Things like seasonal affective disorder or sad can cause low mood around this time of year too.

季节性情感障碍或悲伤等情况，也会导致每年这个时候情绪低落。

Seasonal affective disorder—depression that begins during the winter months and lifts during spring and summer.

季节性情绪障碍——抑郁症开始于冬季，在春季和夏季就消退。

Recent research further suggests that light hitting your skin, not just your eyes, can help to reverse seasonal affective disorder.

最近的研究进一步表明，光不仅照在眼前，还照在皮肤上，可以帮助逆转季节性情绪紊乱。

Exposure to natural light or a bright artificial lightsource has been shown to be as effective as medication in treating somepeople with seasonal affective disorder.

在自然光或者明亮的人造光源下受照射已被证实是一种有效的治疗季节性情感抑郁症方法。

However, this was also the case with seasonal affective disorder and postpartum depression, which are now formally recognized in the Diagnostic and Statistical Manual of Mental Disorders.

季节性情感障碍和产后抑郁症曾经也面临过同样的情况，但是，现在它们已经被正式收录到《精神病诊断与统计手册》中了。