The association between adversity and hair cortisol levels in humans: A meta-analysis. (May 2019)

• Record Type: Journal Article
• Authors: Khoury, Jennifer E.; Bosquet Enlow, Michelle; Plamondon, André; Lyons-Ruth, Karlen
• Is Part Of: Psychoneuroendocrinology. Volume 103(2019)
• Page Start: 104
• Page End: 117
• Publication Date: 2019-05
• Subjects: Hair cortisol -- Chronic stress -- Adversity -- Adverse experiences -- Trauma -- Meta-analysis; Psychoneuroendocrinology -- Periodicals; Endocrinology -- Periodicals; Neurology -- Periodicals; Psychiatry -- Periodicals; Neuropsychoendocrinologie -- Périodiques; 616.8
• DOI: 10.1016/j.psyneuen.2019.01.009
• Languages: English
• ISSNs: 0306-4530

Abstract

Highlights: This meta-analysis shows that adversity is associated with both elevated and dampened hair cortisol levels. There is significant heterogeneity in the effect of adversity on hair cortisol. The association between adversity and hair cortisol is moderated by features of adversity, hair cortisol, and sample characteristics. Abstract: Adverse life events are associated with a constellation of negative health outcomes. Theory and research suggest that the hypothalamic-pituitary-adrenal (HPA) axis acts as one mechanism connecting adverse experiences with negative health outcomes. However, this relation is complicated by the potential for adversity to be associated with both hyperactivity and hypoactivity of the HPA axis, as assessed in both animal and human studies. Over the past decade, methodological advances have enabled the sampling of cortisol stored in hair, which provides a marker of HPA axis activity over a several-month period. The present meta-analysis included 28 studies to assess the strength and direction of the relation between adverse experiences and hair cortisol levels. Analyses were conducted using multilevel modeling (MLM) to quantify the magnitude of effects and mixture modeling to identify distinct subgroups of studies. Results of MLM analyses indicated that the overall effect size was small but significant d = 0.213, 95% CI [0.034, 0.397]. There was also significant between-study variance (τ = 0.155, 95% CI [0.065, 0.367]). Mixture modeling to identify distinct classes of studies based on effect size and direction resulted in a 2-class model: The first class included four studies with an overall negative and moderate effect size ( d = -0.478, 95% CI [-0.639, -0.318]), and the second class included the remaining 24 studies with an overall positive and significant, albeit small, effect size ( d = 0.141, 95% CI [0.084, 0.199]). Moderator analyses indicated that the strength and direction of the association between adversity and hair cortisol were moderated by features of the adversity exposure (e.g., type of adversity, timing of adversity), characteristics of the samples (e.g., clinical status, racial distribution), and features of the publication (e.g., publication type, geographic region of study). The findings refine our understanding of the long-term impact of adversity on dysregulation of the HPA axis, particularly as reflected in hair cortisol measures.