I believe there is something to that. I used to say that I am like a bear hibernating in the winter (when depressed) and full of excess energy (manic) when the spring came. I still think there is something to that but now that I'm older and dealing with a disastrous past I feel even more depressed now then I did when I was younger.

Also, I have been tracking my mood swings for a long time and find that I can have depressive episodes in the summer months. These could be the results of months (or weeks) of being manic. So even if the changing seasons has something to do with changes in moods the rubber band effect from extreme depression and/or mania can happen which don't seem to have anything to do with the changing seasons at all.