Journal of Family Psychology (Oct 8, 2018). DOI:10.1037/fam0000467 Dyadic interactions may be affected by the mental health of either partner; however, both partners’ symptoms are typically not considered simultaneously in observational studies of parent–child relationships. Using the actor–partner interdependence model (APIM), we examine how depression and posttraumatic stress disorder (PTSD) symptoms in mothers and adolescent daughters predict their own and each other’s relational behaviors (warmth, hostility, communication) during interactions, and whether partners’ relational behaviors predict changes in symptoms 1 month later.. To read the full article, log in using your NHS OpenAthens details.