Justin Riddle1, Morgan L Alexander1, Crystal Edler Schiller2, David R Rubinow2, Flavio Frohlich3. 1. Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Carolina Center for Neurostimulation, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 2. Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 3. Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Carolina Center for Neurostimulation, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Electronic address: flavio_frohlich@med.unc.edu.
Abstract
BACKGROUND: Left frontal alpha oscillations are associated with decreased approach motivation and have been proposed as a target for noninvasive brain stimulation for the treatment of depression and anhedonia. Indeed, transcranial alternating current stimulation (tACS) at the alpha frequency reduced left frontal alpha power and was associated with a higher response rate than placebo stimulation in patients with major depressive disorder (MDD) in a recent double-blind, placebo-controlled clinical trial. METHODS: In this current study, we aimed to replicate successful target engagement by delineating the effects of a single session of bifrontal tACS at the individualized alpha frequency (IAF-tACS) on alpha oscillations in patients with MDD. Eighty-four participants were randomized to receive verum or sham IAF-tACS. Electrical brain activity was recorded during rest and while viewing emotionally salient images before and after stimulation to investigate whether the modulation of alpha oscillation by tACS exhibited specificity with regard to valence. RESULTS: In agreement with the previous study of tACS in MDD, we found that a single session of bifrontal IAF-tACS reduced left frontal alpha power during the resting state when compared with placebo. Furthermore, the reduction of left frontal alpha oscillation by tACS was specific for stimuli with positive valence. In contrast, these effects on left frontal alpha power were not found in healthy control participants. CONCLUSIONS: Together, these results support an important role of tACS in reducing left frontal alpha oscillations as a future treatment for MDD.
BACKGROUND: Left frontal alpha oscillations are associated with decreased approach motivation and have been proposed as a target for noninvasive brain stimulation for the treatment of depression and anhedonia. Indeed, transcranial alternating current stimulation (tACS) at the alpha frequency reduced left frontal alpha power and was associated with a higher response rate than placebo stimulation in patients with major depressive disorder (MDD) in a recent double-blind, placebo-controlled clinical trial. METHODS: In this current study, we aimed to replicate successful target engagement by delineating the effects of a single session of bifrontal tACS at the individualized alpha frequency (IAF-tACS) on alpha oscillations in patients with MDD. Eighty-four participants were randomized to receive verum or sham IAF-tACS. Electrical brain activity was recorded during rest and while viewing emotionally salient images before and after stimulation to investigate whether the modulation of alpha oscillation by tACS exhibited specificity with regard to valence. RESULTS: In agreement with the previous study of tACS in MDD, we found that a single session of bifrontal IAF-tACS reduced left frontal alpha power during the resting state when compared with placebo. Furthermore, the reduction of left frontal alpha oscillation by tACS was specific for stimuli with positive valence. In contrast, these effects on left frontal alpha power were not found in healthy control participants. CONCLUSIONS: Together, these results support an important role of tACS in reducing left frontal alpha oscillations as a future treatment for MDD.
Authors: John P O'Reardon; H Brent Solvason; Philip G Janicak; Shirlene Sampson; Keith E Isenberg; Ziad Nahas; William M McDonald; David Avery; Paul B Fitzgerald; Colleen Loo; Mark A Demitrack; Mark S George; Harold A Sackeim Journal: Biol Psychiatry Date: 2007-06-14 Impact factor: 13.382
Authors: Morgan L Alexander; Sankaraleengam Alagapan; Courtney E Lugo; Juliann M Mellin; Caroline Lustenberger; David R Rubinow; Flavio Fröhlich Journal: Transl Psychiatry Date: 2019-03-05 Impact factor: 6.222