抑郁个体对社会反馈的加工:研究现状及存在问题

Social Feedback Deficits in Individuals with Depression: The State of Art and Unsolved Problems

抑郁症伴随着严重的社会功能障碍。本文以"社会反馈"这一重要社会性信息为切入点,综述了抑郁症患者及抑郁倾向人群对社会反馈的体验、期待及情绪调节障碍的研究现状,发现抑郁个体对社会奖赏存在快感缺失,对社会排斥、社会拒绝等负性反馈表现出过敏化,对社会奖赏的期待降低,且可能存在情绪调节困难。目前此领域存在社会与非社会反馈神经机制的异同不清楚、异常脑区与社会反馈加工障碍的因果关系难以确定以及无法排除抑郁症患者和抑郁倾向人群存在不同社会反馈加工模式的可能性等问题。

Depression is associated with severe deficits of social function. Depressive symptoms are related to negative expectancy bias, social anhedonia, high sensitivity to, as well as impaired emotion regulation of, social exclusion and social rejection. This review focuses on social feedback, one of the most important social information, in individuals with depression （including clinical depression and subclinical depression）. We aim to investigate the anticipation, experience and emotion regulation processes of social feedback in individuals with depression. There are a number of paradigms measuring different aspects （anticipation, experience, or both） of social feedback processing. The most frequently used tasks are ＂cyberball＂ task, ＂social judgment＂ task, ＂chatroom＂ task, ＂social feedback＂ task, and ＂social incentive delay＂ task. Besides, other tasks are also commonly seen and used, such as social evaluative task, ＂character trait＂ task, ＂island getaway＂ task, and ＂the Montreal imaging stress＂ task. Firstly, researchers already have a deep understanding about the experiencing deficits of social feedback in individuals with depression. It is found that similar to nonsocial rewards （food or money）, individuals with depression also showed anhedonia to social rewards, i.e., positive social feedback, which may mainly be due to the hypoactivation of the nucleus accumbens （NAec） and hyperactivation of the medial prefrontal cortex （mPFC）. In contrast, individuals with depression exhibited abnormally increased sensitivity to negative social feedback （social exclusion and social rejection）, which is related to the overactivity of sgACC. Secondly, researchers are less concerned about the anticipation of social feedback in depression. However, the altered anticipatory processing is supported by some behavioral and neuroimaging findings. Specifically, individuals with depression showed impaired reward circuit （especially the ventral striatum） when anticipating monetary reward. In some behavioral findings, individuals with depression reported more negative expectation and less positive expectation about social interaction, which may suggest the dysfunction of this reward circuit in depressive people when they anticipate social feedback. Thirdly, although we found no direct evidence supporting the regulation of emotions evoked by social feedback in individuals with depression, they did show deficits in regulating basic emotions （happy and sad）. In studies on healthy individuals, rVLPFC seemed to be the crucial area of regulating social feedback, which may provide some valuable clues to studies on depression. The framework of this review is largely consistent with the ＂negative cognitive trait＂ in the unified model of depression. The unsolved problems in this research area are as follows： （1） The specificity of social feedback processing deficits in depression needs to be defined, because it is not clear that individuals with depression show the same or different deficits in processing social versus non-social feedback;（2） The causality/correlation between the observed brain dysfunction and the given behavioral deficits in social feedback processing in depression still puzzles us. However, some work may enlighten us. Using the non-invasive neurostimulation tools, such as rTMS, to excitatorily or inhibitorily stimulate the target brain area, researchers can then measure and compare behavioral and neuroimaging indexes between the real and the control groups and thus clarify this casual issue.（3） We cannot rule out the possibility that patients with clinical depression and individuals with subclinical depression have the different mode of social feedback processing deficits.