A systematic review and meta-analysis of the effect of emotion regulation on cortisol

It is generally acknowledged that hormones are implicated in socioemotional behavior, yet little is known about the role of hormones in the context of emotion regulation. The aims of the present review and meta-analysis were to review and synthesize the available evidence pertaining to the effect of emotion regulation instructions on hormones, and to investigate whether this effect varies according to: type of hormone, context (e.g., emotion induction procedure), emotion regulation characteristics (e.g., emotion regulation strategy), and presence and type of psychiatric disorder. PubMed, PsycINFO, and CINAHL were searched for experimental studies assessing the effect of instructed emotion regulation on levels of hormones (i.e., testosterone, cortisol, oxytocin, estradiol, and vasopressin) in physically healthy adults. The literature search yielded 17 relevant studies, 16 investigating cortisol and one investigating testosterone. Of these, 12 cortisol studies had eligible data for the meta-analysis. The results of the meta-analysis indicated no statistically significant effect of receiving an emotion regulation instruction compared with receiving no instruction on the cortisol response to subsequent emotion induction (g = -0.05, p = .48). However, within-person comparisons of change from an unregulated response to a regulated response indicated a significant change in cortisol levels (g = 0.18, p = .03) consistent with the specified regulation goal (i.e., either up-or downregulation). No statistically significant effects were found in subgroup meta analyses conducted according to context, emotion regulation characteristics or psychiatric disorders. Taken together, the findings indicate that emotion-induction procedures are associated with increases in cortisol that may subsequently return to equilibrium regardless of emotion-regulation instructions. Based on the large gaps in research (e.g., few studies investigated other hormones than cortisol, few studies included self-report measures of emotions) identified in the present review, we conclude that the effect of emotion regulation on hormones remains poorly understood. Prospero registration: CRD42020157336.