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Do inflammation and relational motivation coordinate having better sex? The interplay between C-reactive protein and relational motivation on sexual well-being
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Despite well-documented individual, relational, and health benefits, masturbation has been stigmatized and is understudied compared to partnered sex. In a US nationally representative survey of adults, we aimed to: (1) assess the prevalence and frequency of participants’ prior-year masturbation, (2) describe reasons people give for not masturbating, (3) describe reasons people give for masturbating, and (4) examine the association between masturbation frequency and actual/desired partnered sex frequency in the prior year. Significantly more men than women reported lifetime masturbation, past month masturbation, and greater masturbation frequency. The most frequently endorsed reasons for masturbating related to pleasure, feeling “horny,” stress relief, and relaxation. The most frequently endorsed reasons for not masturbating were lack of interest, being in a committed relationship, conflict with morals or values, or being against one’s religion. Among women, those who desired partnered sex much more often and a little more often were 3.89 times (95% CI: 2.98, 5.08) and 2.07 times (95% CI: 1.63, 2.62), respectively, more likely to report higher frequencies of past-year masturbation than those who desired no change in their partnered sex frequency. Among men, those who desired partnered sex much more often and a little more often were 4.40 times (95% CI: 3.41, 5.68) and 2.37 times (95% CI: 1.84, 3.06), respectively, more likely to report higher frequencies of past-year masturbation activity than those who reported that they desired no change in their current partnered sex frequency. Findings provide contemporary U.S. population-level data on patterns of adult masturbation.
Increased inflammation in major depressive disorder (MDD) has been associated with low functional connectivity (FC) in corticostriatal reward circuits and symptoms of anhedonia, relationships which may involve the impact of inflammation on synthesis and release of dopamine. To test this hypothesis while establishing a platform to examine target engagement of potential therapies in patients with increased inflammation, medically stable unmedicated adult MDD outpatients enrolled to have a range of inflammation (as indexed by plasma C-reactive protein [CRP] levels) were studied at two visits involving acute challenge with the dopamine precursor levodopa (L-DOPA; 250 mg) and placebo (double-blind, randomized order ~1-week apart). The primary outcome of resting-state (rs)FC in a classic ventral striatum to ventromedial prefrontal cortex reward circuit was calculated using a targeted, a priori approach. Data available both pre- and post-challenge (n = 31/40) established stability of rsFC across visits and determined CRP > 2 mg/L as a cut-point for patients exhibiting positive FC responses (post minus pre) to L-DOPA versus placebo (p < 0.01). Higher post-L-DOPA FC in patients with CRP > 2 mg/L was confirmed in all patients (n = 40) where rsFC data were available post-challenge (B = 0.15, p = 0.006), and in those with task-based (tb)FC during reward anticipation (B = 0.15, p = 0.013). While effort-based motivation outside the scanner positively correlated with rsFC independent of treatment or CRP, change in anhedonia scores negatively correlated with rsFC after L-DOPA only in patients with CRP > 2 mg/L (r = -0.56, p = 0.012). FC in reward circuitry should be further validated in larger samples as a biomarker of target engagement for potential treatments including dopaminergic agents in MDD patients with increased inflammation.
Background
Though many women report sexual arousal difficulties, the mechanisms driving these difficulties are unclear. Sexual response relies on a host of psychophysiological processes that have bidirectional relationships with inflammation. Additionally, chronic inflammation may impair genital blood flow, which in turn may impact sexual arousal. C-reactive protein (CRP) is an acute-phase marker of inflammation produced in response to cytokine signaling throughout the body, which makes it a useful marker of systemic inflammation.
Aim
The present study examined interactions between inflammation and women's sexual arousal.
Methods
CRP, self-reported frequency of partnered sexual activity, and subjective and vaginal arousal were assessed in 91 healthy, pre-menopausal women. Data were collected during a single laboratory session.
Main outcome measures
Subjective sexual arousal and vaginal pulse amplitude (a measure of vaginal arousal) were the main outcome measures.
Results
Change in subjective sexual arousal in response to a sexual film was unaffected by baseline CRP and sexual frequency. However, there were significant interactions between inflammation and sexual frequency in predicting vaginal arousal during the sexual film. Among women reporting more frequent sexual activity, higher CRP predicted lower magnitude arousal response and longer time to maximum vaginal arousal. Among women reporting less frequent sex, higher CRP predicted shorter time to maximum arousal and greater magnitude of arousal response. Controlling for cortisol strengthened the effects seen for time to maximum vaginal arousal but weakened those observed for percent change.
Conclusions
Among healthy young women, higher CRP may be associated with vaginal arousal, but not subjective sexual arousal. Specifically, our results suggest that higher baseline CRP is associated with lower genital sexual arousal for women who have sex frequently, which is consistent with clinical evidence that elevated inflammation can be detrimental to sexual function.
Decades of research in animals and humans show that inflammation is an important regulator of social behavior. While much research in this area has concluded that inflammation causes a withdrawal from social interaction, closer examination of the literature reveals that the effects of inflammation on social behavior are much more nuanced. Indeed, while many studies do show that increases in inflammation lead to social withdrawal, other studies show the exact opposite, finding that inflammation leads to an increase in social approach behavior. Critically, whether an organism withdraws or approaches when inflamed may depend on the whether the target of the behavior is a close other or a stranger. In the present paper, we review both animal research and our initial research in humans that has utilized experimental manipulations of inflammation and examined their effects on social approach behavior. We argue, based on complementary theoretical perspectives and supporting evidence from the literature, that there are three critical next steps for translational work examining the effects of inflammation on social behavior: (1) We need to study actual social behavior, as expressed toward both close others and strangers; (2) We should examine not just the social behavior of the inflamed individual, but also the behavior of others interacting with an inflamed individual; and (3) We must consider the relative increases in inflammation (i.e., higher vs. lower) as a contributor to social withdrawal vs. approach. Ultimately, we urge the field to move beyond a singular focus on inflammation and social withdrawal so that we can develop a more comprehensive understanding of the effects of inflammation on a variety of social behaviors.
Affectionate touch is an important behavior in close relationships throughout the lifespan. Research has investigated the relational and individual psychological and physical benefits of affectionate touch, but the situational factors that give rise to it have been overlooked. Theorizing from the interpersonal process model of intimacy, the current studies tested whether perceived partner responsiveness forecasts affectionate touch in romantic couples. Following a preliminary integrative data analysis ( N = 842), three prospective studies use ecologically valid behavioral (Studies 1 and 2) and daily (Studies 2 and 3) data, showing a positive association between perceived partner responsiveness and affectionate touch. Furthermore, in Study 3, we tested a theoretical extension of the interpersonal process of intimacy, finding that affectionate touch forecasts the partner’s perception of the touch-giver’s responsiveness the next day. Findings suggest affectionate touch may be an untested mechanism at the heart of the interpersonal process of intimacy.
