Definition of Narcissistic personality disorder:
Narcissistic personality disorder is a condition characterized by an inflated sense of self-importance and an extreme preoccupation with one's self.
Causes, incidence, and risk factors:
The cause of this disorder is unknown. Narcissistic personality disorder usually begins by early adulthood and is marked by disregard for the feelings of others, grandiosity, obsessive self-interest, and the pursuit of primarily selfish goals.