慢性疼痛与抑郁症具有高度共病性,但迄今尚无成熟理论能够阐释二者共病的神经心理机制。对慢性痛与抑郁的脑机制研究提示,慢性痛和抑郁常常涉及到相似的情绪脑区活动的异常改变;与此相对应的是,行为学研究发现,疼痛患者与抑郁患者在加工疼痛或抑郁相关信息时表现出了模式相似的认知情绪偏差（CAB）。近年来,越来越多证据趋于一致,指出慢性痛和抑郁共有的情绪通路异常变化可能导致了相似的信息加工异常,是二者共病的神经心理基础,而认知情绪偏差则在行为上反映了这种变化,并且很可能是共病发生、发展及维持的重要因素。

Comorbidity of chronic pain and depressive disorders are highly prevalent, yet no sound theory has been proposed to describe the underpinning neuropsychological mechanism. Brain imaging studies reveal that chronic pain and depressive disorders share similar emotional circuit abnormalities, which are in consistent with the fact that patients suffering from chronic pains or depression show similar cognitiveaffective bias（CAB） towards pain-related or depression-related information in behavioral measures. Recently, convergent evidence strongly suggests that these emotional circuit abnormalities, causing similar deficits in information processing, may underlie the neuropsychological processes of pain-depression comorbidity. Cognitive-affective biases, as a set of behavioral indicators reflecting these abnormalities, may play an important role in emersion, development and maintenance of pain-depression comorbidity.