In intimate relationships, greater social approach motivation is associated with a host of personal and relational benefits. Why is this the case? Although previous research suggests approach motivation primarily influences relational outcomes via increased exposure to positive relational events, in this research, based on approach-avoidance motivational theory, we revive the upward reactivity hypothesis, which suggests approach motivation upwardly enhances people's affective and relational experiences in response to positive social events. Specifically, we hypothesized that people with greater social approach motivation would react more positively to positively valenced interactions with their partner, and that this would occur even when accounting for their global levels of key outcomes. We tested these ideas across three studies. In all three studies, couples first reported their approach motivation toward the relationship, then engaged in a gratitude interaction. In Study 3, participants additionally engaged in a capitalization interaction, and provided nightly reports of positive relational events across the course of 14 days. We found robust support for the upward reactivity hypothesis: In lab-based interactions and in daily life, individuals with greater approach motivation reported enhanced outcomes in response to positive social events. We also found support for upward observability: When individuals were high in approach motivation, their partners observed them as experiencing greater positive emotion during the laboratory interactions. Moreover, we found evidence for upward crossover, as the upward reactivity experienced by people with greater approach motivation indirectly predicted enhanced partner outcomes. These results provide suggestive evidence that approach motivation can make already good relational moments extra sweet. (PsycInfo Database Record (c) 2020 APA, all rights reserved).
Purpose of Review
To describe the current state of research on interactions between inflammation and female sexual function.
Recent Findings
Inflammation may interfere with female sexual desire and arousal via direct (neural) and indirect (endocrine, vascular, social/behavioral) pathways. There are significant sex differences in the effect of inflammation on sexual function, arising from different evolutionary selection pressures on the regulation of reproduction. A variety of inflammation-related conditions are associated with the risk of female sexual dysfunction, including cardiovascular disease, metabolic syndrome, and chronic pain.
Summary
Clinical implications include the need for routine assessment for sexual dysfunction in patients with inflammation-related conditions, the potential for anti-inflammatory diets to improve sexual desire and arousal function, and consideration of chronic inflammation as moderator of sexual effects of hormonal treatments. Although the evidence points to a role for inflammation in the development and maintenance of female sexual dysfunction, the precise nature of these associations remains unclear.
Objective:
Social support and social integration have been linked to lower rates of morbidity and mortality. However, the biological mechanisms responsible for such links need greater attention to advance theory and unique intervention opportunities. The main aim of this article was to conduct a meta-analytic review of the association between social support-social integration and inflammatory cytokines (e.g., interleukin-6, C-reactive protein) and test several proposed moderators from prior qualitative reviews.
Method:
A literature search was conducted using the ancestry approach and with databases PsycINFO, Medline, and EMBASE by crossing the exact keywordssocial supportorsocial integrationwithinflammation. The review identified 41 studies with a total of 73,037 participants.
Results:
The omnibus meta-analysis showed that social support-social integration were significantly related to lower levels of inflammation (Zr = -.073). These results were not moderated by the operationalization of social relationships or the type of population, cytokine, and design.
Conclusions:
These data suggest that inflammation is at least one important biological mechanism linking social support and social integration to the development and course of disease. Future work should continue to build on this review and address next-generation questions regarding antecedent processes, mechanisms, and other potential moderators. (PsycINFO Database Record
Partners in romantic relationships differ in the extent to which they are oriented towards positive outcomes (e.g., intimacy) or away from negative outcomes (e.g., conflict). The present study examines these approach-avoidance relationship goals in relation to self-reported relationship problems, stress communication, and dyadic coping. Hypotheses were tested on a dyadic level (Actor-Partner Interdependence Model) using data from 368 couples. As expected, people endorsing approach goals reported fewer relationship problems, more effective stress communication, and better dyadic coping. People endorsing avoidance goals reported more relationship problems and poorer dyadic coping. Further, approach-oriented people tended to perceive their partner as being more communicative and more supportive, whereas avoidance-oriented people tended to perceive their partner as more communicative but less supportive. Reports by partners agreed with the self-reports of approach- and avoidance-oriented spouses concerning stress communication and dyadic coping. These findings highlight motivational factors in general, and orientation towards approach-avoidance goals in particular, as key features in understanding relationship maintenance.
Introduction:
Unemployment may represent a substantial source of psychosocial stress, and is linked to both increased risk of morbidity and mortality and adverse health-related behaviours. Few studies have examined the association of unemployment with systemic inflammation, a plausible mediator of the associations of psychosocial stress and health, and results are mixed and context dependent. This study examines the association of unemployment with C-reactive protein (CRP) and fibrinogen, two markers of systemic inflammation.
Methods:
A random-effects meta-analysis was performed using a multilevel modelling approach, including 12 national UK surveys of working-age participants in which CRP and fibrinogen were measured between 1998 and 2012 (N=30,037 economically active participants). The moderating impact of participant age and UK country was explored.
Results:
CRP and fibrinogen were elevated in unemployed compared to employed participants; jobseekers were also more likely (Odds Ratio: 1.39, p<0.001) to have CRP levels corresponding to high cardiovascular risk (>3mg/L), after adjustment for age, gender, education, long-term illness, smoking, and body mass index. Associations were not explained by mental health. Associations peaked in middle-age, and were stronger in Scotland and Wales than in England.
Conclusions:
Our study demonstrates that systemic inflammation is associated with an important but little-studied aspect of the social environment, as it is elevated in unemployed compared to employed survey participants. Modifications suggest the association of unemployment and inflammation is substantially influenced by contextual factors, and may be especially strong in Wales, where further investigation of this relationship is needed.
There is a notable gap between heterosexual men and women in frequency of orgasm during sex. Little is known, however, about sexual orientation differences in orgasm frequency. We examined how over 30 different traits or behaviors were associated with frequency of orgasm when sexually intimate during the past month. We analyzed a large US sample of adults (N = 52,588) who identified as heterosexual men (n = 26,032), gay men (n = 452), bisexual men (n = 550), lesbian women (n = 340), bisexual women (n = 1112), and heterosexual women (n = 24,102). Heterosexual men were most likely to say they usually-always orgasmed when sexually intimate (95%), followed by gay men (89%), bisexual men (88%), lesbian women (86%), bisexual women (66%), and heterosexual women (65%). Compared to women who orgasmed less frequently, women who orgasmed more frequently were more likely to: receive more oral sex, have longer duration of last sex, be more satisfied with their relationship, ask for what they want in bed, praise their partner for something they did in bed, call/email to tease about doing something sexual, wear sexy lingerie, try new sexual positions, anal stimulation, act out fantasies, incorporate sexy talk, and express love during sex. Women were more likely to orgasm if their last sexual encounter included deep kissing, manual genital stimulation, and/or oral sex in addition to vaginal intercourse. We consider sociocultural and evolutionary explanations for these orgasm gaps. The results suggest a variety of behaviors couples can try to increase orgasm frequency.
