Three studies assessed the impact of generalized expectancies for negative mood regulation on the severity of depression individuals experience following the end of a romantic relationship. The Negative Mood Regulation Scale (NMR) measured these expectancies. In Study 1 (n = 583), the NMR predicted college students' reports of initial depression in the first week after the relationship ended. Study 2 (n = 114) demonstrated that subjects with higher expectancies used active coping strategies more than those with lower expectancies. Study 3 (n = 78) provided prospective data that showed subjects' NMR scores to predict initial depression in the first week after a relationship ended--when that relationship ended subsequent to their taking the NMR. Results support the importance of expectancies for negative mood regulation as determinants of emotional reactions to distressing events, and they support the validity of the NMR.