The contrast-avoidance model (CAM) originally described emotion-regulation patterns in generalized anxiety disorder (GAD), proposing that chronic worry maintains negative emotionality, thus attenuating strong shifts into negative emotion (emotional contrasts) as a result of adverse events. Rumination may function similarly in depression, although this proposal requires further research. In this study, we aimed to (a) test the transdiagnostic applicability of the CAM and (b) enhance ecological validity of the CAM using personally relevant in vivo exposures. Participants were assigned to worry, rumination, relaxation, or neutral inductions, then engaged in a challenging task followed by false-negative performance feedback. Relative to baseline, worry and rumination both increased negative emotionality, which significantly reduced emotional contrast in response to failure feedback. Furthermore, participants in the GAD-analogue group experienced prior worry as helpful in coping with failure feedback, and participants in the MDD-analogue group reported rumination as helpful relative to comparison inductions. Overall, findings support the transdiagnostic application of CAM.