<p>Depression rates among young adults (aged 18–25) continue to rise, and suicide remains one of the leading causes of death in this population. The aim of this study was to examine risk factors impacting depression severity, suicidal behavior (SB), and non-suicidal self-injury (NSSI) in young adults with depression, focusing on childhood trauma, impulsivity, and resilience. Young adults with a clinical diagnosis of depression were included in this observational study. Clinical assessments included validated measures of depression severity, SB, NSSI, childhood trauma, impulsivity, and resilience. Spearman’s correlation showed that demographic factors, childhood trauma, and impulsivity were significantly associated with depression severity, SB, and NSSI. However, multiple regression analyses showed that resilience was a significant protective factor for depression severity (<i>p</i> = .042), while other factors did not reach significance. In contrast, total childhood trauma score was a significant risk factor for SB (<i>p</i> &lt; .001) and NSSI (<i>p</i> = .008). A positive family history of mental disorders was also a significant risk factor for SB (<i>p</i> = .009). These findings may contribute to the development of therapeutic interventions aimed at modifying these risk factors and protective factors. Such an approach may contribute to decreasing depression severity and the risk of SB and NSSI in young adults with depression.</p>