Kim Junhyung, Kim Yong-Ku
Department of Psychiatry, Korea University Guro Hospital, Korea University College of Medicine, Seoul 08308, Korea.
Department of Psychiatry, Yonsei University College of Medicine, Seoul 03080, Korea.
Biomedicines. 2021 Jan 16;9(1):82. doi: 10.3390/biomedicines9010082.
Alzheimer's disease (AD) is the most common type of dementia, and depression is a risk factor for developing AD. Epidemiological studies provide a clinical correlation between late-life depression (LLD) and AD. Depression patients generally remit with no residual symptoms, but LLD patients demonstrate residual cognitive impairment. Due to the lack of effective treatments, understanding how risk factors affect the course of AD is essential to manage AD. Advances in neuroimaging, including resting-state functional MRI (fMRI), have been used to address neural systems that contribute to clinical symptoms and functional changes across various psychiatric disorders. Resting-state fMRI studies have contributed to understanding each of the two diseases, but the link between LLD and AD has not been fully elucidated. This review focuses on three crucial and well-established networks in AD and LLD and discusses the impacts on cognitive decline, clinical symptoms, and prognosis. Three networks are the (1) default mode network, (2) executive control network, and (3) salience network. The multiple properties emphasized here, relevant for the hypothesis of the linkage between LLD and AD, will be further developed by ongoing future studies.
阿尔茨海默病（AD）是最常见的痴呆类型，而抑郁症是患AD的一个风险因素。流行病学研究揭示了晚年抑郁症（LLD）与AD之间的临床关联。抑郁症患者通常会康复且无残留症状，但LLD患者会表现出残留的认知障碍。由于缺乏有效的治疗方法，了解风险因素如何影响AD的病程对于管理AD至关重要。神经影像学的进展，包括静息态功能磁共振成像（fMRI），已被用于研究导致各种精神疾病临床症状和功能变化的神经系统。静息态fMRI研究有助于理解这两种疾病，但LLD与AD之间的联系尚未完全阐明。本综述聚焦于AD和LLD中三个关键且已明确的网络，并讨论其对认知衰退、临床症状和预后的影响。这三个网络分别是：（1）默认模式网络，（2）执行控制网络，以及（3）突显网络。本文所强调的与LLD和AD之间联系假说相关的多个特性，将在未来持续的研究中得到进一步发展。
