An Integrated Chronobiological-Cognitive Approach to Seasonal Affective Disorder

描述（由申请人提供）：拟议的NRSA项目将是研究培训计划的一部分，以准备P.I.作为心理健康的时间生物学和心理学机制的临床研究者。这个NRSA项目将是第一个整合领先的时间生物学和认知行为SAD研究人员的理论和专业知识的研究，以测试季节性情感障碍（SAD）的综合模型。本研究将采用前瞻性、纵向设计，通过以下方式在罗汉的SAD综合认知行为模型测试中阐明SAD的病因学基础：（1）比较SAD患者和从未抑郁的匹配对照组在夏季和冬季的脆弱性，以及（2）测试时间生物学和认知脆弱性在预测患者冬季抑郁症严重程度方面的相对和综合贡献，对照为认知脆弱性选择的测量是对非季节性抑郁症的认知脆弱性的既定测量，其研究支持其与SAD的相关性：沉思反刍;认知反应性，以及罗汉模型中提出的SAD特异性季节性认知的测量。时间生物学脆弱性将被测量为相位角差（PAD）的季节性变化：每个参与者的昼夜节律相位（如由昏暗光褪黑激素开始标记的）和睡眠的平均中点（如由腕动记录仪记录的）之间的时间差。为了测试组间效应和冬季抑郁严重程度的纵向预测，根据DSM-IV-TR标准，当SAD患者相对无症状时，将在夏季完成一次所有测量，当SAD患者经历重度抑郁发作时，将在冬季完成一次所有测量。在纵向线性混合模型分析中，夏季认知测量和PAD的季节性变化将被用作冬季抑郁严重程度的统计预测因子。为了控制基线抑郁严重程度，将在夏季和冬季实验室访视时获得抑郁严重程度测量值，夏季测量值将作为控制变量输入分析。这些认知和时间生物学的预测将检查独特的和相互作用的影响冬季抑郁症的严重程度。作为SAD研究的主要学科的合作，这项研究代表了SAD复发的综合病因学模型的第一次测试。综合病因学模型对SAD的治疗具有临床意义。具体而言，结果可以告知是否有必要制定新的治疗策略，即针对这些脆弱性和/或利用治疗层次的新型干预策略，以减少SAD的年度复发。 公共卫生相关性：季节性情感障碍（SAD）的特点是每年在秋季和冬季复发的临床抑郁症;因此，SAD患者每年平均衰弱5个月。估计影响了美国5%的人口。S.成年人，超过1450万人，SAD是一个重要的公共卫生问题。这项研究的目的是澄清心理和时间生物学的危险因素，每年SAD复发的第一次测试中的SAD的综合病因学模型在一个前瞻性的纵向设计。结果将对未来SAD研究产生影响，桥接时间生物学和心理学学科，以及为改善SAD的评估，治疗和预防提供经验性努力。

DESCRIPTION (provided by applicant): The proposed NRSA project will be part of a research training plan to prepare the P.I. for a career as a clinical investigator of the chronobiological and psychological mechanisms of mental health. This NRSA project will be the first study to integrate theory and expertise from leading chronobiological and cognitive-behavioral SAD researchers to test an integrative model of seasonal affective disorder (SAD). This study will use a prospective, longitudinal design to clarify the etiological underpinnings of SAD in a test of Rohan's integrative cognitive-behavioral model of SAD by (1) comparing the vulnerabilities between SAD patients and never-depressed matched controls at summer and winter, and (2) testing the relative and combined contributions of the chronobiological and cognitive vulnerabilities in predicting winter depression severity in patients and controls. The measures selected for the cognitive vulnerability are established measures of cognitive vulnerability to Nonseasonal depression that have research to support their relevance to SAD: brooding rumination; cognitive reactivity, and a measure of the SAD- specific seasonal cognitions proposed in Rohan's model. The chronobiological vulnerability will be measured as seasonal change in Phase Angle Difference (PAD): the difference in timing between circadian phase (as marked by the Dim Light Melatonin Onset) and the averaged midpoint of sleep (as recorded by wrist actigraphy) for each participant. To test between-group effects and the longitudinal prediction of winter depression severity, all measures will be completed once in the summer when the SAD patients are relatively asymptomatic, and once in the winter when the SAD patients are experiencing a Major depressive Episode, per DSM-IV-TR criteria. The summer cognitive measures and a seasonal change in PAD will be utilized as statistical predictors of winter depression severity in a longitudinal linear mixed model analysis. To control for baseline depression severity, depression severity measures will be obtained at both the summer and winter laboratory visits, with the summer measure will be entered into the analysis as a control variable. These cognitive and chronobiological predictors will be examined for unique and interactive effects on winter depression severity. As a collaboration of the leading disciplines in SAD research, this study represents the first test of an integrative etiological model of SAD recurrence. An integrative etiological model holds clinical implications for the treatment of SAD. Specifically results may inform whether new treatment strategies, i.e. the development of novel intervention strategies targeting these vulnerabilities and/or utilization of a treatment hierarchy, are warranted to reduce annual SAD recurrence. PUBLIC HEALTH RELEVANCE: Seasonal affective disorder (SAD) is characterized by annual recurrence of clinical depression in the fall and winter months; individuals with SAD are thus debilitated for an average of 5 months per year. Affecting an estimated 5% of U. S. adults, over 14.5 million individuals, SAD is an important public health problem. The proposed study aims to clarify the psychological and chronobiological risk factors related to annual SAD recurrence in the first test of an integrative etiological model of SAD in a prospective longitudinal design. Results will have implications for future SAD research bridging the chronobiological and psychological disciplines, as well as informing empirical efforts for improved assessment, treatment, and prevention of SAD.