This study examined effects of an adolescent depression prevention program on maternal criticisms and positive remarks, whether the extent of adolescents' depression accounted for effects, and whether effects of the program on maternal criticisms and positive remarks differed by adolescents' gender. Participants were 298 adolescent (Mage = 14.79, SD = 1.36; 59% female) offspring of mothers with histories of depression; youth were randomized to either a cognitive-behavioral prevention (CBP) program or usual care (UC). At baseline and 9-month postintervention evaluations, mothers were administered the Five-Minute Speech Sample to measure number of criticisms and positive remarks made during an open-ended description of their child and their relationship. Adolescents' depression from pre- through postintervention was assessed with interviews. A hierarchical generalized linear model showed a significant condition-by-gender interaction, indicating that, controlling for baseline criticism, at postintervention mothers of girls in CBP made significantly more criticisms than did mothers of girls in UC, whereas mothers of boys in CBP made fewer criticisms than did mothers of boys in UC. The extent of adolescents' depression from pre- through postintervention partially mediated the relation between intervention condition and mothers' criticisms, for boys but not for girls. Second, controlling for preintervention positive remarks, at postintervention, mothers of youth in CBP made significantly more positive remarks about their child than did mothers of youth in UC, regardless of gender; this relation was not mediated by adolescent depression from pre- through postintervention. We suggest possible explanations for the observed effects of CBP on mothers' criticisms and positive remarks. (PsycInfo Database Record (c) 2020 APA, all rights reserved).