And that's actually a key point and aspect of the diagnosis, what is colloquially called the "psychic vampire" phenomenon.
A metaphor is that the sufferer feels, shall we say, "lacking" or "invalid".
(This is not a spiritual phenomenon. One can be psychologically adequate and still realize how profound the need for Christ is.)
The things lacked are things like affirmation of existence, sense of power, sense of importance, worth, etc.
At least in an aspect I've seen here, the sufferer himself cannot "contain" himself, but also doesn't get the affirmation he needs if he does contain himself. The principle is: If you make a big enough mess, Mommy and Daddy will certainly have to clean up AND pay attention to you.
The more the sufferer can sucker anyone into an exchange which can then be drawn out by all manner of devices, the happier and more secure the sufferer of S-E feels. And the more frustrated or angry the sufferer's target gets, the more powerful the sufferer feels. " I can MAKE Mommy and Daddy pay attention to me!"
This is just a metaphor, but it works pretty well, both in terms of diagnosis and of directing response.
Fascinating theory.
Seriously problematic application; but, nevertheless, an interesting theory.
BTW, I am truly honored to have provided so many hours of contemplation.