A very high percentage of eminent writers, artists, inventors, explorers and other people which have changed the course of human history were considered either extremely moody, were manic depressive, or suffered from bouts of unipolar depression. There is not, however, any link between schizophrenia and such people. In the past, extreme episodes of mania were often confused with schizophrenia, leading some to believe there was a connection. One of the most common experiences ADDers online seem to share is that of mood swings generally lasting days or weeks. This is marked by periods of high intensity involving lots of ideas, plans, midnight email sessions, and lack of sleep, followed by a period of recovery consisting of fogginess and fatigue.
ADDers can also go into or come out of bad moods very quickly, even in a matter of a few minutes.
The mood swings typically last on the order of days and cycle very rapidly compared to manic depression. Hypomania is a state of mind which is mildly manic and marked by lots of ideas, enthusiasm and creativity. It is a fast mind, switching from thought to thought, and full of energy. It is believed that a significant percentage of great artwork was completed by artists while they were in a hypomanic state. The mania often starts out as hypomania, which is not too bad, but may increase in intensity until the person can talk non-stop for two hours and not complete a single sentence.