MacMaster, FrankJasaui, Yamile2016-11-152016-11-1520162016Jasaui, Y. (2016). Effects of Repetitive Transcranial Magnetic Stimulation and Possible Predictors of Response in Youth with Treatment Resistant Depression (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25831http://hdl.handle.net/11023/3454Adolescents with treatment-resistant depression (TRD) do not respond to conventional antidepressant interventions. Repetitive transcranial magnetic stimulation (rTMS) is a novel therapeutic technique to treat TRD. The left dorsolateral prefrontal cortex (DLPFC), important in emotion regulation and the excitatory neurotransmitter glutamate, are altered in TRD. rTMS applied to the left DLPFC can increase glutamate concentrations in this area. Adolescents (aged 12-21) underwent 3 weeks of rTMS, pre and post magnetic resonance spectroscopy (MRS) to measure glutamate concentrations and weekly Ham-D depression rating scale applications. A 50% reduction in depression scores indicated response to treatment. Depression scores decreased in all participants but declined significantly in responders whose glutamate concentrations pre-treatment were considerably lower. Thus, low glutamate concentrations pre-treatment might be a biomarker of response to rTMS. One explanation for this result is that rTMS stimulates glutamate release, which activates the left DLPFC’s emotional regulation function, which in turn reduces depressive symptomatology.engUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.NeuroscienceMental HealthTreatment-Resistant DepressionGlutamateDorsolateral Prefrontal CortexRepetitive Transcranial Magnetic StimulationMagnetic Resonance Spectroscopymaster thesis10.11575/PRISM/25831