What's the difference between dysthymia and major depressive disorder?

Intensity and durati: Dysthymic folk have at least two years of depressed mood most of the day, more days than not and require fewer additional symptoms for diagnosis. Depression is two weeks or more of at least five major symptoms (dysthymia two) with depressed mood or loss of pleasure as one, and cause a significant change in functioning from baseline.

Type of depression: Dysthymia, is a chronic type of depression that doesn't waver all that much in terms of intensity, as opposed to major depression which wavers widely in intensity. Metaphorically speaking, those with dysthymia experience it as having to wear a coat made of lead, 24-7, with little variation. Those with major depression experience the depressive lows almost like waves.