The goal of this study is to lay the groundwork for the later development of prevention programs for persons with cyclothymia and dysthymia. These prevention programs would be designed to reduce the risk of persons with cyclothymia and dysthymia from developing incapacitating major affective disorders. Several treatment programs have been developed, most notably congnitive-behavioral and social skills therapies, which appear to offer effective symptom reduction for persons with major affective disorders. It is not clear, however, whether these models can be directly adapted to the preventive treatment of cyclothymia and dysthymia, two conditions which predispose or place persons at risk for the later development of major depressive episodes. In order to gather information necessary to develop effective interventions, this study will investigate the natural history of cyclothymia and dysthymia, focusing particular attention on the methods used by cyclothymic and dysthymic subjects to deal with everyday stresses. Previous research by the author indicates that college undergraduates make up a viable pool for investigating questions of cyclothymic and dysthymic stress response. Subjects will be initially identified on the basis of their responses to a self-report questionnaire, the General Behavior Inventory and diagnosis will be confirmed with a structured diagnostic interview. Forty cyclothymics and dysthymics and twenty normal control subjects will be recruited to report daily variations in mood quality and intensity. Subjects will also complete three structured interviews which will review their cognitive, behavioral, emotional, and social responses to everyday stresses. Together, these measures will provide a profile of adaptive and maladaptive styles of coping in persons with considerable mood variability (cyclothymics and dysthymics) and in normal college students. These data will provide valuable information for the targeted development of prevention programs for these populations at risk.