This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. This project is designed to test the hypothesis that developmental mechanisms underlie the etiology and poor outcomes of pediatric major depressive disorder (MDD). Through an integrative approach, we propose to use a 2x2 study design examine development within cortico-limbic networks in younger and older adolescents, with and without MDD. We propose to obtain neuroimaging data including stuctural, diffusion tensor, resting functional, and spectropscopic imaging. Since we have proposed to limit our depressed subjects to those who are treatment-naive, we request 12 months to collect this pilot data.