Pro-inflammatory cytokines IL-1α, IL-6 and TNF-α in major depressive disorder: Sex-specific associations with psychological symptoms

Abstract

The pro-inflammatory cytokines IL-1α, IL-6 and TNF-α are associated with major depressive disorder, psychological distress, cardiovascular health, and obesity. However, there is limited research that has examined multiple associations between these variables, among individuals with major depressive disorder in comparison to a control cohort, including sex differences. In this study, data was analysed from 60 individuals with major depressive disorder and 60 controls, including plasma IL-1α, IL-6 and TNF-α, adiposity measures (body mass index; waist circumference), cardiovascular health indices (blood pressure; heart rate) and psychological symptoms (depressive severity; anxiety; hostility; stress). The cytokines were compared by group and sex, and correlated with measures of adiposity, cardiovascular health indices and psychological health. Plasma IL-1α and IL-6 were higher in major depressive disorder group versus control, but with a sex interaction for IL-6, with this group difference only among females. TNF-α did not differ between groups. IL-1α and IL-6 correlated with depressive severity, anxiety, hostility, and stress, while TNF-α correlated only with anxiety and hostility. Psychopathology was associated with IL-1α in males only, and with IL-6 and TNF-α in females only. None of the cytokines correlated with body mass index, waist circumference, blood pressure or heart rate. The result of group by sex interaction for IL-6, and sex specific associations between pro-inflammatory cytokines and psychometrics could be aetiologically important in depression interventions and treatments for females versus males, warranting further investigation.

Differential Learned Helplessness Phenotypes in Male and Female Rats: Exploring the Therapeutic Impact of Cannabidiol Treatment

“…It is essential to recognize that male and female brains can respond in different manners to the same experimental manipulations. Notably, there are indications of male-female differences in endocannabinoid, serotonergic, in ammatory, and estrogenic markers and activity, all of which may in uence depressive symptoms [86][87][88][89][90][91][92][93][94][95][96][97][98][99]. The observed sex differences in stress response likely stem from a complex interplay of factors, including variations in serotonergic function, uctuations in the estrous cycle, and activity within the hypothalamic-pituitary-adrenal (HPA) axis.…”