The authors examined the effects of depressed affect (DA) on functioning measured by behavioral tasks pertaining to abstract reasoning, social functioning, and delay of gratification in relation to Cluster B personality disorder features (PDs) in a clinical sample. Individuals were randomly assigned to either a DA induction or control condition. Consistent with clinical conceptualizations, the authors expected that Cluster B PD symptoms would be related to maladaptive responding (e.g., poorer delay of gratification) when experiencing DA. As hypothesized, many of the relations between the Cluster B PDs and functioning were moderated by DA (e.g., borderline PD was negatively related to abstract reasoning, but only in the DA condition). However, many of the Cluster B PDs symptom counts were related to more adaptive responses in the DA condition (e.g., less aggressive social functioning, better delay of gratification). The authors speculate that individuals with Cluster B PDs may be more likely to respond maladaptively to alternative negative mood states, such as anger and fear.