正念干预改善抑郁个体执行功能及其神经机制

Mindfulness intervention improves executive functions of depressed individuals and their neural mechanism

抑郁症为危害大众身心健康的主要心理疾病.抑郁个体存在执行功能缺陷,而正念干预能有效改善抑郁个体的执行功能,缓解抑郁症状.根据抑郁认知理论、抑郁易感双重加工理论,本文认为抑郁个体的执行功能子成分工作记忆、认知灵活性、反应抑制能力存在缺陷,且保持与抑郁心境一致的认知加工偏差,导致增加负性自动化思维,削弱反思性加工;根据积极情绪构建扩展理论、正念的意义构建理论和监控接纳理论,认为正念干预能有效改善抑郁个体执行功能,减少执行功能缺陷导致的消极认知偏向.前额叶皮层、前扣带皮层、杏仁核、默认模式网络和额叶边缘系统的内在功能连接是正念干预抑郁个体执行功能缺陷的重要神经机制,影响抑郁个体对消极刺激的反应抑制、注意偏向和负性自动化思维.未来的研究应该着眼于深入探讨不同程度、不同类型的抑郁个体执行功能缺陷的差异性,阐明正念干预抑郁个体执行功能的内在机制,通过正念干预结合认知训练(例如工作记忆训练、记忆疗法或者认知控制训练)治疗抑郁.

By 2030,depression is expected to become a global economic burden due to its serious effect on people’s physical and mental health.According to Le Moult and Gotlib’s cognitive theory of depression,individuals with depression have executive function defects,which lead to negative cognitive processing bias and increased use of non-adaptive emotional regulation strategies such as rumination.According to Beevers’dual processing theory of cognitive vulnerability to depression,individuals with depression use more negative automatic processing and less reflective processing,which results in bad mood cycles.This review suggests that executive functions are closely related to reflective processing and that the improvement of executive functions provides depressed individuals with more cognitive resources for such processing.This is because the improvement of executive functions reduces the bias of negative cognitive processing and the negative automatic processing mentioned in the dual processing theory of cognitive vulnerability to depression.The decentralized mechanism of mindfulness can effectively improve executive functions,trigger reflective processing,particularly in depressed individuals,correct negative automatic thinking,and alleviate depressive symptoms.Depressive individuals have defects in working memory,cognitive flexibility,and response inhibition and maintain cognitive processing biases consistent with depressive mood.Therefore,executive function defects may be an important cognitive dispositional factor for individuals with depression.Mindfulness interventions can alleviate depressive symptoms and negative cognitive processing biases by improving executive functions.This review compared two studies published in Nature Reviews Neuroscience on the cognitive neural mechanisms of mindfulness and depression respectively,and then suggested that the intrinsic functional connectivity of the prefrontal cortex,anterior cingulate cortex,amygdala,default mode network,and frontal limbic system is an important neural mechanism for mindfulness intervention’s effect on the executive function defects of depressed individuals.Specifically,mindfulness intervention can activate the anterior cingulate gyrus in depressed individuals and enhance the functional connection between the prefrontal lobe and anterior cingulate gyrus,which is the neural mechanism of attentional control in mindfulness intervention.Improvements in attentional control are conducive to the inhibition of depressed individuals’responses to negative stimuli.Mindfulness interventions can effectively reduce the activation of the amygdala in depressed individuals and enhance the functional connection between the prefrontal cortex and amygdala,which is the neural mechanism for emotional regulation in depressed individuals.This can reduce attentional bias to negative stimuli and the feeling of negative emotions.Mindfulness interventions can also effectively reduce the activation level of the default mode network in depressed individuals and enhance the control of the central executive network,which is the neural mechanism that aids mindfulness in improving meta-awareness.Improvements in meta-awareness help depressed individuals reduce negative self-reference processing and rumination.Future research should first explore the interactions between the three components of executive functions in individuals with depression.The executive functions that are the most effective predictors of depression should also be explored.Next,the aspect of mindfulness intervention that has the largest effect on the executive functions of individuals with depression should be clarified,specifically,which executive functions of mindfulness intervention has the most obvious effect on depressed individuals—whether“Awareness”or“Acceptance”is the core component of the effectiveness of mindfulness interventions on individuals with depression.This should be proved by randomized dismantling trial.Finally,mindfulness intervention programs should be developed to improve the efficacy of depression treatment.“Acceptance”may be a key component of the effectiveness of mindfulness interventions for individuals with depression.Morita therapy can be integrated into the daily practice of mindfulness to improve individuals’acceptance of negative events.Cognitive impairment in individuals with subclinical depression is not very severe.Thus,cognitive training can first improve the cognitive functions of individuals with subclinical depression;then,mindfulness interventions that increase the acceptance can consolidate cognitive functions and relieve depressive symptoms.