The person with Narcissistic Personality Disorder is said to be dramatic, emotional, and erratic, as are others in Cluster B, but with an additional need or demand for attention, admiration, and special treatment; thus, the narcissistic factor. Just as the young Greek Narcissus was so vain that he fell in love with his own reflection in a pool of water, this patient is vain and egocentric, with a greatly exaggerated sense of self, overestimating both his accomplishments and his failures.

Freud had coined the term narcissism from the Greek myth to represent the kind of grandiosity exhibited by some of his patients. Later, the term was attached to the personality disorder that features a cluster of these related symptoms. In addition to those symptoms mentioned, the pattern of the disorder includes arrogant, haughty behavior, sense of entitlement (unreasonable expectations of favorable treatment), exploitation of others for his own gain, and lack of empathy of others.