http://www.washingtonpost.com/blogs/worldviews/wp/2013/11/07...
Japan has the lowest rate of diagnosed cases of depression of any country in the world (<2.5%). Of course, there could be other causes for this, and the accuracy of how well the diagnosed rate represents the actual rate is an open question. In particular, in east asian countries thre seems to be a cultural taboo against admitting mental illness and seeking treatment in order to get diagnosed in the first place. The fact that Japan has one of the highest suicide rates of any country in the world is an especially telling statistic that the diagnosed rate may not be telling us everything.