中文摘要：

目的比较发病年龄不同、首次抑郁发作的成年抑郁症患者全脑灰质体积的差异。方法根据发病年龄将101例首次抑郁发作且未服药成年抑郁症患者（患者组）分为：早期发病组（18-29岁，32例）、中期发病组（30-44岁，39例）和晚期发病组（45-60岁，30例）。91例年龄、性别与患者组相匹配的健康志愿者为对照组，并划分为青年期对照组（18-29岁，32例），中年期对照组（30-44岁，30例）和老年期对照组（45-60岁，29例）。所有参与者均完成脑部结构MRI扫描，采用基于体素的形态学方法分析所有的影像学数据。结果早期发病组左侧丘脑、右侧舌回和楔叶及小脑Ⅵ灰质体积比青年期对照组减小（t=-4.26--3.58，均P〈0.01），右侧角回比青年期对照组增大（t=4.45，P〈0.01）；中期发病组右侧额中回灰质体积比中年期对照组减小（t=-3.62，P〈0.01）；晚期发病组右侧颞中回、右侧舌回、左侧梭状回及双侧小脑Ⅸ区灰质体积比老年期对照组减小（t=-4.87--3.91，P〈0.01），右侧杏仁核比老年期对照组增大（t=3.36，P〈0.01）。全因子模型分析显示，患者组组内右侧额中回（t=7.40）及右侧小脑Crus1区（t=7.20）灰质体积差异有统计学意义（P〈0.005,未校正）。早期和中期发病患者的全脑灰质体积与疾病严重程度正相关（r=0.553-0.641，均P〈0.01），晚期发病患者全脑灰质体积与疾病严重程度负相关（r=-0.626，P〈0.01）。结论抑郁症患者存在边缘系统-皮质-纹状体-苍白球-丘脑环路相关的脑灰质体积减小；不同年龄发病的成年抑郁症患者全脑灰质体积改变不一致；不同年龄起病的成年抑郁症患者可能存在不同的病理生理学机制。

英文摘要：

Objective To compare the whole brain grey matter volume （GMV） in first-episode major depressive disorder （MDD） with different age-onset. Methods 101 first-episode, drug-naive depressive patients were divided into three groups on the basis of age of MDD onset： 32 patients with early adult onset depression （18-29 years, EOD）, 39 patients with middle age onset depression （30-44 years, MOD）, and 30 patients with late adult onset depression （45-60 years, LOD）. A total of 91 healthy controls （HCs）,well matched by age and gender, were also collected into three groups： the 32 young HCs （18-29 years）, the 30 middle-aged HCs （30-44 years）, and the 29 late onset HCs （45-60 years）. Magnetic resonance imaging was conducted on all subjects. The voxel-based morphometry （VBM） approach was employed to analyze the images. Results Compared to young HCs, the EOD group showed decreased GMV in the left thalamus, right lingual gyrus, right cuneus and cerebellum VI （t=-4.26- -3.58, all P〈0.01 ）, and increased GMV in right angular gyms （t=4.45, P〈0.01）. Compared to middle-aged HCs, the MOD group showed decreased GMV in the right middle frontal gyrus （t=-3.62, P〈0.01 ）. Compared to late onset HCs, the LOD group exhibited decreased GMV in the right middle temporal gyrus, right lingua/gyrus, left fusiform gyrus and bilateral cerebellum IX （t=-4.87- -3.91, P〈0.01 ）, but an increased right amygdala （t=3.36, P〈0.01 ）. The full factorial analysis revealed that the right middle frontal gyrus （t=7.40） and right cerebellum Crusl （t=7.20） were significantly different among the three patient subgroups （P〈0.005,unadjusted）. The whole brain GMV of EOD and MOD subgroups positively correlated with the symptom severity （r=0.553-0.641, P〈 0.01 ）, while the whole brain GMV of LOD subgroup negatively correlated with their symptom severity （r=-0.626, P〈0.01）. Conclusions Individuals with MDD may have the GMV reduced in the limbic-cortical-striatal-pallidal-tha