Effects of psychological interventions on systemic levels of inflammatory biomarkers in humans: A systematic review and meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 29630988 · doi:10.1016/j.bbi.2018.04.005
What was done
A systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated the effects of psychological interventions on inflammatory biomarkers in adults. Two researchers independently searched electronic databases, selected eligible studies, extracted data, and assessed methodological quality. The analysis included 19 RCTs with a total of 1,510 participants.
What was found
Psychological interventions produced a statistically significant, small pre-to-post reduction in pro-inflammatory biomarker levels (g = 0.15, p = .008, 95% CI [0.04, 0.26]). This effect was not maintained during follow-up (g < -0.01, p = .964, 95% CI [-0.19, 0.18]). Among individual biomarkers, only C-reactive protein (CRP) significantly decreased. Moderation analyses were non-significant overall, but studies preselecting participants for elevated psychological distress showed a larger significant within-group effect (g = 0.29, p = .047).
Why it matters
This review demonstrates that psychological interventions can acutely lower systemic inflammatory markers such as CRP, especially in distressed individuals, although the reduction dissipates once treatment ends.
Limits
The observed effect size was small and transient, and significant reductions were restricted to CRP rather than across all pro-inflammatory markers. Most included trials did not screen for baseline systemic inflammation, and subgroup moderation analyses lacked statistical significance.
Cited by
- supports Psychological stress causes physical inflammation in the body.