Effectiveness of Stress-Reducing Interventions on the Response to Challenges to the Immune System: A Meta-Analytic Review

Abstract

<b><i>Background:</i></b> There is consistent evidence showing an interplay between psychological processes and immune function in health and disease processes. <b><i>Objectives:</i></b> The present systematic review and meta-analysis aims to provide a concise overview of the effectiveness of stress-reducing psychological interventions on the activation of immune responses in both healthy subjects and patients. <b><i>Methods:</i></b> Included are 3 types of challenges: in vivo, in vitro, and psychophysiological. Such challenges are designed to mimic naturally occurring immune-related threats. <b><i>Results:</i></b> A systematic literature search was conducted using PubMed, EMBASE, and PsychInfo, resulting in 75 eligible studies. The risk of bias was assessed with the Cochrane risk-of-bias tool. Across all studies, a small-to-medium effect size was found for the effects of psychological interventions on optimization of the immune function (<i>g</i> = 0.33; 95% CI 0.22–0.43). While the largest effects were found for in vivo immune-related challenges (<i>g</i> = 0.61; 95% CI 0.34–0.88; especially on studies that incorporated skin tests and wound healing), studies incorporating psychophysiological challenges and in vitro immune-related stimulations similarly suggest more optimal immune responses among those receiving stress-reducing interventions (<i>g</i> = 0.28; 95% CI 0.15–0.42). <b><i>Conclusion:</i></b> These findings showed substantial heterogeneity depending on the type of challenge, the study populations, and the intervention types. These data demonstrate support for the effectiveness of stress-reducing psychological interventions in improving immunity in studies that tested immune function by means of incorporating an in vivo<i>,</i>in vitro, or psychophysiological challenge. Future research should more consistently incorporate challenges into the study design to gather more insights in the mechanisms underlying the optimized immune function following a psychological intervention. This is also relevant for clinical practice, as psychological interventions can possibly supplement, or at least partially replace, current drug treatments in various somatic conditions to reduce side effects.

Multimodal Psychotherapeutic Inpatient Therapy of Depression Is Successful in Patients With High Cytokine Production

“…Though compared to flow cytometry for the identification of PBMC subpopulations, the determination of cytokines in cell culture supernatants can be done with comparably smaller effort. Future studies in this vein could establish this more complex but highly instructive analysis side by side with more easily applicable protocols to determine hyper-reactivity of the immune system to challenge in the clinic, for example by using skin tests ( 70 ).…”

An Internet-Based Psychological Intervention With a Serious Game to Improve Vitality, Psychological and Physical Condition, and Immune Function in Healthy Male Adults: Randomized Controlled Trial

“…Psychological interventions have been shown to be effective in improving self-reported health outcomes [ 1 , 2 ] and immune status [ 3 - 5 ]. Two meta-analytic reviews found modest support for improved immune function after psychological interventions [ 6 , 7 ]. However, it is difficult to draw conclusive findings from these studies due to the large heterogeneity in the incorporated interventions (ie, various types of relaxation, conditioning, disclosure, and stress management interventions) and immunological outcomes (ie, quantitative and qualitative).…”

“…However, it is difficult to draw conclusive findings from these studies due to the large heterogeneity in the incorporated interventions (ie, various types of relaxation, conditioning, disclosure, and stress management interventions) and immunological outcomes (ie, quantitative and qualitative). Moreover, novel developments in psychological treatments may potentially further enhance the effectiveness of psychological interventions in improving self-reported and immunological health outcomes [ 7 ]. A rather novel development focuses on providing psychological interventions based on cognitive behavioral therapy (CBT) via the internet (ICBT).…”

“…Most research has focused on basal health outcomes; however, health outcomes assessed in situations that challenge actual health status might better represent reactions to real-time stressors [ 17 ]. Few studies have incorporated immunological or psychophysiological challenges in their study design.…”

“…Psychophysiological challenges can provide insights into participants’ responses to stress after a psychological intervention (eg, exposure to a social evaluative stressor). The studies that incorporated challenges into their design often focused on incorporating one specific challenge and did not combine and compare effects on both in vitro and in vivo immunological as well as psychophysiological challenges [ 17 ]. For example, a recent systematic review of studies that specifically examined wound healing after a psychological intervention provided some support for the optimization of immunological markers after this challenge [ 22 ].…”