Hamilton J P, Siemer M, Gotlib I H
Department of Psychology, Stanford University, Stanford, CA 94305, USA.
Mol Psychiatry. 2008 Nov;13(11):993-1000. doi: 10.1038/mp.2008.57. Epub 2008 May 27.
Major depressive disorder has been associated with volumetric abnormality in the amygdala. In this meta-analysis we examine results from magnetic resonance imaging volumetry studies of the amygdala in depression in order to assess both the nature of the relationship between depression and amygdala volume as well as the influence of extraexperimental factors that may account for significant variability in reported findings. We searched PubMed and ISI Web of Knowledge databases for articles published from 1985 to 2008 that used the wildcard terms 'Depress*' and 'Amygdal*' in the title, keywords or abstract. From the 13 studies that met inclusion criteria for our meta-analysis, we calculated aggregate effect size and heterogeneity estimates from amygdala volumetric data; we then used meta-regression to determine whether variability in specific extraexperimental factors accounted for variability in findings. The lack of a reliable difference in amygdala volume between depressed and never-depressed individuals was accounted for by a positive correlation between amygdala volume differences and the proportion of medicated depressed persons in study samples: whereas the aggregate effect size calculated from studies that included only medicated individuals indicated that amygdala volume was significantly increased in depressed relative to healthy persons, studies with only unmedicated depressed individuals showed a reliable decrease in amygdala volume in depression. These findings are consistent with a formulation in which an antidepressant-mediated increase in levels of brain-derived neurotrophic factor promotes neurogenesis and protects against glucocorticoid toxicity in the amygdala in medicated but not in unmedicated depression.
重度抑郁症与杏仁核的体积异常有关。在这项荟萃分析中，我们研究了抑郁症患者杏仁核的磁共振成像体积测量研究结果，以评估抑郁症与杏仁核体积之间关系的本质，以及可能导致报告结果存在显著差异的实验外因素的影响。我们在PubMed和ISI Web of Knowledge数据库中搜索了1985年至2008年发表的文章，这些文章在标题、关键词或摘要中使用了通配符术语“Depress*”和“Amygdal*”。从符合我们荟萃分析纳入标准的13项研究中，我们根据杏仁核体积数据计算了总体效应大小和异质性估计值；然后我们使用荟萃回归来确定特定实验外因素的差异是否能解释研究结果的差异。抑郁症患者与从未患过抑郁症的个体之间杏仁核体积缺乏可靠差异，这是由杏仁核体积差异与研究样本中接受药物治疗的抑郁症患者比例之间的正相关所导致的：虽然仅包括接受药物治疗个体的研究计算出的总体效应大小表明，与健康人相比，抑郁症患者的杏仁核体积显著增加，但仅针对未接受药物治疗的抑郁症患者的研究显示，抑郁症患者的杏仁核体积可靠地减小。这些发现与一种说法一致，即抗抑郁药介导的脑源性神经营养因子水平升高促进了神经发生，并在接受药物治疗而非未接受药物治疗的抑郁症患者中保护杏仁核免受糖皮质激素毒性的影响。
