An article in LiveScience has Star Wars enthusiasts asking if anything in the galaxy is sacred? French psychiatrist Eric Bui analyzed the fictional character of Darth Vader and diagnosed the adversary known as the Dark Lord, with a borderline personality disorder. This prompted others to ask, "Did the Joker suffer from multiple-personalities? Was Freddie Kruger inflicted with intermittent explosive disorder?" The answer is likely, "Yes."
Does this mean researchers and perhaps myself should be examined for symptoms of a delusional disorder, meaning a condition where people confuse fiction with reality? Not so fast! In truth, psychosis or rather characteristics and symptoms of certain disorders are studied and utilized by many writers to create unstable characters.
Why do this? Well, for starters it aids in creating a relatable villain. You may not encounter a Dark Lord in the real world, but perhaps you know or have known someone with similar attributes. A disorder gives a glimmer of humanity and thus, provides a hint or opens the tiniest of cracks for sympathy. This sympathy leads to the sappiest of all hopes, the miniscule ideal of reform, or in the world of fiction, a happy ending. Shakespeare said stories end either in marriage or death, but what happens when you sprinkle in a pinch of psychosis? A few more options become available: timed served with possible reformation of evil ways, or a prison break, revenge, and an ensuing crime spree.