As fall and winter come to some parts of the world, daylight hours grow shorter. This lack of light can cause seasonal depression. 

随着秋季和冬季的到来，世界上一些地区的白天时间变得越来越短。光照不足会导致季节性抑郁症。 

“It (is) a feeling of panic, fear, anxiety and dread all in one,” said Germaine Pataki. The 63-year-old woman living in Saskatoon, Saskatchewan, Canada, is among the millions of people estimated to have seasonal affective disorder, or SAD. 

“这是一种恐慌、恐惧、焦虑和恐惧的感觉，”杰梅因·帕塔基说。这位居住在加拿大萨斯喀彻温省萨斯卡通的 63 岁女性是估计患有季节性情感障碍 (SAD) 的数百万人之一。 

To deal with her condition, Pataki uses yoga, walking, and an antidepressant medication. She is also part of a Facebook group for people with SAD and helps others deal with the condition. Pataki said, “This gives me purpose.” 

为了应对自己的病情，帕塔基使用瑜伽、步行和抗抑郁药物。她还是 Facebook 社交情感障碍患者小组的成员，并帮助其他人应对这种情况。帕塔基说：“这给了我目标。” 

People with SAD usually have depression that begins in the fall and eases in the spring or summer. Changing the clocks back to standard time, which happens in autumn in the United States, can also cause SAD to start. 

患有季节性情感障碍的人通常会在秋季开始抑郁，并在春季或夏季缓解。将时钟改回标准时间（在美国发生在秋季）也可能导致 SAD 启动。

Medical experts say there is a milder form, called subsyndromal SAD. There is also summer seasonal depression but less is known about that. 

医学专家表示，还有一种较温和的形式，称为亚综合征型季节性情感障碍 (SAD)。还有夏季季节性抑郁症，但人们对此知之甚少。 

In 1984, a team led by Dr. Norman Rosenthal, then a researcher at the National Institutes of Health, first described SAD. He invented the term. 

1984年，由时任美国国立卫生研究院研究员的诺曼·罗森塔尔博士领导的研究小组首次描述了季节性情感障碍（SAD）。他发明了这个词。

Scientists are still learning the causes of seasonal affective disorder. They have found that specialized cells in our eyes turn the blue wavelength of the light into neural, or brain signals. These signals affect mood and wakefulness, or alertness. 

科学家们仍在研究季节性情感障碍的原因。他们发现我们眼睛中的特殊细胞将蓝色波长的光转化为神经或大脑信号。这些信号会影响情绪和清醒度或警觉性。 

Sunlight has a lot of blue light. So, when the cells sense this blue light, the alertness centers of our brains turn on. We feel more alert and possibly even happier. 

阳光中含有大量蓝光。因此，当细胞感受到这种蓝光时，我们大脑的警觉中枢就会开启。我们感到更加警觉，甚至可能更加快乐。 

Kathryn Roecklein is a researcher at the University of Pittsburgh. She tested people with and without SAD to see how their eyes reacted to blue light. As a group, people with SAD were less sensitive to blue light than others, especially during winter months. That suggests a cause for wintertime depression. 

凯瑟琳·罗克林 (Kathryn Roecklein) 是匹兹堡大学的研究员。她测试了患有和未患有悲伤症的人，看看他们的眼睛对蓝光有何反应。作为一个群体，患有季节性情感障碍的人对蓝光的敏感度低于其他人，尤其是在冬季。这表明冬季抑郁症的一个原因。 

“In the winter, when the light levels drop, that, combined with a lower sensitivity, might be too low for healthy functioning, leading to depression,” Roecklein said. 

“在冬天，当光照水平下降时，再加上敏感度较低，可能对健康功能来说太低，从而导致抑郁症，”罗克莱因说。 

Miriam Cherry is 50 years old and lives in New York state. She spent the summer planning how she would deal with her winter depression. “It’s like clockwork,” Cherry said. “The sunlight is low. The day ends at 4:45 , and suddenly my mood is horrible.” 

Miriam Cherry 50 岁，住在纽约州。她整个夏天都在计划如何应对冬季的抑郁症。“这就像发条一样，”切里说。“阳光很低。这一天在 4 点 45 分结束，突然我的心情很糟糕。”