Associations between psychosocial factors and circulating cytokines in breast cancer survivors.

OBJECTIVE: Research has established links between social isolation and heightened levels of proinflammatory cytokines (e.g., interleukin-6 [IL-6], tumour necrosis factor alpha [TNF-α]). Recent advances allow for the examination of cytokines that may also play a role in antiviral immunity (interferon-gamma [IFN-γ]). The present work explored how various features of social experience relate to circulating cytokines in breast cancer survivors, as inflammation has been tied to cancer recurrence and mortality. DESIGN: Female breast cancer survivors (N = 43) completed a blood draw to assess circulating levels of proinflammatory cytokines (IL-6, TNF-α) and levels of a cytokine that also relates to antiviral immunity (IFN-γ). MAIN OUTCOME MEASURES: We examined associations between cytokines and different aspects of social experience, including household size, psychosocial well-being, and social threat anxiety. RESULTS: Circulating levels of IFN-γ were associated with larger household size (r = 0.32, p = 0.04) and higher levels of psychosocial well-being (r = 0.33, p = 0.04). Additionally, heightened levels of IL-6 were associated with social threat anxiety (r = 0.38, p = 0.01). Heightened IL-6 was also associated with household size (r = 0.33, p = 0.03). CONCLUSION: These findings are consistent with work suggesting that antiviral immunity and inflammation may have distinct contributions to the links between social experience and health, particularly for those previously diagnosed with breast cancer.

Ventromedial prefrontal cortex activity differentiates sick from healthy faces: Associations with inflammatory responses and disease avoidance motivation.

BACKGROUND: Humans are able to discern the health status of others using olfactory and visual cues, and subsequently shift behavior to make infection less likely. However, little is known about how this process occurs. The present study examined the neural regions involved in differentiating healthy from sick individuals using visual cues. METHODS: While undergoing a functional magnetic resonance imaging scan, participants (N = 42) viewed facial photos of 30 individuals (targets) who had been injected with an inflammatory challenge--low-dose endotoxin (i.e., sick) or placebo (i.e., healthy), and rated how much they liked each face. We examined regions implicated in processing either threat (amygdala, anterior insula) or cues that signal safety (ventromedial prefrontal cortex [VMPFC]), and how this activity related to their liking of targets and cytokine levels (interleukin-6, tumor necrosis factor-α) exhibited by the targets. RESULTS: Photos of sick faces were rated as less likeable compared to healthy faces, and the least liked faces were those individuals with the greatest inflammatory response. While threat-related regions were not significantly active in response to viewing sick faces, the VMPFC was more active in response to viewing healthy (vs. sick) faces. Follow-up analyses revealed that participants tended to have lower VMPFC activity when viewing the least liked faces and the faces of those with the greatest inflammatory response. CONCLUSIONS: This work builds on prior work implicating the VMPFC in signaling the presence of safe, non-threatening visual stimuli, and suggests the VMPFC may be sensitive to cues signaling relative safety in the context of pathogen threats.

Writing content predicts benefit from written expressive disclosure: Evidence for repeated exposure and self-affirmation.

Expressive disclosure regarding a stressful event improves psychological and physical health, yet predictors of these effects are not well established. The current study assessed exposure, narrative structure, affect word use, self-affirmation and discovery of meaning as predictors of anxiety, depressive and physical symptoms following expressive writing. Participants (N = 50) wrote on four occasions about a stressful event and completed self-report measures before writing and three months later. Essays were coded for stressor exposure (level of detail and whether participants remained on topic), narrative structure, self-affirmation and discovery of meaning. Linguistic Inquiry and Word Count software was used to quantify positive and negative affect word use. Controlling for baseline anxiety, more self-affirmation and detail about the event predicted lower anxiety symptoms, and more negative affect words (very high use) and more discovery of meaning predicted higher anxiety symptoms three months after writing. Findings highlight the importance of self-affirmation and exposure as predictors of benefit from expressive writing.

The neural sociometer: brain mechanisms underlying state self-esteem.

On the basis of the importance of social connection for survival, humans may have evolved a "sociometer"-a mechanism that translates perceptions of rejection or acceptance into state self-esteem. Here, we explored the neural underpinnings of the sociometer by examining whether neural regions responsive to rejection or acceptance were associated with state self-esteem. Participants underwent fMRI while viewing feedback words ("interesting," "boring") ostensibly chosen by another individual (confederate) to describe the participant's previously recorded interview. Participants rated their state self-esteem in response to each feedback word. Results demonstrated that greater activity in rejection-related neural regions (dorsal ACC, anterior insula) and mentalizing regions was associated with lower-state self-esteem. Additionally, participants whose self-esteem decreased from prescan to postscan versus those whose self-esteem did not showed greater medial prefrontal cortical activity, previously associated with self-referential processing, in response to negative feedback. Together, the results inform our understanding of the origin and nature of our feelings about ourselves.