I get that too when I'm depressed...I attribute it to the lack of concentration; I'll be reading or watching tv or something and kind of drift off. It is really frustrating because I know when I'm depressed I should try not to just sleep all the time, so I try to find
something to do, but then I just can't stay focused on whatever it is I'm trying to do and end up wanting to go back to bed. Hang in there and I hope things look up soon!
__________________
From the movie The Hours: "If I were thinking clearly, Leonard, I would tell you that I wrestle alone in the dark, in the deep dark, and that only I can know. Only I can understand my condition. You live with the threat, you tell me you live with the threat of my extinction. Leonard, I live with it too."