Bipolar disorder meaning of dreams

I would just like to say that i have this dream every time my brother becomes ill (he suffers with bi-polar)... I am with my brother, and he has got a silver key from somewhere, i ask him where he got the key from but he just tells me to "follow him" So i do, and we end up at a block of flats, quite old looking, grey and only about 3 storys high. We go into the flats, upto the top floor, and come to a dark brown door, i ask him whos' flat this is and he says he doesnt know, but it will provide shelter for us. So he unlocks the door, and we go inside. The door leads straight into the main room. In this room is an old looking tv, a few empty book cases, a dirty green carpet, a mirror, and a small round brown table with nothing on it. Suddenly (and i dont know how) but i realise that the old lady who used to live here had recently died. Upon saying this to my brother, a smart looking lady walks in, she is wearing a black skirt suit. She doesnt seem phased by the fact that we are in there, but instead asks us if we are the old ladys gran children, i say no she is our aunty. The lady then says, that we are entitled to the inheritance that she left. Me and my brother are excited, and the lady leaves. Me and my brother then leave the room, lock the door, and make our way back down to the ground floor. Waiting for us on the bottom of the stairs, are a group of kids younger than us. They start saying mean things (of which exactly i can never seem to remember) i turn around to brother, and he is gone. Then i wake up.

My brother suffers with Bipolar disorder, and sometimes gets ill and goes manic. I always have this dream at this time.Please help me understand this, as i have been trying to interpret it my self for ages, but with no luck.