To address a key gap in theorizing and research, we consider relational uncertainty as an explanation for why individuals experiencing depressive symptoms may be reluctant to talk about sensitive issues. We report closed-ended online survey data from 126 romantic couples in which one or both partners had been professionally diagnosed with depression. Results indicated that relational uncertainty mediated the positive association between depressive symptoms and topic avoidance. Partner effects from men to women also emerged. These findings are valuable for identifying relational uncertainty as a mechanism that may explain people's unwillingness to discuss challenging topics when they are experiencing depressive symptoms.