The aim of the authors' study was to explore a model of suicidal ideation among adolescents in which environmental risk factors were mediated by both depression and defensive psychopathology. Suicidal ideation, depression, defensive psychopathology (substance use, borderline traits or symptoms, dissociative symptoms), parental attachment, and stressful life events were assessed among 615 adolescents (62% male). Despite gender differences, the proposed model received support. Findings suggest a psychodynamic relationship linking suicidal ideation to defensive mechanisms, aiming to alleviate depressive affects.