Kim SW, et al. - The associations between interleukin (IL)-6 and IL-18 and depression in patients with acute coronary syndrome (ACS) and potential interactions between statin use and pro-inflammatory cytokines on depression in this population were examined. Following ACS, levels of pro-inflammatory cytokines seemed to predict the development of depression. Statins attenuated the effects of cytokines on depression.

• Pooled datasets were used from 1-year follow-up data from a 24-week randomized double-blind placebo-controlled trial (RCT) of escitalopram for treatment of depressive disorder and data from a naturalistic, prospective, observational cohort study in patients with ACS.
• The authors measured IL-6 and IL-18 levels at baseline.
• They used logistic regression models to examine independent associations of IL-6/IL-18 levels with the depressive disorder at baseline and at 1 year.
• To determine whether any significant association emerged, they repeated all analyses by reference to statin use.

• A total of 378 participants (39.0%) had major or minor depression at baseline, among the 969 participants.
• The authors observed depression in 183 patients (25.7%), among the 711 patients followed-up at 1 year.
• They demonstrated that higher IL-6 and IL-18 levels at baseline were significantly associated with baseline depression after adjusting for other variables (adjusted p-values = 0.005 and 0.001, respectively) in logistic regression analysis.
• Furthermore, after adjusting for other variables, IL-6 and IL-18 levels were significantly higher in patients with depression at the 1-year follow-up amongst those not taking statins (adjusted p-values = 0.040 and 0.004, respectively); but this was not the case in patients taking statins.