抑郁倾向人群工作记忆偏向矫正的干预效果及其神经机制研究

According to the cognitive model of depression, bias and prolonged processing of mood-congruent negative information has a primary role in the development and maintenance of depression, this cognitive bias may increase vulnerability for the onset of disorders and should be considered in early intervention and prevention efforts. The disability to update negative information in working memory (WM) and resist intrusion from negative materials has been identified recently both in patients with depression and dysphoria and was defined as WM bias. WM is involved in the maintenance and manipulation of information that related to the current tasks, which is crucial to remove negative, no-longer relevant contents form WM and replace it with new, positive contents. Dysfunction of prefrontal-subcortical circuitry was suggested to be the underlying neural mechanism of WM bias. .The present study was aimed to investigate the behavioral and neural effects of WM bias modification intervention in reducing depressive symptoms of dysphoria. Firstly, the emotional valance n-back task, a WM bias measure, was validated in dysphoria, then behavioral and neuroimaging studies were conducted to investigate the effect of emotional dual n-back training on reducing depressive symptoms of dysphoria and whether this effects was mediated by training gains on WM bias. The present study could facilitate the understanding of cognitive and neural mechanism of cognitive bias modification intervention. More importantly, the current study has great implications for the understanding of cognitive vulnerability of depression and for future treatment approaches, and could provide the behavioral and neural basis for further understanding of neuroplasticity in depression and other mental disorders.

抑郁的认知理论认为，对负性信息的认知偏向是抑郁症状产生、持续和发展的重要原因之一。临床抑郁症患者与抑郁倾向人群在抑制工作记忆内负性信息上存在困难，更容易受到负性信息的干扰，从而表现出工作记忆偏向。工作记忆偏向是抑郁症认知易感性的核心表现形式，与前额叶-皮层下神经环路的功能异常有关。对工作记忆偏向干预的效果及其可行性的探讨，可为现有认知偏向矫正训练的作用机制提供理论佐证，并为抑郁症的早期预防和干预提供理论依据，既具有学术价值又具有一定的临床意义。本项目在申请人及前人研究的基础上，围绕工作记忆偏向这一研究问题，首先发展并验证了工作记忆偏向测量指标的有效性，进而将情绪工作记忆训练应用于工作记忆偏向矫正，并采用行为学和脑影像指标深入考察该训练方案在改善抑郁倾向人群抑郁症状上的效果及其可行性。本项目的开展有助于加深对工作记忆偏向作用机制及其可塑性的理解，有望对抑郁的认知理论加以修正和完善。

认知功能的改变不仅是抑郁症的典型症状，还是抑郁发作的重要风险因素。以往研究主要关注抑郁症的注意偏向、解释偏向和记忆偏向，对工作记忆偏向的研究相对较少。本项目围绕工作记忆与临床精神疾病的关联主要取得了以下成果：（1）探讨了抑郁症患者在工作记忆两大核心功能上的功能缺损表现；（2）系统梳理了抑郁症工作记忆与情绪交互的行为表现与神经机制（3）关注亚临床抑郁群体在愉快体验加工上的动态变化特征是否存在异常 （4）尽管抑郁症和精神分裂症在临床上是两种不同的疾病，但他们在临床表现（如快感缺失）和核心功能缺损（如工作记忆）方面表现出跨诊断的相似性。采用核磁共振成像技术考察了精神分裂症患者的工作记忆缺损及其可塑性，研究结果发现，精神分裂症患者在工作记忆和愉快体验加工方面的缺损可通过工作记忆训练而得以改善。在本项目资助下，目前申请人以第一作者或通讯作者已发表SCI/SSCI论文4篇，中文核心期刊论文1篇，抑郁倾向人群工作记忆加工的特征及工作记忆干预效果的相关研究结果申请人正在进行投稿准备，也将陆续发表。本项目为探讨亚临床抑郁倾向人群情绪工作记忆加工的特点以及工作记忆偏向训练在该群体中的训练效果验证提供了可靠的行为和神经指标。在本项目的基础上，未来研究可深入探究工作记忆内情绪刺激加工的神经机制，继续就工作记忆偏向矫正干预的潜在机制及其临床应用价值进行探讨。