The days get shorter, the air gets colder, and we all get stuck inside a lot more. Who wouldn't find winter just a little bit depressing?
白天愈來愈短也愈來愈冷，我們也更常躲在室內。有誰不會覺得冬天令人有點沮喪呢？
Many of us may get a bit blue in the winter, living in the dark, unable to enjoy the weather very much. But for some people, these blues can become something quite serious. Seasonal Affective Disorder (appropriately shortened to “SAD”) is the name for a mood disorder that causes normally mentally healthy people to become seriously depressed in the winter.
許多人或許會在冬天變得有點憂鬱，他們生活在黑暗中，無法好好享受天氣。但對某些人來說，這種憂鬱可能會變得很嚴重。季節性情緒失調（簡稱為SAD）是一種情緒上的失調，通常會使精神健康的人在冬天變得嚴重憂鬱。
People with SAD may start to have trouble waking up on winter mornings. Some of them may even feel sick in the mornings. They may lose their energy, especially in the afternoon, and they may move slowly and sluggishly. Unlike with other depressions, people with SAD feel hungrier than usual and desire carbohydrates. One sign of SAD, in fact, is gaining significant weight in the winter. SAD sufferers may often become irritable and stop wanting to see friends and family.
Doctors don't know exactly why people get SAD, but two things are probably important causes: sunlight and hormones in the body. Sunlight is important in several ways. It tells us when to sleep and when to wake up. This may explain the problems SAD sufferers have waking up. Sunlight can also affect how much serotonin our brains produce. Serotonin influences happiness. The lack of sunlight may also cause people to make more melanin, a hormone which makes us slow and sleepy.
