Institution: | 1. Mental Health Institute, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China;2. Department of Radiology, Hunan General Hospital, Changsha, Hunan, China;3. Department of Radiology, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China;4. Chinese University of Hong Kong, Hong Kong, China;5. Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, China;6. The Department of Neuropsychiatry and Institute of Neuropsychiatric Research, affiliated ZhongDa Hospital of Southeast University, Nanjing, China;g College of Mathematics, Physics & Information Science, Xinjiang Normal University, Urumqi, China |
Abstract: | BackgroundNeuroimaging studies suggest that the prefrontal cortex (PFC) is involved in the pathophysiology of major depression. Repetitive transcranial magnetic stimulation (rTMS) as an antidepressant intervention has increasingly been investigated in the last two decades. In this study metabolic changes within PFC of severely depressed patients before and after rTMS were evaluated by proton magnetic resonance spectroscopy (1H-MRS).MethodThirty-four young depressed patients with treatment-resistant unipolar depression were enrolled in a double-blind, randomized study〔active ((n = 19) vs. sham(n = 15)), and the PFC was investigated before and after high-frequency (15 Hz) rTMS using 3-tesla proton magnetic resonance spectroscopy. Response was defined as a 50% reduction of the Hamilton depression rating scale. The results were compared with 28 age- and gender-matched healthy controls.ResultsIn depressive patients a significant reduction in myo-inositol (m-Ino) was observed pre-rTMS (p < 0.001). After successful treatment, m-Ino increased significantly in left PFC and the levels no longer differed from those of age-matched controls. In addition to a positive correlation between clinical improvement and an increment in m-Ino ratio, a correlation between clinical improvement and early age onset was observed.ConclusionsOur results support the notion that major depressive disorder is accompanied by state-dependent metabolic alterations, especially in myo-inositol metabolism, which can be partly reversed by successful rTMS. |