Mine has always come in waves in a sense. Normally the wave lengths have been very long. Like months between depressions. In the last year the wave length has gotten much shorter where there are weeks or days between them and they don't last very long. I attribute this very much to the med I am taking. It is working quite well but I will still get a period of a three day pretty bad depression that hits out of the blue. I was getting what I call a lot of rapid cycling up and down until I increased my dose and things balanced out. Normally this time of year I would be in a real deep one and I am not this year.