The Treatment for Adolescents With Depression Study (TADS) evaluated the short- and long-term effectiveness of cognitive behavior therapy (CBT) alone, fluoxetine alone, and their combination, relative to pill placebo, and the 12-week treatment effects were recently published (TADS Team, 2004). Results showed that treatment that combined CBT with fluoxetine was significantly more effective than fluoxetine alone or CBT alone or pill placebo. Combining CBT with fluoxetine also provided a protective effect on the slightly increased risk of harm-related events associated with fluoxetine alone compared to placebo (TADS Team, 2004). In this protocol, CBT treatment included individual CBT sessions with the adolescent as well as parent psychoeducation sessions and parent-teen conjoint sessions. The present article describes the background and rationale for the parent component of the TADS CBT treatment. It also describes the 2 parent psychoeducation sessions and the 5 parent-teen conjoint sessions that were available in this modularized treatment protocol. In addition, the boundaries of the parent component are presented; these boundaries differentiate parent-teen conjoint sessions from a broader family systems approach. Finally, challenges to the effectiveness of parent involvement in TADS CBT treatment are described and include parent engagement, parent psychopathology, working with divorced parents and parents from a variety of family constellations and cultural backgrounds. Within a modular, manualized treatment protocol, flexible attention to these very real issues is essential in engaging and retaining.