Abstract: Background There is evidence showing that multimorbidity is associated with brain health among the elderly. Limited studies examined the combined impacts of physical and mental diseases on cognition performance. Objective This study aims to explore the relationship between mental-physical multimorbidity and cognitive decline in middle-aged and older adults in China，India and Indonesia. Methods This study was based on three national-representative data from China （China Health and Retirement Longitudinal Study），India（Longitudinal Aging Study in India），and Indonesia（Indonesian Family Life Survey），with a total sample of 73，119 respondents. Three domains of cognitive function were considered in the analysis，including time orientation，word recall，and numeracy. Five categories of mental-physical multimorbidity were constructed according to the number of non-communicable diseases and the existence of depressive symptoms，reported by participants. Multivariable linear regression models were applied to examine the association of physical and mental multimorbidity with cognitive decline. Results The mean cognitive function score was（54.7±19.9） among 9951 participants in China，（51.1±20.0） among 54802 participants in India，and （50.7±18.4） among 8446 participants in Indonesia. The cognitive score was significantly lower in those middle-aged and older adults with mental-physical multimorbidity in China（β=-6.99，95%CI=-8.26~-5.71），India（β=-2.76，95%CI=-3.41~-2.11）and Indonesia（β=-2.75，95%CI=-4.10~-1.41）than in those individuals without any non-communicable disease，after adjusting for socio-demographic and lifestyle behavioral covariates. Conclusion Cognitive decline is associated with mental-physical multimorbidity among middle-aged and older adults in China，India and Indonesia，particularly in females. Paying attention to and actively addressing mental health problems among patients with multimorbidity may reduce the risk of cognitive impairment and dementia in the elderly.

Key words: Multimorbidity, Middle aged, Aged, Mental-physical multimorbidity, Cognition performance, China, India, Indonesia

摘要： 背景 国内外研究证据显示慢性病共病与老年人群脑健康有密切联系。目前很少文献关注躯体和精神疾病同时对认知障碍的影响。目的 探索中国、印度和印度尼西亚中老年人群身心共病与认知功能下降的关联。方法本研究基于来自中国健康与养老追踪调查（CHARLS，2015 年）、印度纵向老龄化研究（LASI，2017—2018 年）和印度尼西亚家庭生活调查（IFLS，2014—2015 年）具有全国代表性的调查数据库，共纳入 73119 名受访者。从 3 个维度——时间定向、单词回忆和计算能力评估认知功能。根据报告的慢性非传染性疾病数量和存在抑郁症状情况构建了5 类身心共病情况。采用多元线性回归模型探究身心共病与认知功能下降的关系。结果 中国中老年受访者 9951 例，平均认知功能评分为（54.7±19.9）分；印度中老年受访者 54802 例，平均认知功能评分为（51.1±20.0）分；印度尼西亚中老年受访者 8446 例，平均认知功能评分为（50.7±18.4）分。多元线性回归分析结果显示，在调整了社会人口和生活行为方式等因素后，中国（β=-6.99，95%CI=-8.26~-5.71）、印度（β=-2.76，95%CI=-3.41~-2.11）、印度尼西亚（β=-2.75，95%CI=-4.10~-1.41）存在身心共病的中老年受访者认知功能低于无慢性病者（P<0.05）。结论 身心共病与中国、印度和印度尼西亚中老年人认知功能下降有关，且在女性中较明显。关注和积极应对共病患者的心理健康问题可能会减少老年人群发生认知障碍和失智症的风险。

关键词: 共病, 中年人, 老年人, 身心共病, 认知功能, 中国, 印度, 有印度尼西亚