BACKGROUND: Many studies have indicated that adverse cardiovascular health (CVH) behaviors are associated with an elevated risk of depression. However, the dose-response relationship between the two and the relative contributions of individual CVH components to depression risk remain unclear. METHODS: We utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2015 and 2018. Quantified CVH was assessed using the Life's Simple 8 (LE8) instrument, depression symptoms were measured through the Patient Health Questionnaire-9 (PHQ-9), and a weighted logistic regression, restrictive cubic splines (RCS), subgroup analyses on sociodemographic factors, weighted quantile sum (WQS) regression were employed to evaluate the association between CVH and depression. RESULTS: In a fully adjusted logistic regression model, for each unit increase in LE8 score, there was a corresponding decrease of 0.07 in depression score (β=-0.07, 95%CI -0.07 to -0.06, p < 0.001). The RCS model indicated a significant non-linear relationship between CVH and depression. Subgroup analyses revealed that the association between CVH and depression was strongest among women, ethnic minorities, individuals with low education levels, and those living in poverty. WQS regression analysis indicated that tobacco exposure and sleep health accounted for more than 60% of the cumulative effects of CVH indicators on depression. CONCLUSION: This study indicates a significant negative correlation between overall cardiovascular health measured by LE8 scores and depression. Prioritizing interventions targeting lifestyle modifications to alleviate the burden of depression in public health initiatives is crucial.