Study of Repetitive Transcranial Magnetic Stimulation (rTMS) in Depressed Teens

This study aims to: 1. Evaluate the antidepressant effect and safety of rTMS in adolescents meeting criteria for major depressive disorder, single or recurrent episode. 2. Evaluate, by proton magnetic resonance spectroscopy (1H-MRS) at 3 Tesla (3T), the regional specificity \[anterior cingulate (AC) vs. left dorsolateral prefrontal cortex (L-DLPFC)\] of cerebral metabolites (glutamate and glutamine) in adolescent depression and study whether glutamine resonances are associated with response or remission of clinical depressive symptoms when rTMS is used to treat adolescent depression. 3. Evaluate the accuracy of an efficient method for locating the F3 position (i.e., L-DLPFC) through comparison with magnetic resonance imaging (MRI).