This prospective study tested the diathesis-stress and causal mediation components of the integration of the hopelessness and self-esteem theories of depression. One hundred and thirty-six high school seniors applying early decision to the University of Pennsylvania completed measures of depressed mood, hopelessness, self-esteem, and depressogenic inferential styles 1-8 weeks before receiving their admissions decision (Time 1). The assessment of self-esteem and depressogenic inferential styles was preceded by a priming task designed to activate latent cognitive vulnerability factors. In addition, participants completed measures of mood and hopelessness shortly after they received their admissions decision (Time 2) and 4 days later (Time 3). In line with the diathesis-stress component of the theory, depressogenic inferential styles about consequences, causes, and the self for achievement events interacted with low self-esteem to predict enduring depressive mood reactions (Time 3) in negative outcome students. In addition, in partial support of the causal mediation component of the theory, in negative outcome students with low self-esteem, the relationship between depressogenic inferential styles and enduring depressive mood reactions was partially mediated by hopelessness.