Information-Processing Biases in Depression

描述(申请人提供)：抑郁症是所有精神疾病中最普遍的疾病之一，占所有精神疾病经济成本的20%以上。一个重要的公共卫生优先事项是开发方法，以确定既增加个人抑郁易感性，又阻碍从这种疾病中恢复的因素。为了追求这一目标，我们一直在进行研究，通过检查对情绪刺激的生物反应模式来拓宽抑郁症认知模型的焦点。根据我们早期的研究和现有的模型，我们预测被诊断为严重抑郁障碍(MDD)的个体将表现出对负面刺激的自主神经唤醒和神经激活增加。但我们的发现表明情况并非如此；在功能磁共振成像和心理生理学研究中，MDD患者对积极和消极刺激的反应都比非抑郁对照组表现出更少的激活和唤醒。此外，更大的活性和反应性预测在接下来的一年中功能改善，与MDD的严重程度无关。在将这些结果与我们早期的发现进行协调和整合的过程中，我们正在拓宽和提炼抑郁症的认知理论，以包括情感计时学、对奖励刺激的敏感性和生物功能，不仅是为了描述抑郁个体的功能，也是为了预测从这种障碍中恢复。本申请中提出的研究旨在测试更全面的抑郁症公式，并系统地排除对我们所获得的结果的重要替代解释。根据我们最初的发现，我们假设，当面对情感上有效的刺激时，抑郁的人会立即注意到它；如果刺激持续存在，他们就会停止处理并脱离它。此外，那些能够持续受到情绪刺激的抑郁症患者可能最快从抑郁中恢复过来。这项拟议项目的总体目标是促进我们对MDD对情绪刺激的认知和神经生物学反应的理解。我们特别感兴趣的是刺激类型(即情感效价)、刺激持续时间(即情感计时法)以及特定患者特征(例如快感缺乏、共病的Axis-II人格障碍)对抑郁症患者情绪功能的潜在影响。我们建议检测抑郁和非抑郁参与者对情绪刺激的反应中的信息处理偏差和奖赏反应，以及伴随的神经激活和心理生理唤醒。来自测试这些配方的拟议研究的发现将对抑郁症的综合心理生物学理论的发展做出重要贡献。

DESCRIPTION (provided by applicant): Depression is among the most prevalent of all psychiatric disorders, accounting for over 20% of economic costs for all mental illness. An important public health priority is the development of methods for identifying factors that both increase individuals' vulnerability to depression and hinder recovery from this disorder. Pursuing this objective, we have been conducting research that broadens the focus of cognitive models of depression by examining patterns of biological reactivity to emotional stimuli. Extrapolating from our earlier studies and from existing models, we predicted that individuals diagnosed with Major Depressive Disorder (MDD) would exhibit increased autonomic arousal and neural activation in response to negative stimuli. But our findings indicated otherwise; in both fMRI and psychophysiological studies, MDD individuals demonstrated less activation and arousal in response to both positive and negative stimuli than did nondepressed controls. Moreover, greater activation and reactivity predicted improved functioning over the following year, independent of MDD severity. In reconciling and integrating these results with our earlier findings, we are broadening and refining cognitive theories of depression to include a consideration of affective chronometry, sensitivity to reward stimuli, and biological functioning, not only to describe the functioning of depressed individuals, but also to predict recovery from this disorder. The studies proposed in this application are designed to test a more comprehensive formulation of depression and to systematically rule out important alternative explanations for our obtained results. Based on our initial findings, we posit that when confronted with an emotionally-valenced stimulus, depressed persons immediately attend to it; if the stimulus persists, they shut down their processing and disengage from it. Moreover, those depressed individuals who are able to stay engaged with emotional stimuli are likely to recover from depression most quickly. The overall objective of this proposed project is to advance our understanding of the cognitive and neurobiological responses in MDD to emotional stimuli. We are particularly interested in the effects of stimulus type (i.e., affective valence), stimulus duration (i.e., affective chronometry), and the potential effects of specific patient characteristics (e.g., anhedonia, comorbid Axis-II personality disorder) on emotional functioning in depression. We propose to examine information-processing biases and reward responsivity, as well as concomitant neural activation and psychophysiological arousal, in response to emotional stimuli in depressed and nondepressed participants. Findings from the proposed studies testing these formulations will contribute importantly to the development of an integrative psychobiological theory of depression.