Inflammation and depression treatment response to electroconvulsive therapy: Sex-specific role of interleukin-8

• Published in: Brain, behavior, and immunity behavior, and immunity, 2020-10, Vol.89, p.59-66
• Main Authors: Kruse, Jennifer L., Olmstead, Richard, Hellemann, Gerhard, Wade, Benjamin, Jiang, Janina, Vasavada, Megha M., Brooks III, John O., Congdon, Eliza, Espinoza, Randall, Narr, Katherine L., Irwin, Michael R.
• Format: Article
• Language: English
• Subjects: Biomarker; Depression; Depressive Disorder, Major; Electroconvulsive Therapy; Female; Humans; Inflammation; Interleukin-8; Major depressive disorder; Male; Psychiatric Status Rating Scales; Sex differences; Treatment Outcome
• ISSN: 0889-1591; 1090-2139
• DOI: 10.1016/j.bbi.2020.05.069

•Lower baseline IL-8 was associated with ECT response among females, but not males.•Increasing IL-8 was associated with decreasing depression severity in females only.•Other inflammatory marker levels did not differ based on responder status and sex. Females suffer from depression at twice the rate of males and have differential neural and emotional responses to inflammation. However, sex-specific evaluation of relationships between inflammation and response to depression treatments are lacking. Some data suggest that interleukin(IL)-8 predicts treatment response to antidepressants and has a relationship with depressive symptom severity. This study examines whether IL-8 predicts treatment response to electroconvulsive therapy (ECT), and whether there are sex specific effects. In 40 depressed patients (22 female), plasma levels of IL-8, as well as other markers of inflammation including IL-6, IL-10, tumor necrosis factor (TNF)-α, and C-reactive protein (CRP) were obtained prior to administration of ECT and after completion of the index treatment series. Depression treatment response was defined as ≥ 50% reduction in Hamilton Depression Rating Scale (HAM-D) Score. Baseline levels of IL-8 differed by responder status, depending on sex (group × sex interaction: β = -0.571, p = 0.04), with female responders having lower levels of IL-8 at baseline as compared to female non-responders [t(20) = 2.37, p = 0.03]. Further, IL-8 levels from baseline to end of treatment differed by responder status, depending on sex (group × sex × time interaction: [F(1,36) = 9.48, p = 0.004]), and change in IL-8 from baseline to end of treatment was negatively correlated with percentage change in HAM-D score in females (β = -0.458, p = 0.03), but not in males (β = 0.315, p = 0.20). Other inflammatory markers did not differ in relation to responder status and sex. Further evaluation of sex differences in the relationship between IL-8, depression, and treatment response, across disparate treatment modalities, may inform mechanisms of response and aid in development of personalized medicine strategies.