This study examined depressive and positive patterns of interactions among clinical and nonclinical adolescent peers within an interpersonal context. Ten clinical dyads with a depressed partner and 10 nonclinical dyads engaged in 16-min audiotaped conversations under positive and negative task instructions discussing positive and negative experiences. Conversations were unitized and coded according to depressive, aggressive, positive, and neutral behaviors. The clinical dyad-group demonstrated over two times more depressive behaviors than did the nonclinical dyad-group. Both dyad-groups exhibited increased depressive interactions during negative task instructions and increased positive interaction during positive task instructions. The loglinear approach to sequential analysis demonstrated significant overall bidirectional influence in the adolescents' dyadic interaction. Specifically, we found that the depressed adolescents' depressive behaviors decreased the likelihood of partners' aggressive behaviors, and increased the likelihood of partners' positive behaviors. Clinical and nonclinical dyad-groups showed reliable patterns of positive interaction sequences. Results demonstrate that depressive and positive behaviors are functional in adolescent dyadic interaction.