Trait and State Frontal Brain Asymmetry in Depression

描述（由申请人提供）：不对称的大脑额叶活动有望成为抑郁症风险的标志。超过40项研究表明，静息额叶脑电图（EEG）不对称可能是一种以情绪消极和行为退缩模式应对情绪情境的特质性素质的指标。此外，静息额叶脑电图的不对称性区分了抑郁个体——那些目前有症状的和处于缓解期的——和从未抑郁过的个体。这些发现表明，额叶脑电图不对称不仅仅是抑郁症发作的相关因素，还可能成为抑郁症发展的一个危险标志。这样的标记可能具有预后和病因学价值，但叠加在特征样稳定性上的是波动，波动随评估场合或实验操纵的情绪而变化。额叶脑电图不对称的稳定性估计在。60，这表明特质因素是重要的，但不同评估的差异可能会限制不对称额叶脑活动作为抑郁症特质风险指标的效用。这些因素可能是本文献中少数不一致发现的基础。本研究通过评估额叶脑电图不对称的三个不同变异性来源，代表了对额叶脑电图不对称作为抑郁症潜在风险指标的程序化研究的必要步骤：1)在多个评估中保持稳定的特征一致性；2)从一个评估到下一个评估的特定场合波动；3)单个评估中与状态相关的变化。在四次访问中，将评估抑郁和非抑郁受试者的特质静息和状态操纵额叶脑电图不对称。这个设计将使我们能够解决几个具体的目标，包括：1)评估特质、场合和状态方差在额叶脑电图不对称中的相对贡献；2)评估额叶脑电图不对称是否具有可作为重度抑郁障碍风险标志的特征；3)评估广泛使用的选择性5 -羟色胺再摄取抑制剂对额叶脑电图不对称的急性影响，因为药物作用在很大程度上尚未被探索。次要目的是解决方法和治疗相关的问题，以及评估性别和月经周期的影响，这些影响可能会缓和额叶脑电图不对称与抑郁症之间的关系。

DESCRIPTION (provided by applicant): Asymmetrical frontal brain activity holds promise as a marker of risk for depression. Over 40 studies suggest that resting frontal electroencephalographic (EEG) asymmetry may serve as an indicator of a trait-like diathesis to respond to emotional situations with a pattern of emotional negativity and behavioral withdrawal. Moreover, resting frontal EEG asymmetry distinguishes depressed individuals -- those currently symptomatic as well those as in remission -- from never-depressed individuals. These findings suggest that frontal EEG asymmetry is more than a correlate of a depressive episode, potentially serving as a liability marker for the development of depression. Such a marker could have prognostic and etiological value, but superimposed on the trait-like stability are fluctuations that vary as a function of occasion of assessment or experimentally manipulated emotion. Estimates of the stability of frontal EEG asymmetry are in the range of.60, suggesting that trait factors are substantial, but that variation across assessments may limit the utility of asymmetrical frontal brain activity as a trait-like risk indicator for depression. Such factors may underlie the few inconsistent findings in this literature. The present proposal represents a necessary step in the programmatic investigation of frontal EEG asymmetry as a potential risk indicator for depression, by evaluating three distinct sources of variability in frontal EEG asymmetry: 1) Stable trait consistency across multiple assessments; 2) Occasion-specific fluctuations from one assessment to the next; and, 3) State-dependent changes within a single assessment. During four visits, trait resting as well as state manipulated frontal EEG asymmetry will be assessed in depressed and nondepressed subjects. This design will allow us to address several specific aims, including: 1) To assess the relative contributions of trait, occasion, and state variance in frontal EEG asymmetry; 2) To assess whether frontal EEG asymmetry has characteristics that suggest it may profitably serve as a marker of risk for major depressive disorder; and, 3) To assess the acute impact of a widely used selective serotonin reuptake inhibitor on frontal EEG asymmetry, as medication effects have been largely unexplored. Secondary aims address methodological and treatment-related questions, as well as assessing gender and menstrual cycle effects that may moderate the relationship between frontal EEG asymmetry and depression.