Inflammation-induced sickness is associated with a large set of behavioral alterations, but its motivational aspects remain poorly explored in humans. The present study assessed the effect of lipopolysaccharide (LPS) administration at a dose of 2 ng/kg of body weight on motivation in twenty-one healthy human subjects, in a double-blinded, placebo (saline)-controlled, cross-over design. Incentive motivation and reward sensitivity were measured using the Effort Expenditure for Rewards Task (EEfRT), in which motivation for high-effort/high-reward trials versus low-effort/low-reward trials are manipulated by variations in reward magnitude and probability to win. Because of the strong interactions between sleepiness and motivation, the role of sleepiness was also determined. As expected, the probability to win predicted the choice to engage in high-effort/high-reward trials, but this occurred at a greater extent after LPS than after saline administration. This effect was related to the level of sleepiness. Sleepiness increased motivation to choose the high-effort/high-reward mode of response, but only when the probability to win was the highest. LPS had no effect on reward sensitivity either directly or via sleepiness. These results indicate that systemic inflammation induced by LPS administration causes motivational changes in young healthy subjects, which are associated with sleepiness. Thus, despite its association with energy saving behaviors, sickness allows increased incentive motivation when the effort is deemed worthwhile.Neuropsychopharmacology accepted article preview online, 13 September 2016. doi:10.1038/npp.2016.191.
Passion and sexual satisfaction typically diminish in longer-term relationships, but this decline is not inevitable. We identified the attitudes and behaviors that most strongly differentiated sexually satisfied from dissatisfied men and women who had been together for at least three years (N = 38,747). Data were collected in 2006 from cohabiting and married men (M) and women (W) via an online survey on a major national U.S. news Web site. The vast majority of these participants reported being satisfied with their sex lives during their first six months together (83% W; 83% M). Satisfaction with their current sex lives was more variable, with approximately half of participants reporting overall satisfaction (55% W; 43% M) and the rest feeling neutral (18% W; 16% M) or dissatisfied (27% W; 41% M). More than one in three respondents (38% W; 32% M) claimed their sex lives were as passionate now as in the beginning. Sexual satisfaction and maintenance of passion were higher among people who had sex most frequently, received more oral sex, had more consistent orgasms, and incorporated more variety of sexual acts, mood setting, and sexual communication. We discuss implications of these findings for research and for helping people revitalize their sex lives.
Crosstalk between inflammatory pathways and neurocircuits in the brain can lead to behavioural responses, such as avoidance and alarm, that are likely to have provided early humans with an evolutionary advantage in their interactions with pathogens and predators. However, in modern times, such interactions between inflammation and the brain appear to drive the development of depression and may contribute to non-responsiveness to current antidepressant therapies. Recent data have elucidated the mechanisms by which the innate and adaptive immune systems interact with neurotransmitters and neurocircuits to influence the risk for depression. Here, we detail our current understanding of these pathways and discuss the therapeutic potential of targeting the immune system to treat depression.
Background and objectives:
We examined a mechanism that may coordinate trade-offs between reproduction and immune response in healthy women, namely, changes in inflammation across the ovarian cycle.
Methodology:
We investigated C-reactive protein (CRP), an inflammation marker, across two consecutive ovarian cycles in 61 Bolivian women. Participants provided saliva samples every other day, and dried blood spots on 5-6 days spread across weeks 2-3 of each cycle. Cycles were characterized as ovulatory/anovulatory based on profiles of reproductive hormones. Participants also reported whether they were sexually partnered with a male or sexually abstinent during the study.
Results:
High early-cycle, but not late-cycle, CRP was associated with anovulation. High inflammation at the end of one cycle was not associated with anovulation in the subsequent cycle. Among ovulatory cycles, women with sexual partners had significantly lower CRP at midcycle, and higher CRP at follicular and luteal phases; in contrast, sexually abstinent women had little cycle-related change in CRP. In anovulatory cycles, partnership had no effect on CRP. CRP varied significantly with socioeconomic status (higher in better-off than in poorer women).
Conclusions and implications:
These findings suggest that the cycle-specific effect of inflammation on ovarian function may be a flexible, adaptive mechanism for managing trade-offs between reproduction and immunity. Sociosexual behavior may moderate changes in inflammation across the ovarian cycle, suggesting that these shifts represent evolved mechanisms to manage the trade-offs between reproduction and immunity. Clinically, these findings support considering both menstrual cycle phase and sexual activity in evaluations of pre-menopausal women's CRP concentrations.
Childhood trauma confers higher risk of adulthood physical and mental illness; however, the biological mechanism mediating this association remains largely unknown. Recent research has suggested dysregulation of the immune system as a possible biological mediator. The present paper conducted a meta-analysis to establish whether early-life adversity contributes to potentially pathogenic pro-inflammatory phenotypes in adult individuals. A systematic search of Pubmed, PsycINFO, EMBASE, Scopus and Medline identified 25 articles for the meta-analysis, including 18 studies encompassing a sample of 16 870 individuals for C-reactive protein (CRP), 15 studies including 3751 individuals for interleukin-6 (IL-6) and 10 studies including 881 individuals for tumour necrosis factor-α (TNF-α). Random-effects meta-analysis showed that individuals exposed to childhood trauma had significantly elevated baseline peripheral levels of CRP (Fisher's z=0.10, 95% confidence interval (CI)=0.05-0.14), IL-6 (z=0.08, 95% CI=0.03-0.14) and TNF-α (z=0.23, 95% CI=0.14-0.32). Subgroup analyses for specific types of trauma (sexual, physical or emotional abuse) revealed that these impact differentially the single inflammatory markers. Moreover, meta-regression revealed greater effect sizes in clinical samples for the association between childhood trauma and CRP but not for IL-6 or TNF-α. Age, body mass index (BMI) and gender had no moderating effects. The analysis demonstrates that childhood trauma contributes to a pro-inflammatory state in adulthood, with specific inflammatory profiles depending on the specific type of trauma.Molecular Psychiatry advance online publication, 2 June 2015; doi:10.1038/mp.2015.67.
Maximum likelihood or restricted maximum likelihood (REML) estimates of the
parameters in linear mixed-effects models can be determined using the lmer
function in the lme4 package for R. As for most model-fitting functions in R,
the model is described in an lmer call by a formula, in this case including
both fixed- and random-effects terms. The formula and data together determine a
numerical representation of the model from which the profiled deviance or the
profiled REML criterion can be evaluated as a function of some of the model
parameters. The appropriate criterion is optimized, using one of the
constrained optimization functions in R, to provide the parameter estimates. We
describe the structure of the model, the steps in evaluating the profiled
deviance or REML criterion, and the structure of classes or types that
represents such a model. Sufficient detail is included to allow specialization
of these structures by users who wish to write functions to fit specialized
linear mixed models, such as models incorporating pedigrees or smoothing
splines, that are not easily expressible in the formula language used by lmer.
