The current study examined several theories of depression in a sample of middle adolescents. At Time 1, 367 ninth graders completed measures assessing depressogenic inferential styles, the tendency to ruminate in response to depressed mood, and depressive symptoms. Six weeks later, participants completed measures assessing negative events and depressive symptoms. In line with the hopelessness theory, a depressogenic weakest link interacted with negative events to predict increases in hopelessness depression symptoms but not in more general depressive symptoms. Further, providing partial support for the response styles theory, the tendency to ruminate in response to depressed mood predicted increases in hopelessness depression symptoms but not in more general depressive symptoms. Contrary to the integrative theory, the relationship between a depressogenic weakest link and increases in hopelessness depression symptoms following negative events was not moderated by a ruminative response style. (Contains 2 tables and 1 figure.)