Reddit user Rain 12913 claims to be a psychologist and offered analysis and diagnosis for the character Cersei Lannister on Game of Thrones. She's a fictional character, which the psychologist was quick to point out. But it's fun to use a real life diagnosis to explain the driving motivations of Cersei. It turns out she has a personality disorder. The fact that she cares mostly about herself—or people with personalities that are nearly identical to hers—makes her a classic narcissist. As always, there are a whole bunch of spoilers for the series ahead.

Sources: Mashable | Diagnostic and Statistical Manual of Mental Disorders