The DSM-5 says that roughly 15% of people meet the criteria for a personality disorder. And most of them are never diagnosed. Now you’re not a psychiatrist and neither am I, so we shouldn’t run around diagnosing people…
But we can learn enough to recognize if someone is a “high-conflict person”, reasonably give a diagnosis of “no good for moi” and steer clear of them.
More here – Barking Up The Wrong Tree