During pathogen exposure or some forms of stress, proinflammatory processes induce an array of motivated and behavioral adjustments termed "sickness behaviors". Although withdrawal from social interactions is a commonly observed sickness behavior, the relation between social behavior and sickness is much more complex. Sickness can suppress or stimulate social behavior. Sickness can serve as a social cue. Stressors that are social in nature can induce sickness behaviors, and sickness behavior can be readily suppressed by meaningful social stimuli. The nature, context, and timing of these effects together suggest that cytokine-induced behavior may play a role in mediating social interactions in various non-pathological conditions.
Two studies leading to the development of a short form of the Social Support Questionnaire (SSQ) are reported. In Study 1 three items selected for high correlations with the total score (SSQ3) were administered to 182 university students together with several personality measures. SSQ3 had acceptable test-retest reliability and correlations with personality variables similar to those of the SSQ. Internal reliability was marginal although acceptable for an instrument with so few items. Study 2 employed three sets of data in developing a six-item instrument (SSQ6). The SSQ6 had high internal reliability and correlated highly with the SSQ and similarly to it with personality variables. The research findings accompanying the development of the short form social support measure suggest that perceived social support in adults may be a reflection of early attachment experience.
Prior research found that lower sexual frequency and satisfaction were associated with higher rates of divorce, but little research had examined the role of sexual activity in the dissolution of cohabiting unions. We drew upon social exchange theory to hypothesize why sexual frequency is more important in cohabitation: (a) cohabitors' lower costs of finding sexual alternatives, (b) cohabitors' lower barriers to ending the relationship in the form of union-specific economic and noneconomic capital, and (c) cohabitors' higher expectations for sexual activity. Using the National Survey of Families and Households (N = 5,902), we examined the relationship between sexual frequency and union dissolution. Results indicated that low sexual frequency was associated with significantly higher rates of union dissolution among cohabitors than married couples.
A construct consisting of eight dispositional sexual motives was proposed to expand upon and integrate earlier theory and research. The eight motives are desire for (a) feeling valued by one's partner, (b) showing value for one's partner, (c) obtaining relief from stress, (d) providing nurturance to one's partner, (e) enhancing feelings of personal power, (f) experiencing the power of one's partner, (g) experiencing pleasure, and (h) procreating. Based on this formulation, a self‐report questionnaire was developed to measure stable interest in the eight incentives hypothesized to influence sexual motivation and behavior. Initial factor analyses supported the proposed model in that items clustered predominantly into the theoretically proposed dimensions. The questionnaire was revised, and two subsequent factor analyses supported the earlier factor structure. AMORE scales were moderately correlated with erotophobic versus erotophilic attitudes, attitudes about uncommitted sex, sensation‐seeking tendencies, and need for attention. The Value For Partner and Nurturance scales were correlated with a personality measure of interpersonal warmth, and the Power and Partner Power scales were correlated with aggression tendencies. All AMORE scales were correlated with a measure of general sexual desire. Many AMORE scales were also correlated with self‐reports of sexual behavior and contraception/protection use. The distinction among sexual motives provides a more complete understanding of sexual motivation and is likely to improve prediction of sexual behavior.
Recent theory posits that the emotion of gratitude uniquely functions to build a high-quality relationship between a grateful person and the target of his or her gratitude, that is, the person who performed a kind action (Algoe et al., 2008). Therefore, gratitude is a prime candidate for testing the dyadic question of whether one person's grateful emotion has consequences for the other half of the relational unit, the person who is the target of that gratitude. The current study tests the critical hypothesis that being the target of gratitude forecasts one's relational growth with the person who expresses gratitude. The study employed a novel behavioral task in which members of romantic relationships expressed gratitude to one another in a laboratory paradigm. As predicted, the target's greater perceptions of the expresser's responsiveness after the interaction significantly predicted improvements in relationship quality over 6 months. These effects were independent from perceptions of responsiveness following two other types of relationally important and emotionally evocative social interactions in the lab, suggesting the unique weight that gratitude carries in cultivating social bonds. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
Neuroimaging studies in humans have demonstrated that inflammatory cytokines target basal ganglia function and presynaptic dopamine (DA), leading to symptoms of depression. Cytokine-treated nonhuman primates also exhibit evidence of altered DA metabolism in association with depressive-like behaviors. To further examine cytokine effects on striatal DA function, eight rhesus monkeys (four male, four female) were administered interferon (IFN)-α (20 MIU/m2 s.c.) or saline for 4 weeks. In vivo microdialysis was used to investigate IFN-α effects on DA release in the striatum. In addition, positron emission tomography (PET) with [11C]raclopride was used to examine IFN-α-induced changes in DA2 receptor (D2R) binding potential before and after intravenous amphetamine administration. DA transporter binding was measured by PET using [18F]2β-carbomethoxy-3β-(4- chlorophenyl)-8-(2-fluoroethyl)nortropane. Anhedonialike behavior (sucrose consumption) was assessed during saline and IFN-α administration. In vivo microdialysis demonstrated decreased release of DA after 4 weeks of IFN-α administration compared with saline. PET neuroimaging also revealed decreased DA release after 4 weeks of IFN-α as evidenced by reduced displacement of [11C]raclopride following amphetamine administration. In addition, 4 weeks of IFN-α was associated with decreased D2R binding but no change in the DA transporter. Sucrose consumption was reduced during IFN-α administration and was correlated with decreased DA release at 4 weeks as measured by in vivo microdialysis. Taken together, these findings indicate that chronic peripheral IFN-α exposure reduces striatal DA release in association with anhedonia-like behavior in nonhuman primates. Future studies examining the mechanisms of cytokine effects on DA release and potential therapeutic strategies to reverse these changes are warranted. © 2013 American College of Neuropsychopharmacology. All rights reserved.
Introduction:
C-reactive protein (CRP) is an acute-phase reactant with an increasing number of clinical functions. Studies in recent years have identified several social, economic, demographic, and psychological factors that contribute to baseline inflammation. Psychosocial stress represents a significant contributor to baseline inflammation. Given the importance of understanding background drivers of CRP levels, we conducted this review to assess the impact of chronic psychosocial stress on CRP levels.
Methods:
Medline was searched through February 2013 for human studies examining CRP levels with respect to chronic psychosocial stress.
