PPD, though more common than NPD, is often ignored or overlooked and I think can be (and often is) mistaken for Narcissistic Personality Disorder (NPD). The symptoms are remarkably similar and resemble the way a narcissist acts when in defense or attack mode. These are not very nice people. Someone with PPD acts like narcissist who is perpetually suffering narcissistic injury (must be fun!). They are combative, controlling, envious/jealous, unforgiving, and quick to project blame onto others. Also like narcissists, they are unlikely to think they have a problem so they rarely try to get help.
I wonder if PPD should actually be classified as a Cluster B personality disorder, since it involves a weak sense of self, hypersensitivity to real or imagined slights, and resultant abusiveness toward others and lack of insight/inability to accept blame. Other then a tendency to avoid social interaction, PPD doesn’t seem that much like the “odd/eccentric” (Cluster A) disorder it is currently classified as (it’s in the same subcategory with Schizoid and Schizotypal Personality Disorders, neither of which bear much resemblance to PPD).
I’ve known people who I thought were narcissists and who were definitely abusive, but their behavior actually more closely resembles PPD than NPD.
One thing that’s unique about people with PPD is that they are more likely than others to have a parent with schizophrenia.