中文摘要：

目的通过PET／CT观察并测量首发与复发抑郁症患者各脑区神经细胞18F-氟代脱氧葡萄糖（18F-FDG）摄取及代谢的差异，以探讨这两种抑郁症潜在发病机制的区别。方法对自2014年1月至2016年1月江苏大学附属医院精神科门诊的35例首发抑郁症患者（首发抑郁组）、35例复发抑郁症患者（复发抑郁组）及35例健康志愿者（正常组），静脉注射。SF—FDG后经PET／CT采集各脑区葡萄糖摄取数据，通过统计参数图（SPM）软件分析出存在摄取差异的脑区，确定这两种抑郁症重叠的摄取差异脑区后再测量葡萄糖的动态代谢清除率并进行对比。结果与正常组对比．首发抑郁组双侧额叶扣带回、左侧纹状体、双侧海马、右侧丘脑、左侧额中回、左侧颞中回及右侧颞上回的葡萄糖摄取减低；与正常组对比，复发抑郁组双侧额叶扣带回、双侧纹状体、双侧海马、右侧丘脑、左侧额上回、右侧颞中回、左侧颞下回及右侧舌回的葡萄糖摄取减低。在重叠的摄取差异脑区中．与首发抑郁症组对比。复发抑郁症组左侧额叶扣带回及左侧海马的60～80min、60～100min葡萄糖代谢清除率明显减低，差异均有统计学意义（P〈0．05）。结论首发与复发抑郁症患者多个脑区都出现了18F-FDG摄取障碍，这两种抑郁症存在重叠的摄取差异脑区，其中复发抑郁症出现了左侧额叶扣带回及左侧海马18F-FDG代谢减缓，而这种神经细胞对葡萄糖能量运用的障碍可能就是这两种抑郁症潜在发病机制的区别之一。

英文摘要：

Objective To explore the differences of two types of depressions through observing brain nerve cells metabolism of 18F-fludeoxyglucose （18F-FDG） uptake and utilization in the first-episode depression patients and recurrent depression patients. Methods Thirty-five first-episode depression patients, 35 recurrent depression patients and 35 healthy volunteers, collected in our hospital from January 2014 to January 2016, were chosen in our study; intravenous injection of 18F-FDG was performed, and the glucose uptake data in various brain regions were collected by PET/CT; the brain regions with different absorption were analyzed through SPM soflnvare; dynamic metabolic rate of glucose after identifying the overlapping absorb different brain regions in these two types of depression was measured and compared. Results As compared with that in the healthy control group, the glucose uptake in the bilateral cingulate gyrus, the left striatum, the bilateral hippocampus, the right thalamus, the left middle frontal gyrus, the left middle temporal gyrus and the right superior temporal gyrus were decreased in the first-episode depression group. As compared with that in the healthy control group, the glucose uptake in the bilateral cingulate gyrus, the bilateral striatum, the bilateral hippocampus, the right thalamus, the left superior frontal gyrus, the right middle temporal gyrus, the left inferior temporal gyrus and the right lingual gyrus were decreased in the recurrent depression group. As compared with those in the first-episode depression group, the metabolic clearance rates at 60-80 min and 60-100 min in the left cingulate gyrus and left hippocampus were significantly decreased in the recurrent depression （P〈0.05）. Conclusion The disorder of 18F-FDG uptake appears in multiple brain regions in the first-episode depression and recurrent depression patients; there are some overlap regions; the ISF-FDG metabolism rate decreases in the left cingulate gyrus and left hippocampus in the recurrent depression, the glucose