The term personality disorder is heard frequently in conversation and used in articles about the President. The term is typically used to convey disapproval about his flamboyant personality style. But there is a more precise and scientific use of the term.
Personality disorder refers to a limited number of conditions that are included in the two major diagnostic systems used throughout the world : The Diagnostic and Statistical Manual of Mental Disorders Version Five (DSM-V) and The International Classification of Disease Version 11 (ICD-11). To qualify for a personality disorder, two conditions must be met:
(1) The individual must display an enduring pattern (starting in childhood or adolescence and remaining relatively stable throughout the lifespan) of inner experience (distorted thoughts and difficult feelings) and troublesome behavior (impulse control problems and interpersonal relationships), that is pervasive across situations, and that deviates markedly from the individual’s culture; also,
(2) The pattern is maladaptive and pathological. It causes distress (to self or others), dysfunction (significant limitations in relationships, work or social activities) or disability.
It turns out that in the world of scientific investigation, there are a limited number of such extreme and maladaptive personality organizations, just ten in the DSM-V. One of those ten is called Antisocial Personality Disorder (ASPD). Within that (ASPD) diagnosis, there is a subset of individuals (approximately 25%) who suffer from a condition called psychopathic personality disorder (PPD).
Psychopathic personality disorder is considered to be the most virulent, dangerous and extreme form of Antisocial Personality Disorder. It is also the most researched and best understood of all the personality disorders.