Background: Magnetic resonance spectroscopy (MRS) has been used to identify gamma-aminobutyric acid (GABA) alterations in mood disorders. particularly in the medial prefrontal cortex (mPFC) where decreased concentrations have been associated with anhedonia. In major depressive disorder (MDD). prior work suggests that repetitive transcranial magnetic stimulation (rTMS) increases mPFC G... https://www.roneverhart.com/Echo-Fix-EF-P2-Spring-Reverb-Pedal-p32083/