Longitudinal comorbidity of depression and cognitive impairment has been reported by number of epidemiological studies but the underlying mechanisms explaining the link between affective problems and cognitive decline are not very well understood. Imaging studies have typically investigated patients with major depressive disorder (MDD) and mild cognitive impairment (MCI) separately and thus have not identified a structural brain signature common to these conditions that may illuminate potentially targetable shared biological mechanisms. We performed a meta-analysis of.

48 voxel-based morphometry (VBM) studies of individuals with MDD, MCI, and age-matched controls and demonstrated that MDD and MCI patients had shared volumetric reductions in a number of regions including the insula, superior temporal gyrus (STG), inferior frontal gyrus, amygdala, hippocampus, and thalamus. We suggest that the shared volumetric reductions in the insula and STG might reflect communication deficits and infrequent participation in mentally or socially stimulating activities, which have been described as risk factors for both MCI and MDD. We also suggest that the disease-specific structural changes might reflect the disease-specific symptoms such as poor integration of emotional information, feelings of helplessness and worthlessness, and anhedonia in MDD. These findings could contribute to better understanding of the origins of MDD-MCI comorbidity and facilitate development of early interventions.

许多流行病学研究报告了抑郁症和认知障碍的纵向共病，但解释情感问题和认知能力下降之间联系的潜在机制尚不清楚。影像学研究通常分别调查患有重度抑郁症（MDD）和轻度认知障碍（MCI）的患者，因此尚未确定这些疾病共有的结构性大脑特征，这些特征可能阐明潜在的可靶向的共享生物学机制。我们进行了荟萃分析。

对患有 MDD、MCI 和年龄匹配对照者的 48 项基于体素的形态测量 (VBM) 研究表明，MDD 和 MCI 患者的许多区域都有共同的体积减少，包括岛叶、颞上回 (STG)、额下叶脑回、杏仁核、海马体和丘脑。我们认为，岛叶和 STG 的共同体积减少可能反映了沟通缺陷和不经常参与精神或社交刺激活动，这些已被描述为 MCI 和 MDD 的危险因素。我们还认为，疾病特异性的结构变化可能反映了疾病特异性的症状，例如MDD中情绪信息整合不良、无助感和无价值感以及快感缺乏。这些发现可能有助于更好地了解 MDD-MCI 合并症的起源，并促进早期干预措施的制定。