Results:
The initial search identified 587 articles from which 129 potentially appropriate articles were reviewed. Of these 129 articles, 41 articles were included in the review. These studies were published between 2003 and 2013. Of these studies, 6 analyzed employment stress, 2 analyzed unemployment stress, 6 analyzed burnout and vital exhaustion, 6 analyzed caregiver stress, 3 analyzed interpersonal stress, 17 analyzed socioeconomic position, and 2 analyzed discrimination.
Conclusion:
We conclude that psychosocial stress significantly impacts CRP and should be considered when interpreting the meaning of CRP elevations.
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.
We do not know what happens in initial interactions to spark platonic or romantic relationships. This requires data on relationships from their inception, tracked over time. Building on theory about relationship promotion, we identified three exemplar behaviors to test novel hypotheses about relationship development. When starting college, a greenhouse for relationship initiation, first-year undergraduates ( N = 143) reported initial interactions with potential friends and romantic partners, and then 129 of them reported back about those 591 people over the semester. As predicted, reports of each behavior—affectionate touch, shared laughter, and partner’s gratitude expression—were associated with immediate interest in affiliating with the new person, beyond their perceived warmth, competence, and attractiveness; theoretically derived social perceptual mechanisms explained these links. Critically, although not all potential connections blossomed into relationships, these behavioral precursors to relationship promotion predicted relationship development via post-interaction interest in affiliating. Findings are contextualized within attraction literature with implications for relationship development.
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 hours, 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.
Inadequate response to antidepressant treatment, in a significant proportion of patients diagnosed with Major Depressive Disorder, contributes to the large burden of disability associated with the disease; thus, predicting treatment response is one of the most important challenge for clinicians who deal with depressed patients. The cytokine hypothesis of depression suggests that altered pheripheral cytokine levels are involved in the pathophysiology of depressive disorder and in modulating response to treatment. Present meta-analysis aimed to investigate the association between cytokine levels at baseline and response to antidepressant therapies. Authors performed a systematic search of PubMed and Embase databases for studies published between 2010 and January 2021: of 3345 identified records, 31 studies met the inclusion criteria for the qualitative synthesis, whereas 19 studies were eligible for quantitative analysis. Patients who failed to respond to antidepressant had aberrant inflammatory process, namely higher baseline levels of C-Reactive Protein and Interleukine-8, which is associated with treatment outcome in Major Depressive Disorder. Despite these promising results, further investigations are needed in order to replicate the data and to examine the potential role of inflammatory marker as a novel predictive tool for pharmacological treatment of depressive disorder.
Recent social psychoneuroimmunology models suggest bidirectional associations between social experiences and the immune system. This work posits that social relationships and networks may influence the functioning of the immune system, but we know little about the role that the immune system plays in how social networks are created and maintained. We examine how salivary C-reactive protein (CRP), as an inflammatory protein, is associated with making new and keeping existing friendship and conflicted relationships among young adult members of a social group. Participants (n = 37; 67.6% female; M age = 18.18 years, 56.81% white/non-Hispanic) provided nominations of friends and individuals with whom they have conflict at wave 1 and two months later at wave 2. At wave 1, in a group setting, participants donated saliva, later assayed for CRP. Stochastic actor-based models revealed that CRP levels were negatively associated with keeping existing friends and positively associated with developing new friendships. We also found that CRP levels were negatively associated with creating new conflicted relationships and predicted an increased likelihood that group members continue conflicted relationships with the focal individual. These preliminary results support the premises of recent social psychoneuroimmunology models by suggesting that inflammation can also serve as a signal to seek new supportive relationships such as friendships and avoid creating new relationships characterized by threat and/or conflict. Findings provide new insights into the theorized function of the immune system for social approach and withdrawal patterns through which our social connections are constructed.
Recent evidence suggests differential patterns of social behavior following an inflammatory challenge, such that increases in inflammation may not uniformly lead to social withdrawal. Indeed, increases in inflammation have been associated with enhanced self-reported motivation to approach a specific close other, and greater neural sensitivity to positive social cues. However, no known studies have examined the association between inflammation in response to an inflammatory challenge and social behavior in humans, nor has past research examined specifically how approach and withdrawal behavior may differ based on whether the target is a close other or stranger. To address this, 31 participants (ages 18-24) received the influenza vaccine to elicit a low-grade inflammatory response. The morning before and approximately 24 hours after the vaccine, participants provided a blood sample and completed a computer task assessing automatic (implicit) approach and withdrawal behavior toward a specific close other and strangers. Greater increases in the inflammatory cytokine interleukin-6 (IL-6) in response to the vaccine were associated with an increase in accuracy in avoiding strangers and a decrease in accuracy in approaching them. Increases in IL-6 were also associated with a decrease in reaction time to approach a close other, but only when controlling for baseline IL-6 levels. There were no associations between change in IL-6 and changes in self-reported motivation to engage in social behavior with either close others, or strangers. Together, these findings reveal that increases in inflammation following the influenza vaccine are associated with automatic social behavior, especially behavior suggesting avoidance of unfamiliar social targets and ease in approaching close others. These data add to the growing literature suggesting that the association between inflammation and social behavior includes both social withdrawal and social approach, depending on the specific target.
Patients with depressive disorders show a wide range of clinical manifestations including cognitive and neurovegetative symptoms. Importantly, these symptoms can differ in terms of biological etiology, and deconstructing depression into specific symptoms may provide valuable insight into the underlying neurobiology. Little research has examined inflammation in the context of depressive dimensions. Here we conduct a narrative review of the existing literature (21 studies) to elucidate whether the depression-inflammation link is symptom specific. Overall, there is evidence that an association exists between neurovegetative symptoms of depression and inflammation, independent of cognitive symptoms. The same cannot be said of cognitive symptoms and inflammation. There is also some evidence of gender differences in the directionality of the relationship between depression and inflammation. Potential explanations for these findings, limitations of the existing literature and recommendations for future research design are discussed.
Introduction:
Male and female sexual dysfunction (SD) is considered a multifactorial condition. Numerous studies have shown the involvement of inflammatory processes in this pathological condition. Sexual intercourse requires healthy and functioning vessels to supply the pelvic region in both males and females, generating penile erection and clitoral and vaginal lubrication, respectively. Cardiovascular diseases and associated risk factors may contribute negatively to pelvic blood flow, possibly through immune system activation.
Aim:
The study aimed to address the correlation between vascular inflammation driven by immune system activation and SD in males and females.
Methods:
A literature review was performed to identify articles addressing male and female SD and vascular inflammation. Key words included "male and female sexual dysfunction," "vascular inflammation," "iliac and pudendal arteries dysfunction," "genitourinary tract," and "blood flow."
Main outcome measures:
Management of systemic and local inflammation may be a useful alternative to improve SD and reduce the risk of cardiovascular diseases in the future.
