Major depression in adolescents is prevalent, of significant public health importance, and a prime candidate for innovation in treatment. Improvements in the treatment of adolescent depression should have both a strong public health impact and important economic impact. In 1998, TADS was initiated under the National Institute of Mental Health to empirically evaluate the relative short and longer-term effectiveness of treatments for adolescents suffering from major depressive disorder (MDD). TADS is a multicenter, randomized, masked effectiveness trial designed to evaluate the short-term (12-week) and long-term (36-week) effectiveness of four treatments for adolescents with MDD. This report describes the design of the trial, the rationale for the design choices made, and the methods used to carry out the trial. TADS is an effort to improve the treatment of adolescent depression and related outcomes and represents an important building block in efforts to assemble a comprehensive, public health approach to the treatment of depressed youth. References