阿尔茨海默病（Alzheimer’s disease，AD）常伴随多种神经精神症状，其中抑郁症状尤为常见，甚至可以出现在临床前期。本文系统综述了抑郁症状（包括亚综合征性抑郁）与AD相关认知障碍之间的复杂关联，并重点探讨了海马等AD特征性脑区在其中的潜在作用。现有研究证据表明，抑郁症状可能通过促进关键脑区萎缩、影响神经可塑性以及加剧β-淀粉样蛋白（amyloid β-protein，Aβ）沉积等多种途径，加速认知衰退的进程。未来研究应进一步结合多模态神经影像技术与非侵入性生物标志物，以期为AD高危人群的早期识别及精准干预提供新的理论依据和临床靶点。

Alzheimer's Disease (AD) is often accompanied by various neuropsychiatric symptoms, among which depressive symptoms are particularly common and may even appear in the preclinical stage. This paper systematically reviews the complex relationship between depressive symptoms (including subsyndromal symptomatic depression) and AD-related cognitive impairment, with a focus on the potential role of AD-characteristic brain regions such as the hippocampus. Current evidences have suggested that depressive symptoms may accelerate the progression of cognitive decline through various pathways, such as promoting brain atrophy of key brain regions, affecting neuroplasticity, and exacerbating the deposition of amyloid β-protein (Aβ). Future research should further integrate multimodal neuroimaging techniques with non-invasive biomarkers, in order to provide new theoretical basis and clinical targets for early identification and precise intervention of AD in high-risk populations.