A "Personality Disorder" is a medical cop-out by a psychotropic medical industrial complex in its infancy testing a host of dangerous chemicals that interact with the human brain in trial and error experiments. Since medical science cannot measure our brain chemicals to know what we need to balance them, they just throw chemicals at patients until the patient lands on something they're actually willing to keep taking. Pumping peoples' heads full of the wrong chemical they don't need and making the relative shortages of the right chemical even worse.
Psychiatry takes a society-centric view instead of a patient-centric view, overlooking their own inability and culpability to treat mental illness effectively and dumping the burden on the sick person instead. It becomes the patient's fault. They have a personal problem; a "personality disorder" because they're bad for society, at least today's society. 20,000 years ago a manic episode would have gotten the men out of the cave to hunt the wooly mammoth when the women and children and the rest of the tribe was starving to death. That sleepless 24-hour high could mean the difference between life and death. But in the modern rat race of alarm clocks, deadlines, gadgets and ADHD, it's the obedient caffeine drinkers with the Protestant work ethic who have the personality order. Not the manics, neurotics or schizos.