Results:
Increased levels of cytokines and chemokines have been detected in humans and animals with hypertension, obesity, and diabetic conditions. Chronic activation of the innate immune system, especially by pathogen- or damage-associated molecular patterns, and metabolic-related disorders may act as triggers further contributing to an increased inflammatory condition. Due to the reduced size of vessels, SD and retinal vascular impairments have been shown to be predictive factors for cardiovascular diseases. Therefore, considering that blood flow to the genitalia is essential for sexual function, endothelial dysfunction and vascular remodeling, secondary to chronic immune system activation, may be implicated in male and female vasculogenic SD.
Conclusions:
Several conditions appear to play a role in SD. In the present review, we have identified a role for the immune system in generating vascular and tissue impairments contributing to erectile dysfunction and female SD. Calmasini FB, Klee N, Webb RC, et al. Impact of Immune System Activation and Vascular Impairment on Male and Female Sexual Dysfunction. Sex Med Rev 2019;7:604-613.
Depression is linked to deficits in cognitive control and a host of other cognitive impairments arise as a consequence of these deficits. Despite of their important role in depression, there are no mechanistic models of cognitive control deficits in depression. In this paper we propose how these deficits can emerge from the interaction between motivational and cognitive processes. We review depression-related impairments in key components of motivation along with new cognitive neuroscience models that focus on the role of motivation in the decision-making about cognitive control allocation. Based on this review we propose a unifying framework which connects motivational and cognitive control deficits in depression. This framework is rooted in computational models of cognitive control and offers a mechanistic understanding of cognitive control deficits in depression.
Good relationships are characterized by frequent positive social interactions, such as having fun together, sharing laughs, doing kind things for one another, and expressing gratitude. Here, building on rapidly emerging findings, I articulate core features of positive interpersonal processes for the first time. This approach leads to useful specificity in predictions about relationship consequences and simultaneously contributes to both affective and relationship science, two domains that span disciplines within the psychological literature. In turn, basic research on everyday positive interpersonal processes points toward new avenues for understanding the well-established links between good relationships and health.
Past research has found menstrual-cycle-related changes in functional immune response; we examined if sexual activity also changed markers of immune defense. We followed 32 naturally cycling women (15 sexually active with a partner ≥ 1 time/week, 17 sexually abstinent for the last four months) over one menstrual cycle. Participants provided serum and saliva samples at menses and ovulation, and additional saliva samples at midfollicular and midluteal phases. At each phase, participants also self-reported symptoms associated with colds, flu, pain, menstrual discomfort, and premenstrual syndrome. We tested saliva and serum for ability to kill Escherichia coli or Candida albicans, and serum for complement protein activity. For serum-mediated pathogen killing, among sexually active women only, there was a significant midcycle decrease in killing of E. coli. For saliva-mediated pathogen killing, among abstinent women only, there was a significant midcycle decrease in killing of E. coli, and midcycle increase in killing of C. albicans. Sexually active women had significantly lower complement activity than abstinent women overall. Finally, both groups reported lower physical symptoms at midcycle and higher symptoms at menses. There may be important differences in immune function between healthy women who are sexually active versus abstinent. Further replication is warranted.
Introduction:
Major Depressive Disorder (MDD) in accordance to the inflammatory concept is associated with complex immunological disturbances in the central nervous system (CNS). This is reflected by elevated plasma levels of inflammatory cytokines in depressed subjects. Although numerous studies report significant influence of antidepressants on pro-inflammatory/anti-inflammatory cytokines balance, the available data is often inconsistent regarding specific cytokines and drugs used. We aimed to perform a comprehensive meta-analysis of the effect of antidepressant treatment on a wide array of cytokines.
Methods:
We performed a systematic search of 6 databases, which yielded 32 studies measuring the levels of selected cytokines before and at a second time-point during antidepressant treatment. For meta-analysis of selected studies with a continuous measure we analysed variables containing the number of cases, mean and standard deviation of the level of IL-1ß, IL-2, IL-5, IL-6, IL-8, IL-10, CRP, TNF-α, IFN-γ levels observed in the different studies, in the intervention groups before and after antidepressant treatment.
Results:
Statistical analysis revealed significant decreases of IL-4, IL-6, and IL-10 in MDD subjects after antidepressant treatment. In case of IL-1ß the decrease was significant exclusively for SSRI drugs. We did not find any significant effect of antidepressant medication on IL-2, TNF-α IFN-γ and CRP.
Conclusions:
Antidepressant treatment affects the levels of cytokines in depression. The immunological imbalance in MDD is complex and seems to be mediated by other factors yet to be elucidated. The credibility of our results is limited by high heterogeneity among studies and very few studies with a placebo-controlled design. Research with MDD subtypes, response to treatment status and cytokine associations with the kynurenine pathway taken into account pose a promising target for future studies.
Introduction:
This study investigates social determinants of systemic inflammation, focusing on race, SES, and perceived discrimination.
Methods:
Data on 884 white and 170 black participants were obtained from the Survey of Midlife in the U.S., a cross-sectional observational study combining survey measures, anthropometry, and biomarker assay. Data, collected in 2004-2009, were analyzed in 2016. Main outcome measures were fasting blood concentrations of C-reactive protein, interleukin 6, fibrinogen, and E-selectin. For each biomarker, series of multivariate linear regression models were estimated for the pooled sample and separately for blacks and whites. Full models included social determinants; psychological, lifestyle, and health factors; and demographic covariates.
Results:
Bivariate analyses indicated higher concentrations of all inflammation markers among blacks compared with whites (p<0.001). In fully adjusted models using the pooled sample, racial differences persisted for interleukin 6 (p<0.001) and fibrinogen (p<0.01). For E-selectin and C-reactive protein, racial differences were explained after adjusting for covariates. Education was linked to lower fibrinogen concentration (p<0.05) in the fully adjusted model and C-reactive protein concentration (p<0.01) after adjusting for demographic factors and income. Lifetime perceived discrimination was related to higher concentrations of fibrinogen (p<0.05) in the fully adjusted model, and higher concentrations of E-selectin and interleukin 6 (p<0.05) after adjusting for socioeconomic status (SES) and demographic factors.
Conclusions:
This study clarifies the contributions of race, SES, and perceived discrimination to inflammation. It suggests that inflammation-reducing interventions should focus on blacks and individuals facing socioeconomic disadvantages, especially low education.
Objective:
To examine differences in inflammation markers in sexually active versus abstinent women and observe changes in inflammation markers across the menstrual cycle. Cycle-related immune fluctuations may have evolved to reduce interference with conception. If so, reproductively active (i.e., sexually active) women should show the most variability in cytokine expression.
Design:
Participants provided serum samples at menses and ovulation (from which cytokines were assayed) and saliva samples at menses and during follicular, ovulation, and luteal phases (from which C-reactive protein [CRP] was assayed). Participants self-reported intercourse frequency during the study.
Setting:
Academic research laboratory.
