I have been on Yaz for about a year now, and during the last couple of months I have been experiencing HORRIBLE mood swings and absolutely NO sex drive whatsoever. When I first started taking it, the first night I had the worst stomach cramps I have ever experienced in my entire life. I was tired all the time and really irritable. I have just decided to change pills because Yaz has made me depressed, and EXTREMELY moody. My boyfriend has suggested on numerous occasions that I am manic depressive because I'm so up and down all the time... the littlest things set me off into a fit of rage =( Ugh!