Depression is the leading cause of disability in the world.
抑郁症在世界上是造成失能的主要原因。
In the United States, close to 10% of adults struggle with depression.
在美国近10%的成人为抑郁所苦。
But because it's a mental illness, it can be a lot harder to understand than, say, high cholesterol.
但由于它是心理上的疾病，所以它比像高胆固醇之类的疾病还要让人难以理解。
One major source of confusion is the difference between having depression and just feeling depressed.
一个主要令人困惑的是“抑郁症”和“只是感觉沮丧”的差别。
Almost everyone feels down from time to time.
每个人都有失落的时候。
Getting a bad grade, losing a job, having an argument, even a rainy day can bring on feelings of sadness.
成绩考差了、被炒魷鱼、发生争执，甚至是下雨天都可能使人忧伤。
Sometimes there's no trigger at all. It just pops up out of the blue.
有时根本没有什么诱因。沮丧就会凭空出现。
Then circumstances change, and those sad feelings disappear.
接着情境改变，而沮丧的心情也随之消散。
Clinical depression is different.
临床上的抑郁症是不同的。
It's a medical disorder, and it won't go away just because you want it to.
它是一种疾病，正因为你要它如此，所以挥之不去。
It lingers for at least two consecutive weeks, and significantly interferes with one's ability to work, play, or love.
它至少会持续两个星期，并严重地干扰一个人的工作能力、游玩意愿或情感生活。
Depression can have a lot of different symptoms:
抑郁症可以有很多不同的症狀：
a low mood, loss of interest in things you'd normally enjoy, changes in appetite,
心情低落、对平常喜爱的事物兴趣缺缺、胃口改变、
feeling worthless or excessively guilty, sleeping either too much or too little,
觉得无用或过度的罪恶感、睡太多或太少、
poor concentration, restlessness or slowness, loss of energy, or recurrent thoughts of suicide.
难以专注、躁动或迟钝、没有活力、或反覆兴起自杀念头。
If you have at least five of those symptoms, according to psychiatric guidelines, you qualify for a diagnosis of depression.
如果你有至少5项症状，根据精神科的准则你会被诊断为抑郁症。
And it's not just behavioral symptoms.
它不只是行为上的症状而已。
Depression has physical manifestations inside the brain.
抑郁症在脑部还会有实质的表征。
