I just had that experience happen to me back in January. I started to get depressed and feel bad them suddenly it switch after a month (my depressions last a few months) and I turned severely manic and psychotic. I don't know what happened it was very strange. I think it was because my meds or what but it was a very hard time because I realized I have no control over this disorder. I am in the hands this disorder and even if I take meds there is a chance that it will be just like a flip of a switch. I'm scared to live my life because of this disorder.