title: Metabolic alterations in the dorsolateral prefrontal cortex after treatment with high-frequency repetitive transcranial magnetic stimulation in patients with unipolar major depression.
abstract: Neuroimaging studies suggest a specific role of anterior cingulate cortex (ACC) and left dorsolateral prefrontal cortex (DLPFC) in major depression. Stimulation of the latter by means of repetitive transcranial magnetic stimulation (rTMS) as an antidepressant intervention has increasingly been investigated in the past. The objective of the present study was to examine in vivo neurochemical alterations in both brain regions in 17 patients with unipolar major depression before and after 10 days of high-frequency (20Hz) rTMS of the left DLPFC using 3-tesla proton magnetic resonance spectroscopy. Six out of seventeen patients were treatment responders, defined as a 50% reduction of the Hamilton depression rating scale. No neurochemical alterations in the ACC were detected after rTMS. As compared to the non-responders, responders had lower baseline concentrations of DLPFC glutamate which increased after successful rTMS. Correspondingly, besides a correlation between clinical improvement and an increase in glutamate concentration, an interaction between glutamate concentration changes and stimulation intensity was observed. Our results indicate that metabolic, state-dependent changes within the left DLPFC in major depressive disorder involve the glutamate system and can be reversed in a dose-dependent manner by rTMS.
authors.affiliation: Department of Psychiatry, Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Eschenallee 3, D-14050 Berlin, Germany. alexander.luborzewski@charite.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Luborzewski
authors.forename: Florian
authors.initials: F
authors.lastname: Schubert
authors.forename: Frank
authors.initials: F
authors.lastname: Seifert
authors.forename: Heidi
authors.initials: H
authors.lastname: Danker-Hopfe
authors.forename: Eva-Lotta
authors.initials: EL
authors.lastname: Brakemeier
authors.forename: Peter
authors.initials: P
authors.lastname: Schlattmann
authors.forename: Ion
authors.initials: I
authors.lastname: Anghelescu
authors.forename: Michael
authors.initials: M
authors.lastname: Colla
authors.forename: Malek
authors.initials: M
authors.lastname: Bajbouj
mesh_terms: D000328:Adult; D001931:Brain Mapping; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010555:Personality Inventory; D017397:Prefrontal Cortex / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation
chemical_list: D018698:Glutamic Acid