Late Winter/Early Spring often brings on depression for me with boredom, being cold all the time, and just not having much energy. I tend to get depressed immediately after hypomania or mania, but I also get some break through depression at random times. Of course, life events make things worse, such as a losses, too much stress at work, or issues in relationships. Sometimes those changes make my moods more mixed though at first, then it turns into a depressive episode. Alcohol isn't good for me either.