I too had a diagnosis of bipolar and have come to doubt it. I was diagnosed in 1999 and I think that was because of some depression and some hypomania. Since changing my GP, I have never once brought up the diagnosis and my GP thinks that its just low mood. I kind of agree with him.

I think bipolar is overdiagnosed in a lot of cases. I have a friend who was diagnosed as having bipolar and even spent time on admission only to find out that she had Grave's Disease.