This graphic I made shows that BPD and NPD are really the same disorder. Both have their roots in childhood trauma and fear of abandonment, even though the symptoms may not be evident until later childhood or adolescence. The primary difference is the outer layer–the narcissist develops a nearly impermeable and rigid false self or mask (usually of grandiosity, but sometimes can present as do-gooder or even a victim). This mask remains stable unless narcissistic supply is removed, which causes it to atrophy, revealing the rage, fear, and hurt beneath that.
The borderline develops a highly permeable, chameleon-like outer layer. In the diagram, it looks like a flower. This outer layer of “petals” is analogous to the false self, but is not rigid and not even always present. It is easily penetrated and does not require narcissistic fuel from others to keep it intact. It changes and morphs its shape and form like a Lava lamp. Since it’s so easily broken through and is so changeable, Borderlines seem to be “crazier” and seem to have more intense mood swings than narcissists. They are also skilled in adapting to different situations and people in a chameleon-like way: this usually manifests as codependency. Sometimes they don’t seem to have minds of their own and take on the behaviors and belief systems of whoever they happen to be with. Borderlines seem more emotionally unstable than narcissists because the second layer of rage/hurt/fear is often on the surface, causing the Borderline to act out in frequent rages, panic attacks or crying jags.
Beneath these outer layers, NPD and BPD have the same structure: a layer of rage, hurt and fear when they are triggered, hiding the emptiness and grief under that (which is what both–especially the NPD–are so afraid of confronting and take such desperate measures to avoid feeling). When this part of the personality structure is finally reached, the NPD/BPD feels as if they don’t exist and that is excruciating for them. NPDs in therapy may quit at this point. Hidden deep within the “emptiness” (which really isn’t empty at all) is the diminished and damaged true self (inner child).
The goal in therapy is to break through all those outer layers and finally reach the true self, then give him or her the nurturing and validation they should have received in the hopes that he or she can become a whole person. It can take a very long time for this to happen, if it ever happens at all.
Borderlines, although they might seem crazier than narcissists, are more easily cured because the permeable chameleon-like outer layer is so much more easily broken through. In contrast, the NPD false self can take months or years to even crack. It’s a thick and stable structure, not given to weakening easily, but even the strongest concrete building has hairline cracks somewhere in its structure. A tornado can reduce the strongest building to rubble.
The key to breaking a narcissist is to find those cracks and weaken the false self. This is usually done by removing narcissistic supply, which serves as a psychological tornado to the narcissistic defensive structure. Sometimes this has already happened; and in this more vulnerable state, with the false self temporarily disabled, a narcissist is more likely to enter therapy. Unfortunately the narcissistic defense mechanism is so ingrained they will soon find a way to get supply again and rebuild the false self. The therapist must work to permanently disable it but the narcissist must also be willing for this to happen.
In a low spectrum narcissist, the false self may be rather weak or thin to begin with, and for them, a cure may be more likely or happen sooner. In low spectrum narcissists, the false self is more like a cheaply constructed trailer than a stone castle. It will only take a weak tornado to smash it to smithereens.
When an NPD’s mask begins to fall away, they will begin to act a lot more like a Borderline–raging, dissociating, experiencing crying jags, and showing their underlying inability to regulate overwhelming emotions. At this point the treatment for NPD should be much the same as for BPD–empathically penetrating the “void” to reach and begin to nurture the diminished real self.
How a child develops BPD or NPD.
These disorders begin when a young child or toddler is hurt or rejected by their parents, especially the mother. This hurt may not even be intentional–sometimes the illness, death, or absence of a non-disordered parent can set things into motion, because the child can’t discern the difference between deliberate abuse or neglect and something that cannot be helped. Many, if not most, children who live in orphanages or are moved from foster home to foster home develop some form of Cluster B disorder.
Because a toddler or very young child has not yet completely separated their sense of self from their parents’, when they don’t receive the mirroring and unconditional acceptance they need, they feel as if they’ve been annihilated, and that feeling of annihilation becomes the black void that now surrounds the hurt or abused child.
But because the void is too painful and frightening to cope with, something else must cover that over too, and also protect and hide the inner child. So the defensive emotions (anger, paranoia, fear, and rage) develop over the void because even though they feel unpleasant, they’re still better than the horrible feeling of having been annihilated, and they also protect the inner child from ever being hurt again.
And over that, for a narcissist, to attract people who could provide the attention and validation they never got as children, they develop a fake self, which is usually “nice” but is only a mask so it isn’t real. If they feel that the mask is under threat of exposure, they fight tooth and nail to retain the image they want the world to see.
For the borderline, instead of developing a false self to cover the rage and other defensive emotions, they learn to adapt depending on the situation or the people, and that is why they so often become codependent. Also, because they are closer to the void than the narcissist is, they tend to have dissociative episodes and may engage in self destructive actions like cutting to make them feel like they exist. Or they may engage in other risky behaviors or taking drugs or drinking too much in an effort to self-medicate.
DISCLAIMER: I am not a mental health professional, but I’m well read on these disorders and these are from my observations and opinions.