There is substantial evidence that personality traits, such as self-criticism and dependency, predict the development of depression and anxiety symptoms, as well as depressive episodes. However, it is unknown whether self-criticism and dependency predict the first onset of depressive and anxiety disorders, and unclear how to characterize dynamic mechanisms by which these traits, stressful life events, and psychopathology influence one another over time. In this study, 550 female adolescents were assessed at baseline, 528 and 513 of whom were assessed again at Waves 2 and 3, respectively, over the course of 18 months. Self-criticism and dependency were assessed with self-report inventories, depressive and anxiety disorders were assessed with diagnostic interviews, and stressful life events were assessed via semistructured interview. Logistic regression analyses showed that self-criticism and dependency significantly predicted the first onset of nearly all depressive and anxiety disorders (significant polychoric rs ranged from .15–.42). Subsequent path analyses focused on prediction of depression, and supported several conceptual models of personality-stress-psychopathology relationships. In particular, Personality × Stress interactions were evident for both dependency and self-criticism. These interactions took the form of dual vulnerability, such that stressful life events predicted an increased probability of a later depressive disorder only at low levels of each trait. Results suggest the traits of self-criticism and dependency are important to consider in understanding who is at risk for depressive and anxiety disorders.