Narcisstic Personality Disorder

    I have had a theory that people who hog Facebook pages, such as those who post a half-dozen status updates daily or countless selfies, may have a mental disease known as Narcissistic Personality Disorder.  I stumbled upon this disorder while searching demographics of psychopathology. According to a Wikipedia reference https://en.wikipedia.org/wiki/Narcissistic_personality_disorder   

People with narcissistic personality disorder are characterized by exaggerated feelings of self-importance. They have a sense of entitlement and demonstrate grandiosity in their beliefs and behavior. They have a strong need for admiration, but lack feelings of empathy.

The reference continues with

A nationwide study in the United States found that 7.7 percent of men and 4.8 percent of women could be diagnosed with narcissistic personality disorder (Stinson et al., 2008). These data also suggest that narcissistic personality disorder is more prevalent among younger adults, possibly supporting the impression that narcissistic personality disorder is on the rise as a result of social and economic conditions that support more extreme versions of self-focused individualism (Bender, 2012)

Of course this research didn't mention Facebook, but surely I am onto something.