Multimorbidity and depression are complex multifactorial conditions with major implications for older individuals, their families, and healthcare providers. In this scoping review, we aimed to 1) review findings from longitudinal epidemiological studies investigating the association between multimorbidity and depression; 2) identify potential mechanisms linking multimorbidity and depression; 3) discuss challenges to advance the research field. Overall, evidence emerging from longitudinal studies supports a bidirectional association between the two conditions, although studies are methodologically heterogeneous in terms of design, inclusion criteria, measurement of multimorbidity and depression, and length of follow-up. A variety of biological, psychosocial, and care-related drivers may regulate the transition from multimorbidity to depression, and the other way around, although these mechanisms are yet to be explicitly verified. Further research is required to unravel the intricate interplay between multimorbidity, depression, their common drivers, and precipitating factors underlying the relationship between the two conditions. Understanding these processes will inform strategies aimed at promoting mental and physical health during aging.

多发病和抑郁症是复杂的多因素疾病，对老年人、他们的家人和医疗保健提供者有重大影响。在本次范围界定审查中，我们旨在 1) 审查调查多发病与抑郁之间关联的纵向流行病学研究的结果；2) 确定将多种疾病和抑郁症联系起来的潜在机制；3) 讨论推进研究领域的挑战。总体而言，纵向研究中出现的证据支持这两种情况之间存在双向关联，尽管研究在设计、纳入标准、多重疾病和抑郁症的测量以及随访时间方面在方法上存在异质性。各种生物、社会心理和护理相关的驱动因素可能会调节从多重疾病到抑郁症的转变，反之亦然，尽管这些机制尚未得到明确验证。需要进一步的研究来解开多种疾病、抑郁症、它们的共同驱动因素以及导致这两种情况之间关系的潜在因素之间错综复杂的相互作用。了解这些过程将为旨在促进衰老过程中身心健康的策略提供信息。