Jia Yanbin, Zhong Shuming, Wang Ying, Liu Tao, Liao Xiaoxiao, Huang Li
Department of Psychiatry, First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
Department of Psychiatry, First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
J Affect Disord. 2015 Jul 15;180:162-9. doi: 10.1016/j.jad.2015.04.005. Epub 2015 Apr 10.
Previous neuroimaging studies found evidence of potential brain biochemical abnormalities in patients with major depressive disorder (MDD). Abnormal serum thyroid hormone levels were also found in MDD patients, which may correlated with the abnormal biochemical metabolism of brain. However, they rarely excluded the compounding effects of medication, and brain degeneration. This study sought to investigate the relationship between the biochemical metabolism and the serum thyroid hormone levels in first-episode, treatment-naive, non-late-life patients with MDD.
26 first-episode, treatment-naive, non-late-life patients with MDD and 13 healthy controls were enrolled in this study. Participants underwent two-dimensinal multivoxel proton magnetic resonance spectroscopy ((1)H MRS) [repetition time (TR)=1000ms; echo-time (TE)=144ms] at 1.5T to obtain bilateral metabolite levels from the white matter in prefrontal (WMP) lobe, anterior cingulate cortex (ACC), and hippocampus. The ratios of N-acetylaspartate (NAA)/creatine (Cr) and choline containg compounds (Cho)/creatine (Cr) were calculated. Morning serum free triiodothyronine (FT3), free thyroxin (FT4), total triiodothyronine (T3), total thyroxin (T4), and thyroid-stimulating hormone (TSH) were measured before antidepressant treatment.
On the comparison of brain biochemical changes, MDD patients had a significantly lower NAA/Cr ratio in the left WMP, and lower NAA/Cr and Cho/Cr ratios in the right WMP when compared to the controls. There were no significant differences in the metabolite ratios in the bilateral ACC, and hippocampus. On the comparison of serum thyroid hormone levels, MDD patients had a significantly decreased T3 and TSH levels. On the comparison of correlation of brain biochemical changes and serum thyroid hormone levels in patients with MDD, the NAA/Cr ratio in the right WMP was positively correlated with the level of TSH.
These findings suggest that biochemical abnormalities and thyroid dysfunction may emerge early in the course of MDD. Dysfunction of neuronal function in the WMP may correlate with the abnormal TSH in patients with MDD, which may be related to the neuropathology of depression.
既往神经影像学研究发现重度抑郁症（MDD）患者存在潜在脑生化异常的证据。MDD患者还存在血清甲状腺激素水平异常，这可能与脑生化代谢异常相关。然而，这些研究很少排除药物及脑退变的复合效应。本研究旨在探讨首发、未治疗、非老年MDD患者脑生化代谢与血清甲状腺激素水平之间的关系。
本研究纳入了26例首发、未治疗、非老年MDD患者及13名健康对照者。参与者在1.5T行二维多体素质子磁共振波谱分析（(1)H MRS）[重复时间（TR）=1000ms；回波时间（TE）=144ms]，以获取前额叶白质（WMP）、前扣带回皮质（ACC）及海马的双侧代谢物水平。计算N-乙酰天门冬氨酸（NAA）/肌酸（Cr）及含胆碱化合物（Cho）/肌酸（Cr）的比值。在抗抑郁治疗前测定早晨血清游离三碘甲状腺原氨酸（FT3）、游离甲状腺素（FT4）、总三碘甲状腺原氨酸（T3）、总甲状腺素（T4）及促甲状腺激素（TSH）。
在脑生化变化比较方面，与对照组相比，MDD患者左侧WMP的NAA/Cr比值显著降低，右侧WMP的NAA/Cr及Cho/Cr比值降低。双侧ACC及海马的代谢物比值无显著差异。在血清甲状腺激素水平比较方面，MDD患者的T3及TSH水平显著降低。在MDD患者脑生化变化与血清甲状腺激素水平的相关性比较方面，右侧WMP的NAA/Cr比值与TSH水平呈正相关。
这些发现提示，生化异常及甲状腺功能障碍可能在MDD病程早期出现。WMP中神经元功能障碍可能与MDD患者TSH异常相关，这可能与抑郁症的神经病理学有关。
