抑郁障碍（MDD）、伴混合特征的抑郁障碍（MDD-MF）和双相障碍（BD-MF）、双相障碍（BD）构成连续性情感障碍谱系，揭示其诊断和鉴别的客观依据是精准医疗领域的热点。皮层-边缘系统-纹状体（CIS）神经环路结构和功能异常是MDD和BD患者的差异神经影像标志，然而，MDD-MF和BD-MF的神经影像特征尚不清楚。在前期工作基础上，本项目拟研究MDD-MF和BD-MF在CIS神经环路上是否存在可鉴别两者的特异性神经影像特征，并探讨是否与MDD和BD的神经影像特征具有连续谱系变化。具体而言，本项目拟（1）基于CIS神经环路研究MDD-MF和BD-MF的差异神经影像特征，构建可鉴别两者的模型；（2）利用相似度算法研究MDD、MDD-MF、BD-MF、BD神经影像特征的相似性，阐述连续情感障碍谱系中疾病的神经影像特征变化关系。期望本项目的研究成果能为情感障碍谱系疾病的早期诊断和治疗提供客观依据。

The diagnosis of mixed features in major depressive disorder (MDD-MF) and bipolar disorder (BD-MF) constructs a continuum ranging from pure major depressive disorder (MDD) to pure bipolar disorder (BD). It is important to investigate the objective evidence for diagnosis and recognition of the mood disorder disease in the field of precision medicine. For neuroimaging mechanisms, functional and structural alterations in cortical-limbic-striatal (CIS) neural circuit are neuroimaging biomarkers for the MDD and BD patients. However, it is unclear to the neuroimaging mechanisms for the MDD-MF and BD-MF, which are in the middle of the mood disorder spectrum. Therefore, whether there are specific neuroimaging characteristics in the CIS, could be used to recognize the MDD-MF and BD-MF? Whether the alteration of the neuroimaging characteristics for the MDD-MF, BD-MF, MDD and BD patients is continuum? In order to clarify these issues, this study aims to (1) investigate the differential neuroimaging characteristics between the MDD-MF and BD-MF in the CIS, and construct a machine learning model to recognize them; (2) investigate the similarity of brain structural and functional features within MDD, MDD-MF, BD-MF and BD patients, and explain the relationship of the alteration of the neuroimaging characteristics for the disease among the mood disorder spectrum. The findings obtained in this project will provide objective evidence for early diagnosis and treatment for the disease among the mood disorder spectrum.