They are so preoccupied by self that they wont put any energy into their OLD life. They kill old self, they kill old life. All people from old life are burden for them. They try to live fantasy world in real world. Like ferry tale. That is pure projection of their own fantasy to reality. Their emotions are pointed only in that way. That is the reason why they look to us as dead, empty with shark eyes, living deaths, zombies. They live in other time / space then we do. It is quite interesting that their space / time is only their and all others from reality are only actors who are willing to play they twisted fantasy. Sure for that those actors have to be unusual people, lost in time - reality otherwise they wont participate. They use old personality as mask to defend own fantasy world. We just annoying them. The whole world for them is own head they are masters of scene, they play actually some kind of game. They CONTROL that world, if they don't like what is in it they move on next willing participant who wanna play their twisted game. They are aware that is something wrong with them.
When they showing overt depression in replay ? When are bored in their own fantasy world, alienator wanna out. So they usually have more actors in spare, so they go on another... And so on... Period when they haven't willing alienator on disposal they are overtly depressed to us.
And when REPLAY stop ? IMO stop when they become tired of playing own game, means become bored playing it, no getting any satisfaction from it.