Generalized linear model for total MADRS-S score and salivary melatonin levels at bedtime in patients (Model 1).

The relationship between low melatonin and high MADRS-S scores remains after including variables known as possible confounders (Model 2). First quartile denotes the quartile with lowest melatonin levels. Fourth quartile, with highest melatonin levels, is set as the reference. Season means summer vs. winter season.在校正了被认定为潜在混杂变量的变量后（模型2），低褪黑素（melatonin）与较高的蒙哥马利-阿斯伯格抑郁自评量表（MADRS-S）得分之间的关联依然成立。第一四分位数组指褪黑素水平最低的组别；第四四分位数组（褪黑素水平最高）被设为参照组。季节指代夏季与冬季的对比。