Patient(s):
Thirty-two healthy, naturally cycling premenopausal women (sexually active, n = 15; abstinent, n = 17).
Intervention(s):
Observational study.
Main outcome measure(s):
Levels of proinflammatory cytokines (interleukin-6 [IL-6], interferon γ [IFN-γ], tumor necrosis factor-α [TNF-α]), an anti-inflammatory cytokine (interleukin-4 [IL-4]), and a marker of total inflammation (CRP).
Result(s):
Sexually active women had higher levels of all of the immune markers measured, including both pro- and anti-inflammatory cytokines, than abstinent women. Relative to sexually active women, abstinent women had less change across the menstrual cycle in levels of CRP. Among sexually active women, higher intercourse frequency predicted greater midcycle decreases in CRP, IL-6, and IFN-γ and midcycle increases in IL-4.
Conclusion(s):
Sexual activity may stimulate a complex interaction between pro- and anti-inflammatory cytokines that subsequently drives midcycle declines in inflammation.
Inflammation plays a critical role in the pathophysiology of cardiovascular disease (CVD) and levels of circulating inflammatory markers are associated with future CVD risk. However, the physiological mechanisms that control systemic levels of circulating inflammatory markers are not well understood. Here, we explore possible autonomic nervous system mechanisms by testing whether resting and stressor-evoked cardiovascular responses are associated with two markers of systemic inflammation: interleukin(IL)-6 and C-reactive protein (CRP). Subjects were 159 Black and 129 White men (M = 33.0 years) who completed a laboratory protocol including an anger recall speech task. Electrocardiography and impedance cardiography data were collected during a resting baseline, the speech task, and a final recovery period. Hierarchical regressions tested whether resting or stressor-evoked levels of heart rate (HR), high-frequency heart rate variability (HF-HRV), pre-ejection period (PEP), and pulse transit time (PTT) were associated with CRP or IL-6. Higher resting HR was associated with higher CRP (β = .19, p = .003) and IL-6 (β = .13, p < .05). Similarly, shorter resting PTT was associated with higher CRP (β = -.21, p < .001) and IL-6 (β = -.14, p = .02). In addition, greater stressor-evoked decreases in HF-HRV were associated with higher CRP (β = -.14, p = .01). Associations were independent of age, race, body mass index (BMI), smoking behavior, and socioeconomic status. Resting HF-HRV and PEP were also associated with CRP and IL-6, but associations were not significant after controlling for BMI and smoking behavior. These findings indicate that resting HR and PTT, as well stressor-evoked HF-HRV reactivity, are associated with systemic inflammation. Our results suggest that both tonic and stressor-evoked sympathetic and parasympathetic nervous system activity may contribute to regulation of systemic inflammation.
Although it has commonly been assumed that the immune system and the processes that govern social behavior are separate, non-communicating entities, research over the past several decades suggests otherwise. Thus, considerable evidence now shows that inflammatory processes and social behavior are actually powerful regulators of one another. This review first summarizes evidence that inflammatory processes regulate social behavior, leading to characteristic changes that may help an individual navigate the social environment during times of sickness. Specifically, this review shows that inflammation: 1) increases threat-related neural sensitivity to negative social experiences (eg, rejection, negative social feedback), presumably to enhance sensitivity to threats to well-being or safety in order to avoid them and 2) enhances reward-related neural sensitivity to positive social experiences (eg, viewing close others, receiving positive social feedback), presumably to increase approach-related motivation towards others who might provide support and care during sickness. Next, this review summarizes evidence showing that social behavior also regulates aspects of inflammatory activity, preparing the body for situations in which wounding and infection may be more likely (social isolation). Here, we review research showing: 1) that exposure to social stressors increases proinflammatory activity, 2) that individuals who are more socially isolated (ie, lonely) show increased proinflammatory activity, and 3) that individuals who are more socially isolated show increased proinflammatory activity in response to an inflammatory challenge or social stressor. The implications of the co-regulation of inflammation and social behavior are discussed.Neuropsychopharmacology accepted article preview online, 02 August 2016. doi:10.1038/npp.2016.141.
Throughout the life span, individuals engage in affectionate touch with close others. Touch receipt promotes well-being in infancy, but the impacts of touch in adult close relationships have been largely unexplored. In this article, we propose that affectionate touch receipt promotes relational, psychological, and physical well-being in adulthood, and we present a theoretical mechanistic model to explain why affectionate touch may promote these outcomes. The model includes pathways through which touch could affect well-being by reducing stress and by promoting well-being independent of stress. Specifically, two immediate outcomes of affectionate touch receipt—relational-cognitive changes and neurobiological changes—are described as important mechanisms underlying the effects of affectionate touch on well-being. We also review and evaluate the existing research linking affectionate touch to well-being in adulthood and propose an agenda to advance research in this area. This theoretical perspective provides a foundation for future work on touch in adult close relationships.
Previous correlational research has demonstrated an association between people's reasons for having sex (i.e., their sexual goals) and their sexual desire and sexual and relationship satisfaction. Across two studies of people in romantic relationships (N = 396) we extend previous research and demonstrate, for the first time, that manipulating the salience of approach sexual goals (i.e., engaging in sex to pursue positive outcomes, such as enhanced intimacy) compared to avoidance sexual goals (i.e., engaging in sex to avert negative outcomes, such as a partner's disappointment) or a control condition leads people to feel higher sexual desire for their romantic partners and to report higher sexual and relationship satisfaction. In addition, in Study 2 we demonstrate that focusing on approach sexual goals over the course of a week leads people to report more satisfying sexual experiences during that week, as well as higher desire and overall relationship satisfaction, compared to a control group. The current findings advance approach-avoidance theory by providing evidence that it is possible to manipulate people's sexual goals and, in turn, impact their feelings of desire and satisfaction. Results are promising for the development of interventions to promote sexual and relational well-being.
Laughter is a pervasive human behavior that most frequently happens in a social context. However, data linking the behavior of laughter with psychological or social outcomes are exceptionally rare. Here, the authors draw attention to shared laughter as a useful objective marker of relationship well-being. Spontaneously generated laughs of 71 heterosexual romantic couples were coded from a videorecorded conversation about how the couple first met. Multilevel models revealed that while controlling for all other laughter present, the proportion of the conversation spent laughing simultaneously with the romantic partner was uniquely positively associated with global evaluations of relationship quality, closeness, and social support. Results are discussed with respect to methodological considerations and theoretical implications for relationships and behavioral research more broadly.
