" Depression is a disorder of mood, so mysteriously painful and elusive in the way it becomes known to the self--to the mediating intellect--as to verge close to being beyond description. It thus remains nearly incomprehensible to those who have not experienced it in its extreme mode, although the gloom, " the blues" which people go through occasionally and associate with the general hassle of everyday existence are of such prevalence that they do give many individuals a hint of the illness in its catastrophic form. "