Narcissistic personality disorder is believed to affect around 6 percent of people nationwide, but is more prevalent in younger people. Thus, a major National Institute of Health study found that 9.4 percent of Americans in their early twenties experienced episodes of narcissistic personality disorder.
Narcissistic personality disorder is one of the more difficult personality disorders to diagnose, because the symptomology can be mistaken for other mental health conditions or simply difficult personality traits. Beyond demonstrating narcissistic behavior, a narcissist typically has grandiose ideas about themselves and their life, and seeks excessive admiration from other people and society as a whole. Furthermore, they become fixated on external success and control. Therefore, narcissists tend to lack the ability to empathize. Thus, they do not feel compassion for or identify with other people.
Narcissists tend to have denigrating, dismissive attitudes toward other people. Consequently, the symptoms of narcissistic personality disorder often disrupt personal or professional relationships. However, such narcissistic behaviors tend to hide feelings of low self-esteem and fear of personal inadequacy.
Narcissistic personality disorder was originally identified to describe personality disorders that could not be classified as either neurotic or psychotic. Moreover, narcissistic personality disorder is more widespread in males than females.
Sources: Narcissistic Personality Disorder DSM-5 301.81, US National Library of Medicine (NIH), American Psychological Association