative to G/G homozygotes. OXTR was also associated with depressive symptomatology. Mediation analysis indicates that the effects of OXTR on depressive symptoms may be largely mediated by the influence of OXTR on psychological resources.

Neural sensitivity to social rejection is associated with inflammatory responses to social stress.

Although stress-induced increases in inflammation have been implicated in several major disorders, including cardiovascular disease and depression, the neurocognitive pathways that underlie inflammatory responses to stress remain largely unknown. To examine these processes, we recruited 124 healthy young adult participants to complete a laboratory-based social stressor while markers of inflammatory activity were obtained from oral fluids. A subset of participants (n = 31) later completed an fMRI session in which their neural responses to social rejection were assessed. As predicted, exposure to the laboratory-based social stressor was associated with significant increases in two markers of inflammatory activity, namely a soluble receptor for tumor necrosis factor-alpha (sTNFalphaRII) and interleukin-6 (IL-6). In the neuroimaging subsample, greater increases in sTNFalphaRII (but not IL-6) were associated with greater activity in the dorsal anterior cingulate cortex and anterior insula, brain regions that have previously been associated with processing rejection-related distress and negative affect. These data thus elucidate a neurocognitive pathway that may be involved in potentiated inflammatory responses to acute social stress. As such, they have implications for understanding how social stressors may promote susceptibility to diseases with an inflammatory component.

Everyday perceptions of safety and racial disparities in hair cortisol concentration.

OBJECTIVE: Black-White disparities in physiological stress during adolescence are increasingly evident but remain incompletely understood. We examine the role of real-time perceptions of safety in the context of everyday routines to gain insight into the sources of observed adolescent racial differences in chronic stress as measured by hair cortisol concentration (HCC). METHOD: We combined social survey, ecological momentary assessment (EMA), and hair cortisol data on 690 Black and White youth ages 11-17 from wave 1 of the Adolescent Health and Development in Context (AHDC) study to investigate racial differences in physiological stress. Individual-level, reliability-adjusted measures of perceived unsafety outside the home were drawn from a week-long smartphone-based EMA and tested for association with hair cortisol concentration. RESULTS: We observed a statistically significant interaction (p < .05) between race and perceptions of unsafety. For Black youth, perceived unsafety was associated with higher HCC (p < .05). We observed no evidence of an association between perceptions of safety and expected HCC for White youth. For youth who perceive their out-of-home activity locations to be consistently safe, the racial difference in expected HCC was not statistically significant. At the high end of perceived unsafety, however, Black-White differences in HCC were pronounced (0.75 standard deviations at the 95th percentile on perceived unsafety; p < .001). DISCUSSION: These findings call attention to the role of everyday perceptions of safety across non-home routine activity contexts in explaining race differences in chronic stress as assessed by hair cortisol concentrations. Future research may benefit from data on in situ experiences to capture disparities in psychological and physiological stress.

Social status modulates neural activity in the mentalizing network.

The current research explored the neural mechanisms linking social status to perceptions of the social world. Two fMRI studies provide converging evidence that individuals lower in social status are more likely to engage neural circuitry often involved in 'mentalizing' or thinking about others' thoughts and feelings. Study 1 found that college students' perception of their social status in the university community was related to neural activity in the mentalizing network (e.g., DMPFC, MPFC, precuneus/PCC) while encoding social information, with lower social status predicting greater neural activity in this network. Study 2 demonstrated that socioeconomic status, an objective indicator of global standing, predicted adolescents' neural activity during the processing of threatening faces, with individuals lower in social status displaying greater activity in the DMPFC, previously associated with mentalizing, and the amygdala, previously associated with emotion/salience processing. These studies demonstrate that social status is fundamentally and neurocognitively linked to how people process and navigate their social worlds.

Maternal and offspring dopamine D4 receptor genotypes interact to influence juvenile impulsivity in vervet monkeys.

