Neurobiology Research Unit, Rigshospitalet and Center for Integrated Molecular Brain Imaging, Section 6931, Blegdamsvej 9, 2100 Copenhagen, Denmark.
Neurobiology Research Unit, Rigshospitalet and Center for Integrated Molecular Brain Imaging, Section 6931, Blegdamsvej 9, 2100 Copenhagen, Denmark; Department of Biostatistics, University of Copenhagen, Øster Farimagsgade 5, 1014 Copenhagen, Denmark.
J Affect Disord. 2018 Mar 15;229:288-295. doi: 10.1016/j.jad.2017.12.097. Epub 2018 Jan 3.
Seasonal affective disorder (SAD) is characterized by seasonally recurring depression. Heightened amygdala activation to aversive stimuli is associated with major depressive disorder but its relation to SAD is unclear. We evaluated seasonal variation in amygdala activation in SAD and healthy controls (HC) using a longitudinal design targeting the asymptomatic/symptomatic phases of SAD. We hypothesized increased amygdala activation to aversive stimuli in the winter in SAD individuals (season-by-group interaction).
Seventeen SAD individuals and 15 HCs completed an implicit emotional faces BOLD-fMRI paradigm during summer and winter. We computed amygdala activation (SPM5) to an aversive contrast (angry & fearful minus neutral) and angry, fearful and neutral faces, separately. Season-by-group and main effects were evaluated using Generalized Least Squares. In SAD individuals, we correlated change in symptom severity, assessed with The Hamilton Rating Scale for Depression - Seasonal Affective Disorder version (SIGH-SAD), with change in amygdala activation.
We found no season-by-group, season or group effect on our aversive contrast. Independent of season, SAD individuals showed significantly lower amygdala activation to all faces compared to healthy controls, with no evidence for a season-by-group interaction. Seasonal change in amygdala activation was unrelated to change in SIGH-SAD.
Small sample size, lack of positive valence stimuli.
Amygdala activation to aversive faces is not increased in symptomatic SAD individuals. Instead, we observed decreased amygdala activation across faces, independent of season. Our findings suggest that amygdala activation to angry, fearful and neutral faces is altered in SAD individuals, independent of the presence of depressive symptoms.
季节性情感障碍（SAD）的特征是季节性反复发作的抑郁。杏仁核对厌恶刺激的激活增强与重度抑郁症有关，但与 SAD 的关系尚不清楚。我们使用针对 SAD 无症状/症状期的纵向设计，评估了 SAD 患者和健康对照组（HC）的杏仁核激活的季节性变化。我们假设 SAD 个体在冬季对厌恶刺激的杏仁核激活增加（季节-组交互作用）。
17 名 SAD 患者和 15 名 HC 在夏季和冬季完成了一个内隐情绪面孔 BOLD-fMRI 范式。我们分别计算了杏仁核对厌恶对比（愤怒和恐惧减去中性）和愤怒、恐惧和中性面孔的激活（SPM5）。使用广义最小二乘法评估了季节-组和主效应。在 SAD 个体中，我们用 Hamilton 抑郁评定量表 - 季节性情感障碍版本（SIGH-SAD）评估的症状严重程度变化与杏仁核激活的变化进行了相关性分析。
我们没有发现厌恶对比的季节-组、季节或组效应。无论季节如何，SAD 个体的杏仁核对所有面孔的激活都明显低于健康对照组，没有证据表明存在季节-组交互作用。杏仁核激活的季节性变化与 SIGH-SAD 的变化无关。
样本量小，缺乏正性效价刺激。
在有症状的 SAD 个体中，对厌恶面孔的杏仁核激活并没有增加。相反，我们观察到无论季节如何，杏仁核对所有面孔的激活都降低了。我们的研究结果表明，SAD 个体对愤怒、恐惧和中性面孔的杏仁核激活发生了改变，与抑郁症状的存在无关。
