Olfaction and Emotion in Depression: Behavioral Electrodermal and ERP Measures

描述（由申请人提供）： 由于嗅觉、情绪和抑郁涉及皮层和皮层下（边缘系统）结构的重叠，嗅觉的研究可能对阐明抑郁患者与情绪反应异常和快感缺乏相关的神经生理功能障碍具有特别的希望。然而，对抑郁症患者嗅觉功能的研究相对较少，现有的研究受到缺乏神经生理学测量和方法学困难的限制。我们建议开发一个新的研究方向，其中多通道事件相关脑电位（ERPs）将被测量在抑郁症患者和健康对照愉快和不愉快的嗅觉刺激。这将利用现有的方法来精确控制嗅觉刺激（嗅觉计），也在电生理领域的新的数据分析技术。电流源密度（CSD;表面拉普拉斯算子）和时间主成分分析（PCA）相结合，以产生对应于有意义的嗅觉ERP分量的径向电流源的无参考测量。此外，高浓度和低浓度的愉快和不愉快的气味将被选择的基础上，心理生理测量，这将允许单独评估情绪效价和强度的影响。除了大脑ERP之外，还将记录通常伴随情绪处理的双侧皮电活动（EDA），以提供对嗅觉刺激的自主唤醒的交感神经介导的测量。经过初步的心理物理测量，我们建议测试30名未经药物治疗的抑郁症患者和30名健康对照组的性别，年龄，惯用手，吸烟史和种族/种族相匹配。ERP，EDA和行为措施将获得高浓度和低浓度的愉快和不愉快的气味在检测任务，这是为了尽量减少认知评价处理。还将获得气味强度/效价的单独判断，沿着用于评估气味检测阈值和气味识别的标准行为测试。以访谈者为基础的精神病理学自我评定将被用来检查患者的ERP和行为嗅觉缺陷与快感缺乏和其他抑郁症状的关系。快感缺乏是重性抑郁症的一个主要诊断特征。对其神经生理学基础的进一步了解可能会导致诊断亚型的识别和用于预测治疗反应的新标志物的改进。对抑郁症患者嗅觉的研究应该为测量和理解情绪反应的异常提供一个新的窗口，例如抑郁症患者的快乐体验减少。这也可能导致诊断评估和治疗选择的新方法的发展。

DESCRIPTION (provided by applicant): Given the overlap of cortical and subcortical (limbic) structures involved in olfaction, emotion and depression, the study of olfaction may hold particular promise for elucidating neurophysiologic dysfunctions associated with abnormalities of emotional reactivity and anhedonia in depressed patients. There has, however, been relatively little study of olfactory function in depressed patients and existing studies have been limited by lack of neurophysiologic measures and methodological difficulties. We propose to develop a new direction of research, in which multichannel event-related brain potentials (ERPs) will be measured in depressed patients and healthy controls to pleasant and unpleasant olfactory stimuli. This will take advantage of existing methods for precise control of olfactory stimuli (olfactometer) and also new data analytic techniques in the electrophysiologic domain. Current source density (CSD; surface Laplacian) and temporal principal components analysis (PCA) are combined to yield reference-free measures of radial current sources corresponding to meaningful olfactory ERP components. Also, high and low concentrations of pleasant and unpleasant odors will be selected on the basis of psychophysiologic measurements, which will allow separate assessment of emotional valence and intensity effects. In addition to brain ERPs, bilateral electrodermal activity (EDA), which typically accompanies emotional processing, will be recorded to provide sympathetically- mediated measures of autonomic arousal to the olfactory stimuli. After preliminary psychophysical measurements, we propose to test 30 unmedicated depressed patients and 30 healthy controls matched for gender, age, handedness, smoking history, and ethnicity/race. ERP, EDA and behavioral measures will be obtained to high and low concentrations of pleasant and unpleasant odors during a detection task, which is designed to minimize cognitive-evaluative processing. Separate judgments of odor intensity/valence will also be obtained, along with standard behavioral tests for assessing odor detection thresholds and odor identification. Interviewer-based and self-ratings of psychopathology will be used to examine the relation of ERP and behavioral olfactory deficits in patients to anhedonia and other symptoms of depression. Anhedonia is a cardinal diagnostic feature of major depression. Increased understanding of its neurophysiologic basis could lead to improved identification of diagnostic subtypes and new markers for prediction of treatment response. The study of olfaction in depressed patients should provide a new window for measuring and understanding abnormalities of emotional reactivity, such as reduced experience of pleasure in depression. This could also lead to development of new methods for diagnostic assessment and treatment selection.