Abstract
Socioeconomic hardship (SES-H) is a known risk factor for adolescent suicidal thoughts and behaviors (STB). This study examined sleep health as a pathway linking SES-H to suicide risk and evaluated the moderating role of Default Mode Network (DMN) coherence. Data came from three waves of the Adolescent Brain Cognitive Development (ABCD) Study (N = 11,878). Increased SES-H predicted greater suicidal ideation and attempts. Shorter sleep duration mediated the association with ideation, while high DMN coherence attenuated the indirect effect of SES-H on ideation via sleep. Findings highlight sleep health as a mechanism connecting socioeconomic adversity to suicidality and suggest DMN coherence may function as a neuroprotective factor for youth resilience.