In order to more fully understand the abnormalities in emotional responding associated with adolescent depression we examined clinically depressed and non-depressed adolescents’ physiological responses to their parents’ negative emotional behavior, as indexed by their heart rate responses to parental angry and dysphoric behavior during laboratory-based interactions. Maternal angry and dysphoric behavior predicted heart rate deceleration amongst non-depressed adolescents, a response that was not observed in
depressed adolescents. Fathers’ angry behavior predicted signiﬁcant heart rate acceleration in depressed (but not non-depressed) adolescents, whereas fathers’ dysphoric behavior predicted heart rate deceleration amongst depressed but not amongst non-depressed adolescents. These ﬁndings are interpreted within the framework of orienting and defense cardiac responses, and suggest that reactivity in adolescent depression is characterized by the absence of a normative orienting response toward aversive maternal behaviors, and a defensive physiological response to aggressive paternal behavior.