Self-evaluation is mood state dependent. A transient decrease in positive self-evaluation bias may co-occur with sad mood. In clinical depression this decrease is lasting and exaggerated. The act of self-evaluation engages frontal lobe mechanisms of emotion regulation, but it remains unclear how these constraints on cognition become pathological in depression. The goal of the current research is to characterize the neural mechanisms of mood-cognition interaction in self-evaluative decision-making. In four studies, dense array electroencephalography (256 dEEG) was recorded as participants performed a self-appraisal task. Analysis of the event-related potential was closely aligned with psychometric methodology. Findings elaborate on network models of neural self-regulation and depression pathology. Characterization of frontal lobe mechanisms in this context provides insight into the neural basis of adaptive and dysfunctional social behavior.