You may want to refer to the sticky threads at the top of the forum, e.g. Bipolar 101, for more definitive answers. I can tell you that when I'm depressed, I feel hopeless, helpless, worthless, and uninterested in things that I enjoy in better times. I also tend to have suicidal ideation. When I'm hypomanic (less severe than full-blown mania) I'm chatty, bouncy, and very productive; unfortunately I often go straight on to mania, during which I'm not only hyperactive and hypersexual, but I get grandiose and paranoid, thinking I'm on some mission from God but people are trying to stop me. I also become unreasonably angry and irritable, and I've actually been sent home from work because I was romping up and down the halls alternately singing and proclaiming my rage to all the facility.

Those are only part of the picture. I'm sure others will be along to share their stories too.