Although considerable research has shown that inflammation leads to social withdrawal more generally, it is also possible that inflammation leads to social approach when it comes to close others. Whereas it may be adaptive to withdraw from strangers when sick, it may be beneficial to seek out close others for assistance, protection, or care when sick. However, this possibility has never been explored in humans nor have the neural substrates of these behavioral changes. Based on the role of the ventral striatum (VS) in responding to: (1) the anticipation of and motivation to approach rewarding outcomes and (2) viewing social support figures, the VS may also be involved in sickness-induced approach toward support figures. Thus, the goal of the present study was to examine whether inflammation leads to a greater desire to approach support figures and greater VS activity to viewing support figures. To examine this, 63 participants received either placebo or low-dose endotoxin, which safely triggers an inflammatory response. Participants reported how much they desired to be around a self-identified support figure, and viewed pictures of that support figure while undergoing an fMRI scan to assess reward-related neural activity. In line with hypotheses, endotoxin (vs. placebo) led participants to report a greater desire to be around their support figure. In addition, endotoxin (vs. placebo) led to greater VS activity to images of support figures (vs. strangers), and greater increases in inflammation (IL-6 levels) were associated with greater increases in VS activity. Together, these results reveal a possible neural mechanism important for sickness-induced social approach and highlight the need for a more nuanced view of changes in social behavior during sickness.
Psychological stress is implicated in the etiology of many common chronic diseases and mental health disorders. Recent research suggests that inflammation may be a key biological mediator linking stress and health. Nevertheless, the neurocognitive pathways underlying stress-related increases in inflammatory activity are largely unknown. The present study thus examined associations between neural and inflammatory responses to an acute laboratory-based social stressor. Healthy female participants (n = 31) were exposed to a brief episode of stress while they underwent an fMRI scan. Blood samples were taken before and after the stressor, and plasma was assayed for markers of inflammatory activity. Exposure to the stressor was associated with significant increases in feelings of social evaluation and rejection, and with increases in levels of inflammation. Analyses linking the neural and inflammatory data revealed that heightened neural activity in the amygdala in response to the stressor was associated with greater increases in inflammation. Functional connectivity analyses indicated that individuals who showed stronger coupling between the amygdala and the dorsomedial prefrontal cortex (DMPFC) also showed a heightened inflammatory response to the stressor. Interestingly, activity in a different set of neural regions was related to increases in feelings of social rejection. These data show that greater amygdala activity in response to a stressor, as well as tighter coupling between the amygdala and the DMPFC, are associated with greater increases in inflammatory activity. Results from this study begin to identify neural mechanisms that might link stress with increased risk for inflammation-related disorders such as cardiovascular disease and depression.
Inflammatory processes are implicated in a number of diseases for which there are known socioeconomic status (SES) disparities, including heart disease and diabetes. Growing evidence also suggests SES gradients in levels of peripheral blood markers of inflammation. However, we know little about potential gender and racial/ethnic differences in associations between SES and inflammation, despite the fact that the burden of inflammation-related diseases varies by gender and race. The present study examines SES (education and income) gradients in levels of two inflammatory biomarkers, C-reactive protein (CRP) and interleukin-6 (IL-6), in a biethnic (White and Black) sample of men and women (n = 3,549, aged 37–55 years) in the USA from the CARDIA Study. Health status, behavioral and psychosocial variables that may underlie SES differences in inflammatory biomarker levels were also examined. Age-adjusted CRP and IL-6 levels were inversely associated with education level in each race/gender group except Black males. Income gradients were also observed in each race/gender group for IL-6 and in White females and males for CRP. In general, differences in CRP and IL-6 levels between low and high SES groups were reduced in magnitude and significance with the addition of health status, behavioral, and psychosocial variables, although the impact of the addition of model covariates varied across race/gender groups and different SES-inflammation models. Overall, findings indicate SES gradients in levels of inflammation burden in middle-aged White and Black males and females.
IntroductionDepression can suppress immune function, leading to lower resistance against infection and longer healing times in depressed individuals. Sexuality may also influence immune function, with evidence that sexual activity is associated with lowered immune function in women and mixed results in men. Immune mediators like immunoglobulin A (IgA) are immediately relevant to sexual health, since they are the first line of defense against pathogens at mucous membranes like the vagina. AimThis study aims to determine if and how depression, sexual activity, and their interaction impact salivary IgA (SIgA) in men and women. Methods
In Study 1, a community-based sample of 84 women and 88 men provided saliva samples and completed questionnaires on their demographic background, level of depression, and frequency of partnered and solitary sexual activity. Study 2, conducted separately in an undergraduate student sample of 54 women and 52 men, had similar methods. Main Outcome MeasuresThe main outcome measures were scores on the General Well-Being Schedule depression subscale, reported frequency of sexual activity, and SIgA levels as measured by enzyme immunoassay. ResultsAcross studies, higher levels of partnered sexual activity were associated with lower SIgA for women with high depression scores, but not for women with low depression scores. In contrast, higher levels of partnered sexual activity were associated with higherSIgA for men with high depression scores, but not for men with low depression scores. Conclusion
Our results show that partnered sexual activity is a risk factor for lowered immunity in women with depressive symptoms but a possible resilience factor for men with depressive symptoms. This suggests a role for sexual activity in determining the impact of depression on physical health parameters. Lorenz T and van Anders S. Interactions of sexual activity, gender, and depression with immunity. J Sex Med 2014;11:966-979.
Sleep duration and quality are associated with adverse physical health outcomes. The mechanisms are not well understood, and little is known about associations with biomarkers in older population cohorts. This study assessed cross-sectional associations between self-reported sleep measures and biomarkers in a representative sample of British people aged 50 years and above. Participants were 6465 men and women aged 50-99 years from the English Longitudinal Study of Ageing (ELSA). Associations of sleep duration and sleep disturbance with C-reactive protein (CRP), fibrinogen, dehydroepiandrosterone sulfate (DHEAS) and hemoglobin were analyzed, adjusting for age, wealth, body mass index (BMI), smoking, physical activity, limiting long-standing illness and depressive symptoms. In men, long sleep duration (OR: 1.50, 1.05-2.14) and greater sleep disturbance (OR: 1.29, C.I. 1.05-1.59) were associated with raised CRP levels, while long sleep was also related to raised plasma fibrinogen (P=0.001). DHEAS levels were lower among men reporting more sleep disturbances (P=0.016), but were not related to sleep duration. Sleep duration (P=0.015) and sleep disturbance (P=0.039) were associated with lower hemoglobin levels, and anemia was more prevalent among men with disturbed sleep (OR: 1.73, C.I. 1.13-2.65). In women more disturbed sleep was associated with greater likelihood of anemia (OR: 1.59, C.I. 1.02-2.46), but there was no relationship between sleep disturbance or duration with other biomarkers. This study suggests that self-reported sleep duration and disturbance are related to biological risk factors in community-dwelling older adults, with different associations being present in men and women. A better understanding of these relationships using longitudinal cohort studies will broaden our understanding of the mechanisms relating sleep indices and ill health in advancing age.