It might very well be, or not be. Certainly hormonal issues affect a lot of people's moods, and I have read that people with bipolar disorder do sometimes have mood shifts related to hormonal issues. I have bipolar disorder and my answer is because sometimes I do and sometimes I don't. I do think that it is a very important topic for you to bring up with BOTH your psychiatrist and gynecologist. The latter should be more than familiar with hormonal issues that cause depression. I think they may choose certain birth control with this issue in mind.Not all hormonal birth control options work the same for all women. Also, perhaps your psychiatrist could work out a special plan for you around the time you get PMS. Even therapeutic plans could also help.