Can you have bipolar disorder (manic depression), then gradually become more and more depressed, until it just becomes unipolar (depression)?

That is not quite: How it works. A person with bipolar disorder has periods of markedly ^ energy, ^ impulsivity, elated or irritable mood as well as separate periods of low mood & energy. (a mixed state is also possible).However, I have seen bipolar individuals who over the years, developed one long, chronic depressive episode. Their manic or hypomanic episodes can sort of die out over time. But it is still >>.