Study M324

Study name

Dubin MJ 2016

Title

Elevated prefrontal cortex GABA in patients with major depressive disorder after TMS treatment measured with proton magnetic resonance spectroscopy

Overall design

In this naturalistic study, we assessed the effect of 10-Hz rTMS over the left dorsolateral prefrontal cortex (DLPFC) of patients with major depressive disorder on the levels of medial prefrontal cortex (MPFC) gamma-aminobutyric acid (GABA) and the combined resonance of Glx as assessed in vivo with proton magnetic resonance spectroscopy (1H MRS). Currently depressed individuals between the ages of 23 and 68 years participated in a 5-week naturalistic, open-label treatment study of rTMS, with 1H MRS measurements of MPFC GABA and Glx levels at baseline and following 5 weeks of the rTMS intervention. rTMS pulses were applied over the left DLPFC at 10 Hz and 80% - 120% of motor threshold for 25 daily sessions, with each session consisting of 3000 pulses. Therapeutic response was assessed using the 24-item Hamilton Rating Scale for Depression (HAMD-24). In the aggregate, 25 patients with treatment-resistant depression were enrolled in this study, and all completed the 5-week course of rTMS. Two patients were excluded from all the analyses, leaving 23 outpatients for subsequent analyses. A TMS responder was defined as having at least a 50% reduction in HAMD24 scores post-TMS compared with baseline. Using this criteria, 8 were TMS responders, and 15 were TMS nonresponders. Metabolite quantification was reported relative to brain water concentration.

Study Type

Type2;

Type4;

Data available

Unavailable

Organism

Human;

Categories of depression

Depressive disorder; Treatment-resistant depression; Treatment-resistant depression;

Criteria for depression

DSM-IV-TR diagnosed MDD, HAMD-24 >= 18

Sample size

23

Tissue

Central; Brain; Medial prefrontal cortex;

Platform

MRS; MRS: 3.0 T GE MR system;

PMID

26900793

DOI

10.1503/jpn.150223

Citation

Dubin MJ, Mao X, Banerjee S, et al. Elevated prefrontal cortex GABA in patients with major depressive disorder after TMS treatment measured with proton magnetic resonance spectroscopy. J Psychiatry Neurosci 2016;41(3):E37-45.

Metabolite

Gamma-Aminobutyric acid;