CXCL8 and major depressive disorder: PROMIS-Sleep was moderately associated with IL-8 (<i>r<sub>s</sub></i> = 0.39; 95% CI 0.06, 0.64; <i>p</i> = 0.021).<h4>Conclusions</h4>While preliminary, our findings suggest that associations between inflammatory biomarkers and depression may not be consistent across all depressive measures or symptom dimensions.