The merging of psychological and genetic methodologies has led to an increasing appreciation of environmental moderators of the relationships between genotype and phenotype. Here we used a nonhuman-primate model to study the moderating effect of the mother's genotype on the association of a dopamine D4 receptor (DRD4) gene polymorphism with juvenile impulsivity, assessed in a standardized social-challenge test. The results showed that juvenile carriers of the rare 5-repeat variant of the exon III 48-base-pair repeat polymorphism scored significantly higher in social impulsivity than juveniles homozygous for the common 6-repeat allele. In addition, juvenile genotype interacted with maternal genotype to influence impulsivity, with the highest rates of impulsivity found in variant offspring with variant mothers. These results highlight the importance of considering the genotype of the parents in studies of early experience and vulnerability genes for impulsivity-related traits.

Variation in the mu-opioid receptor gene (OPRM1) is associated with dispositional and neural sensitivity to social rejection.

Scientific understanding of social pain--the hurt feelings resulting from social rejection, separation, or loss--has been facilitated by the hypothesis that such feelings arise, in part, from some of the same neural and neurochemical systems that generate the unpleasant feelings resulting from physical pain. Accordingly, in animals, the painkiller morphine not only alleviates the distress of physical pain, but also the distress of social separation. Because morphine acts on the mu-opioid receptor, we examined whether variation in the mu-opioid receptor gene (OPRM1), as measured by the functional A118G polymorphism, was associated with individual differences in rejection sensitivity. Participants (n = 122) completed a self-report inventory of dispositional sensitivity to social rejection and a subsample (n = 31) completed a functional MRI session in which they were rejected from an online ball-tossing game played with two supposed others. The A118G polymorphism was associated with dispositional sensitivity to rejection in the entire sample and in the fMRI subsample. Consistent with these results, G allele carriers showed greater reactivity to social rejection in neural regions previously shown to be involved in processing social pain as well as the unpleasantness of physical pain, particularly the dorsal anterior cingulate cortex (dACC) and anterior insula. Furthermore, dACC activity mediated the relationship between the A118G polymorphism and dispositional sensitivity to rejection, suggesting that this is a critical site for mu-opioid-related influence on social pain. Taken together, these data suggest that the A118G polymorphism specifically, and the mu-opioid receptor more generally, are involved in social pain in addition to physical pain.

Social Media Use and Its Link to Physical Health Indicators.

Social media use has become an integral part of many young adults' daily lives. Although much research has examined how social media use relates to psychological well-being, little is known about how it relates to physical health. To address this knowledge gap, the present research investigated how the amount of social media people use relates to various indices of physical health. Young adults provided a blood sample that was analyzed for C-reactive protein (CRP), a marker of chronic inflammation. They also completed self-report measures of social media use, somatic symptoms, illness-related physician or health center visits, and whether they sought medical care for infection-related illnesses in the last 3 months. Social media use was positively correlated with higher levels of CRP, more somatic symptoms, and more visits to the doctor or health centers for an illness. Although directionally consistent, the correlation with likelihood of seeking medical care for infection-related illnesses was nonsignificant (p = 0.061). All of these results held after controlling for factors such as sociodemographic information and depressive symptoms. Given the prevalence of social media use in daily life, these findings underscore the need for more research examining how social media use relates to physical health.

Implementation intentions to express gratitude increase daily time co-present with an intimate partner, and moderate effects of variation in CD38.

Close social connections drive mental and physical health and promote longevity. Positive, other-focused behavior like expressing gratitude may be a key mechanism for increasing close bonds. Existing evidence consistent with this claim is predominantly correlational, likely driven by challenges in causally influencing and sustaining behavior change in the context of ongoing relationships. This 5-week field experiment with daily data from couples provides the first evidence for a brief, low-cost behavioral technique to increase everyday expressed gratitude to a romantic partner. Random assignment to the gratitude expression treatment (GET) increased the amount of time couples spent co-present in everyday life, from the weeks before GET to the weeks after, relative to the control condition. This effect was mediated by the change in expressed gratitude. Voluntary co-presence is an important behavioral indicator of close bonds in non-human animals. Further analyses with a functional genotype related to the oxytocin system (rs6449182) suggest a neurochemical pathway involved in the effects of expressing gratitude. Together, this evidence bridges animal and human research on bonding behavior and sets up future experiments on biopsychosocial mechanisms linking close bonds to health.