French psychiatrist Eric Bui at Toulouse University Hospital has diagnosed Anakin Skywalker and his evil alter-ego, Darth Vader, with borderline personality disorder. In an upcoming issue of Psychiatry Research, Bui and his colleagues argue that Star Wars' ominous heavy breather meets six of the condition's nine clinical criteria, including patterns of instability and impulsivity. Bui meant this as a teaching exercise, but some experts are taking it seriously. Who's the crazy one? (Watch some Star Wars fans act out Darth Vader's therapy session)

This explains a lot: Abandonment issues, violent dissociative episodes, and wild fluctuations between "idealizing and devaluing" Jedi mentors? Yup, says Tom Goldman in The Escapist, sounds like Bui has Anakin/Vader's number. But "even the researchers admit that the Emperor's influence" may have "inflamed" the patient's symptoms. If only Bui could have offer a "little psychotherapy" at that juncture.
"Darth Vader diagnosed with mental illness"

The diagnosis is flawed: Admittedly "Anakin shows borderline traits, but these do not persist into his adulthood" says UCLA child psychiatrist H. Eric Bender, to ABC News. As Vader, he's no longer struggling with his identity; he's resolved as a villain. Considering Vader's delusions of grandeur and tendency to power trip, says Bender, narcissistic personality disorder might be a better diagnosis for his later years.
"Darth Vader was mentally ill, researchers say"

Give Vader a break: Vader wasn't so much evil as under the evil control of the Emperor, says Emory psychiatrist Dr. Charles Raison, to CNN, and thus somewhat beyond the bounds of psychiatric diagnosis. Also worth noting: "Darth Vader laid down his life to save his son and kill the evil emperor," so maybe we just shouldn't be "type casting people who struggle with personality disturbances."
"What is Darth Vader's diagnosis?"