Associations between the Dietary Inflammatory Index and depression among pregnant and postpartum women: analysis of NHANES 2005–2018

In this cross-sectional study of pregnant and postpartum women in the U. S., a higher Dietary Inflammatory Index was associated with a greater risk of depression, but this relationship was markedly non-linear. Diets with very high proinflammatory potential were linked to significantly increased odds of perinatal depression, whereas more anti-inflammatory diets did not result in a further decrease in depression risk below that threshold. However, owing to the inherent limitations of the study design, causality cannot be established, and a reverse effect of depressive symptoms on dietary choice cannot be ruled out.