User blog comment:ImperiexSeed/Castiel's shifting of Sam's mental problems made no sense!/@comment-4003779-20120402012732/@comment-3481504-20120402023631

Yeah, I know, only transferred. Seems permanent to me, unless Cas can't take it anymore, thus giving it back.

Also, if Castiel could do it, so can Death. Death could've just transferred them to a dead person, problem solved.