Results indicated that preschoolers with higher depression severity scores demonstrated significantly less enthusiasm, persistence, and compliance during mother-child tasks. Preschooler depression severity scores were significantly related to parental emotional support, yet when parental support was controlled statistically, preschoolers’ depression severity was no longer significantly associated with persistence or compliance during dyadic tasks. The relationship between depression severity and enthusiasm during mother-child tasks remained, however. Comprehensive mental health assessments of 150 preschoolers between the ages of 3.0 and 5.6 years produced depression severity scores for all children and DSM-IV diagnoses placing the preschoolers in 1 of 3 groups: depression, disruptive, and healthy. Mothers were interviewed about their children’s moods and behaviors and then mother-dyad interactions were observed using a semistructured videotaped observational measure of parent-child interactions known as the Teaching Task. Videotaped interactions were analyzed for three child behaviors (enthusiasm, persistence, and compliance) and one parental behavior (mother’s expression of positive regard and emotional support to the child during tasks). Clinical implications are discussed regarding the expression of both external relational and internal child factors in preschool depression. Future research should investigate the directionality and casual mechanisms of the variables influencing preschool depression. Tables, references