Narcissistic personality disorder, characterized by an inflated sense of self-importance and the need for constant attention, has been eliminated from the upcoming manual of mental disorders, which psychiatrists use to diagnose mental illness. As Charles Zanor reports in today’s Science Times, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders — due out in 2013 and known as D.S.M.-5 — has eliminated five of the 10 personality disorders that are listed in the current edition. The best known of these is narcissistic personality disorder. It is a puzzle why the manual’s committee on personality disorders has decided...