Hi,
I just thought I post this, as when it happened to me it was really quite scary and it was only after googling that I found other people going through similar.
In short, I had breast pain, which was found to be related to my cycle, and the breast consultant I went to see recommended high dose evening primrose oil. I never really suffered from PMT, so I never really took them. I started off with a lower dose, then went up to a higher one, taking 3 pills per day.
I started to feel really anxious all the time and every little thing set me off crying or flipping out. We went on holiday (this was last summer) and instead of relaxing immediately as I normally do, I started to feel worse and worse. It culminated with me having a massive showdown - screaming fit at DH and my DD1 as they made a tiny joke - everyone was really worried about me, including myself, as I ended up in a tiny room crying for hours for no reason whatsoever.
DH and I sat that night trying to work out what the hell was going on with me and it suddenly dawned on us - evening primrose tablets. I chucked them all in the bin and stopped taking them and after only a day I felt like a huge blanket of doom had lifted off my head. I later discovered on various forums that it can seriously affect your nervous system.
So I just wanted to warn everyone who starts to take these for the first time to monitor how they feel. Even if this only helps one person I will be glad that they don't have to go what I went through that time! I thought I was going mad.