Department of Magnetic Resonance Imaging, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Key Laboratory for Functional Magnetic Resonance Imaging and Molecular Imaging of Henan Province, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Psychol Med. 2023 Apr;53(5):2146-2155. doi: 10.1017/S0033291721003986. Epub 2021 Sep 29.
As a neuroprogressive illness, depression is accompanied by brain structural abnormality that extends to many brain regions. However, the progressive structural alteration pattern remains unknown.
To elaborate the progressive structural alteration of depression according to illness duration, we recruited 195 never-treated first-episode patients with depression and 130 healthy controls (HCs) undergoing T1-weighted MRI scans. Voxel-based morphometry method was adopted to measure gray matter volume (GMV) for each participant. Patients were first divided into three stages according to the length of illness duration, then we explored stage-specific GMV alterations and the causal effect relationship between them using causal structural covariance network (CaSCN) analysis.
Overall, patients with depression presented stage-specific GMV alterations compared with HCs. Regions including the hippocampus, the thalamus and the ventral medial prefrontal cortex (vmPFC) presented GMV alteration at onset of illness. Then as the illness advanced, others regions began to present GMV alterations. These results suggested that GMV alteration originated from the hippocampus, the thalamus and vmPFC then expanded to other brain regions. The results of CaSCN analysis revealed that the hippocampus and the vmPFC corporately exerted causal effect on regions such as nucleus accumbens, the precuneus and the cerebellum. In addition, GMV alteration in the hippocampus was also potentially causally related to that in the dorsolateral frontal gyrus.
Consistent with the neuroprogressive hypothesis, our results reveal progressive morphological alteration originating from the vmPFC and the hippocampus and further elucidate possible details about disease progression of depression.
抑郁症是一种神经进行性疾病，伴随着延伸到许多脑区的大脑结构异常。然而，其进行性结构改变模式仍不清楚。
为了详细阐述抑郁症根据疾病持续时间的进行性结构改变，我们招募了 195 名从未接受过治疗的首发抑郁症患者和 130 名接受 T1 加权 MRI 扫描的健康对照者（HCs）。采用基于体素的形态计量学方法测量每个参与者的灰质体积（GMV）。首先根据疾病持续时间将患者分为三个阶段，然后使用因果结构协变网络（CaSCN）分析来探索特定阶段的 GMV 改变及其因果关系。
总体而言，与 HCs 相比，抑郁症患者表现出特定阶段的 GMV 改变。包括海马体、丘脑和腹内侧前额叶皮质（vmPFC）在内的区域在疾病发作时出现 GMV 改变。随着疾病的进展，其他区域开始出现 GMV 改变。这些结果表明 GMV 改变起源于海马体、丘脑和 vmPFC，然后扩展到其他脑区。CaSCN 分析的结果表明，海马体和 vmPFC 共同对伏隔核、楔前叶和小脑等区域施加因果效应。此外，海马体的 GMV 改变也可能与背外侧额回的 GMV 改变存在因果关系。
与神经进行性假说一致，我们的结果揭示了起源于 vmPFC 和海马体的进行性形态改变，并进一步阐明了抑郁症进展的可能细节。
