<p>The prevalence of depression has sharply increased among adolescents and young adults over the past decade. Depression in adolescence and young adulthood has raised growing concern because it is associated with an increased risk of suicide, thus heightening the likelihood of future suicidal behavior and completed suicide. However, the neurobiological underpinnings of suicidal behavior in depressed adolescents and young adults remain poorly understood. In this study, we investigated the dynamic functional connectivity (dFC) between brain regions in reward network and identified alterations in the dynamics of functional connectivity patterns within this network in adolescents and young adults with depression, both with and without a history of suicide attempts, using dFC analysis. Our findings revealed significant differences in dynamic functional connectivity between several key brain regions, including the left ventral striatum and putamen, the left anterior insula and the left medial superior frontal gyrus, the right anterior insula and the right anterior central and left medial superior frontal gyrus, as well as the anterior auxiliary motor area and the inferior frontal gyrus, among the sMDDgroup, nMDD group and HC group. These results demonstrate that the temporal dynamic changes in functional connectivity of reward network were associated with suicidality, suggesting that such changes may serve as an important biomarker for adolescent suicidality.</p>