Objectives. This prospective study tested the integration of the diathesis-stress component of the hopelessness theory of depression (Abramson, Metalsky, & Alloy, 1989) and Persons and Miranda's (1992) activation hypothesis (i.e. depressogenic inferential styles are typically latent cognitive processes that must be primed in order to be accurately assessed). Design. In order to test the diathesis-stress component of the hopelessness theory, we used a short-term longitudinal design. In order to test the activation hypothesis, inferential styles were assessed both before and after a negative cognitive priming questionnaire. Methods. A group of 165 university students completed measures of inferential styles about the self, consequences, and causes before and after completing a negative cognitive priming questionnaire (Time 1). Participants also completed measures of depressive symptoms prior to completing the cognitive priming questionnaire and 5 weeks later (Time 2). Finally, negative events occurring between Time I and Time 2 were assessed. Results. Contrary to the diathesis-stress component of the hopelessness theory, none of the unprimed inferential styles interacted with negative events to predict increases in depressive symptoms. In line with the integration of the hopelessness theory and the activation hypothesis, however, each of the primed inferential styles interacted with negative events to predict increases in depressive symptoms even after controlling for the proportion of variance in depressive symptoms accounted for by the unprimed inferential style x stress interactions. Conclusion. Individuals with depressogenic inferential styles are likely to show increases in depressive symptoms following the occurrence of negative events. At the same time, these depressogenic inferential styles are typically latent cognitive processes that must be primed in order to be accurately assessed.