OBJECTIVE We applied the experimental therapeutics approach to test whether acute treatment outcomes for winter seasonal affective disorder (SAD) are mediated by a cognitive mechanism in cognitive-behavioral therapy (CBT-SAD) versus a chronobiologic mechanism in light therapy (LT). METHOD Currently depressed adults with major depression, recurrent with seasonal pattern (N = 177; 83.6% female, 92.1% non-Hispanic White, M age = 45.6) were randomized to 6 weeks of LT or group CBT-SAD. SAD symptoms were assessed weekly on the Structured Clinical Interview for the Hamilton Rating Scale for Depression-SAD Version. At pre-, mid-, and posttreatment, participants completed measures of general depressogenic cognitions (Dysfunctional Attitudes Scale; DAS); SAD-specific negative cognitions (Seasonal Beliefs Questionnaire; SBQ); chronotype (Morningness-Eveningness Questionnaire; MEQ); and depressive symptoms (Beck Depression Inventory-Second Edition). RESULTS Parallel-process growth models showed evidence for hypothesized mechanisms. For SAD-specific negative cognitions (SBQ), both symptom measures showed (1) an effect of treatment group on the slope of the mediator, with CBT-SAD demonstrating greater decreases, and (2) an effect of the slope of the mediator on the slope of the outcome. These effects held for the SBQ but not the broader measure of depressogenic cognitions (DAS). For the chronotype measure (MEQ), treatment assignment affected change, whereby LT was associated with reduced "eveningness," but this was unrelated to change in symptoms. CONCLUSIONS CBT-SAD promoted decreases in SAD-specific negative cognitions, and these changes were related to decreases in symptoms. Consistent with the theory that LT corrects misaligned circadian rhythms, LT reduced eveningness, but this did not correspond to symptom improvement. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

中文翻译：

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应用实验疗法来检查认知和时间顺序脆弱性作为认知行为疗法和冬季抑郁症光疗法急性结果的中介。

目标我们应用实验性治疗方法来测试冬季季节性情感障碍 (SAD) 的急性治疗结果是否由认知行为疗法 (CBT-SAD) 中的认知机制与光疗法 (LT) 中的时间生物学机制介导。方法 目前患有严重抑郁症、季节性复发的抑郁成人（N = 177；83.6% 女性，92.1% 非西班牙裔白人，M 年龄 = 45.6）被随机分配到 6 周的 LT 或 CBT-SAD 组。每周根据汉密尔顿抑郁量表-SAD 版本的结构化临床访谈评估 SAD 症状。在治疗前、治疗中和治疗后，参与者完成了一般抑郁性认知的测量（功能失调态度量表；DAS）；SAD 特定的负面认知（季节性信念问卷；SBQ）；计时型（早晚问卷；MEQ）；和抑郁症状（贝克抑郁量表-第二版）。结果 并行进程增长模型显示了假设机制的证据。对于 SAD 特定的负面认知 (SBQ)，两种症状测量都显示 (1) 治疗组对中介体斜率的影响，CBT-SAD 表现出更大的下降，以及 (2) 中介体斜率对结果的斜率。这些影响适用于 SBQ，但不适用于更广泛的抑郁认知 (DAS) 测量。对于计时型测量 (MEQ)，治疗分配影响变化，LT 与“晚间性”减少有关，但这与症状的变化无关。结论 CBT-SAD 促进了 SAD 特异性负面认知的减少，这些变化与症状的减轻有关。与 LT 纠正错位的昼夜节律的理论一致，LT 减少了夜晚，但这并不对应于症状的改善。（PsycInfo 数据库记录 (c) 2020 APA，保留所有权利）。