Risk factors

Narcissistic personality disorder affects more males than females, and it often begins in the teens or early adulthood. Keep in mind that, although some children may show traits of narcissism, this may simply be typical of their age and doesn't mean they'll go on to develop narcissistic personality disorder.

Although the cause of narcissistic personality disorder isn't known, some researchers think that in biologically vulnerable children, parenting styles that are overprotective or neglectful may have an impact. Genetics and neurobiology also may play a role in development of narcissistic personality disorder.