rTMS for Depressed Teens: A Sham-Controlled Trial, Part 2

Part 2 of the study aims to: * Evaluate the benefit of daily, active, open-label rTMS in Part 1 non-responders. * Evaluate the benefits of bi-weekly, active, open-label maintenance rTMS treatment for Part 1 responders over the course of 12 months post acute treatment. * Evaluate, by proton magnetic resonance spectroscopy (1H-MRS) at 3 Tesla(3T), neurometabolic biomarkers at the beginning and end of each study phase. * Define regional specificity \[anterior cingulate (AC) and left dorsolateral prefrontal cortex (L-DLPFC)\] of cerebral metabolites (i.e. glutamate and glutamine) in adolescent depression. * Study whether specific neurochemical resonances are associated with response, remission, and/or maintenance of improvement of clinical depressive symptoms when rTMS is used to treat adolescent depression.