Mental- and physical-health conditions co-occur at a rate much higher than chance. Of patients who have a mental-health condition, more than half also have a physical disease, and these cases are associated with increased human suffering and societal cost. Comorbidity research to date has focused on co-occurring mental- and physical-health disorders separately, and relatively little research has examined the co-occurrence of mental- and physical-health dysfunction. In addition, even less is known about why mental- and physical-health dysfunction co-occurs or how to treat these cases. Thus, the aims of this article are to highlight the need for research at the intersection of physical- and mental-health dysfunction and to provide guidance on how to research cases of comorbidity. Toward these ends, we begin by presenting a selective overview of the possible role of biological processes in the co-occurrence of physical- and mental-health dysfunction using specific illustrative examples. Specifically, we outline how biological processes within the immune system and gastrointestinal system could underlie depression, irritable bowel syndrome, and their co-occurrence. We then advance and discuss a proposed research framework, including methodological and analytic guidance, that researchers could use when studying the phenomenon of co-occurring physical- and mental-health dysfunction.

中文翻译：

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研究同时发生的心理和身体健康功能障碍的概述和拟议的研究框架。

精神和身体健康状况同时发生的速度远远高于偶然性。在患有精神健康问题的患者中，一半以上还患有身体疾病，这些病例与人类痛苦和社会成本的增加有关。迄今为止，共病研究主要集中于同时发生的精神和身体健康障碍，而相对较少的研究探讨了精神和身体健康功能障碍的同时发生。此外，对于为什么精神和身体健康功能障碍同时发生或如何治疗这些病例，人们知之甚少。因此，本文的目的是强调在身体和心理健康功能障碍交叉点进行研究的必要性，并为如何研究共病病例提供指导。为了实现这些目标，我们首先使用具体的说明性示例，对生物过程在身心健康功能障碍同时发生中可能发挥的作用进行选择性概述。具体来说，我们概述了免疫系统和胃肠系统内的生物过程如何导致抑郁症、肠易激综合症及其同时发生。然后，我们提出并讨论一个拟议的研究框架，包括方法和分析指导，研究人员在研究同时发生的身心健康功能障碍现象时可以使用该框架。