Shrink Rap speculates on whether Darth Vader has a personality disorder:
Huh? BPD is not the first diagnosis I would come up with. I would've thought Narcissistic PD before BPD. Needs at least 5 of these :
has a grandiose sense of self-importance
is preoccupied with fantasies of unlimited success, power, brilliance, beauty, or ideal love
believes that he or she is "special" and unique and can only be understood by other special people
requires excessive admiration
strong sense of entitlement
takes advantage of others to achieve his or her own ends
is often envious or believes others are envious of him or her
arrogant affect.I think he had them all.
Narcissistic PD is the diagnosis I came up with 2 years ago in this classic post.