Exploring neural mechanisms of the health benefits of gratitude in women: A randomized controlled trial.

BACKGROUND: Gratitude has received growing interest as an emotion that can bring greater happiness and health. However, little is known about the effects of gratitude on objective measures of physical health or the neural mechanisms that underlie these effects. Given strong links between gratitude and giving behavior, and giving and health, it is possible that gratitude may benefit health through the same mechanisms as giving to others. Thus, this study investigated whether gratitude activates a neural 'caregiving system' (e.g., ventral striatum (VS), septal area (SA)), which can downregulate threat responding (e.g., amygdala) and possibly cellular inflammatory responses linked to health. METHODS: A parallel group randomized controlled trial examined the effect of a six-week online gratitude (n = 31) vs. control (n = 30) writing intervention on neural activity and inflammatory outcomes. Pre- and post-intervention, healthy female participants (ages 35-50) reported on support-giving behavior and provided blood samples to assess circulating plasma levels and stimulated monocytic production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)). Post-intervention, participants completed a gratitude task and a threat reactivity task in an fMRI scanner. RESULTS: There were no significant group differences (gratitude vs. control intervention) in neural responses (VS, SA, or amygdala) to the gratitude or threat tasks. However, across the entire sample, those who showed larger pre- to- post-intervention increases in self-reported support-giving showed larger reductions in amygdala reactivity following the gratitude task (vs. control task). Additionally, those who showed larger reductions in amygdala reactivity following the gratitude task showed larger pre-to-post reductions in the stimulated production of TNF-α and IL-6. Importantly, gratitude-related reductions in amygdala reactivity statistically mediated the relationship between increases in support-giving and decreases in stimulated TNF-α production. CONCLUSION: The observed relationships suggest that gratitude may benefit health (reducing inflammatory responses) through the threat-reducing effects of support-giving.

Associations between amygdala reactivity to social threat, perceived stress and C-reactive protein in breast cancer survivors.

Chronic inflammation in women diagnosed with breast cancer is critically linked with tumor progression, metastasis and survival. C-reactive protein (CRP)-a circulating marker of inflammation-is an important prognostic marker for cancer-related outcomes in breast cancer survivors (e.g. recurrence, fatigue). Psychological stress, which increases circulating markers of inflammation following sympathetic nervous system (SNS) activation, may modulate tumor-relevant inflammatory processes. However, little is known about neural mechanisms that might link stress and downstream SNS-initiated proinflammatory processes, such as elevated CRP. Past work suggests that threat-related neural regions, such as the amygdala, may be key in translating psychological stress into SNS activity and subsequent peripheral inflammation. Thus, we examined amygdala reactivity to socially threatening stimuli in association with perceived stress and plasma CRP levels to further elucidate neuro-immune pathways of social threat processing within breast cancer survivors (N = 37). Significant positive correlations were found between left amygdala reactivity in response to socially threatening stimuli (e.g. angry/fearful faces vs happy faces) and perceived stress in the previous month (r = 0.32, P = 0.025) and between left amygdala reactivity and CRP (r = 0.33, P = 0.025). This work builds on prior research implicating the amygdala as a key structure in crosstalk between threat-related neural circuitries and peripheral inflammation, particularly within cancer survivors.

Exploring the role of gratitude and support-giving on inflammatory outcomes.

Although there has been much interest in understanding the effect of gratitude on health-related outcomes, this remains an understudied area of research, particularly regarding mechanisms and measurement of biological outcomes. The present study explored whether a gratitude intervention could reduce inflammatory outcomes and whether this occurred through increased support-giving. Healthy women (n = 76) were randomly assigned to a 6-week gratitude intervention (i.e., writing on topics intended to induce gratitude) or a control condition (i.e., neutral writing). Support-giving and markers of inflammation were measured pre- and postintervention. Those in the gratitude intervention (vs. control) reported higher postintervention levels of support-giving. Moreover, those with lower levels of psychological distress gave more support as a function of the gratitude intervention. Regarding inflammatory outcomes, although there was no effect of the gratitude intervention on postintervention inflammatory markers, increases in support-giving across the entire sample were related to decreases in inflammatory markers. These results, along with a scarcity of work in this area, suggest that further work is needed to more fully understand the relationships between gratitude and biological markers relevant to health. Finally, these novel findings linking support-giving and decreases in inflammation also indicate that the mammalian caregiving system, associated with enhanced support-giving and reduced physiological stress responding, is a mechanism worth further examination to elucidate the links between social support and health. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Randomized controlled trial of expressive writing for psychological and physical health: the moderating role of emotional expressivity.

The current study assessed main effects and moderators (including emotional expressiveness, emotional processing, and ambivalence over emotional expression) of the effects of expressive writing in a sample of healthy adults. Young adult participants (N=116) were randomly assigned to write for 20 minutes on four occasions about deepest thoughts and feelings regarding their most stressful/traumatic event in the past five years (expressive writing) or about a control topic (control). Dependent variables were indicators of anxiety, depression, and physical symptoms. No significant effects of writing condition were evident on anxiety, depressive symptoms, or physical symptoms. Emotional expressiveness emerged as a significant moderator of anxiety outcomes, however. Within the expressive writing group, participants high in expressiveness evidenced a significant reduction in anxiety at three-month follow-up, and participants low in expressiveness showed a significant increase in anxiety. Expressiveness did not predict change in anxiety in the control group. These findings on anxiety are consistent with the matching hypothesis, which suggests that matching a person's naturally elected coping approach with an assigned intervention is beneficial. These findings also suggest that expressive writing about a stressful event may be contraindicated for individuals who do not typically express emotions.