Prevalence is the estimated population of people who are managing Narcissistic Personality Disorder (NPD) at any given time in a given general population group. Jean M. Twenge PhD and W. Keith Campbell PhD, authors of the 2009 book The Narcissism Epidemic, estimated the prevalence of NPD in the United States at 6.2% in the general population: 7.7% for males and 4.8% for females. Reportedly, NPD is more prevalent among separated, divorced, widowed, and never married adults. Hispanic females and African Americans may be at higher risk. It comes as no surprise NPD can cause problems in many areas of life including home, school, work, and in all types of relationships and collaborative efforts. This personality disorder is also characterized by a belief that they deserve admiration and special favors in all environments. When they do not receive this at the level expected, they can become disappointed and unhappy. Naturally, they tend to find relationships rather unfulfilling and cannot seem to understand why others to not seek them out and want to be around them. More tomorrow.