Narcissism is the pursuit of gratification from vanity or egotistic admiration of one's idealised self image and attributes. The term originated from Greek mythology, where the young Narcissus fell in love with his own image reflected in a pool of water. Narcissism is a concept in psychoanalytic theory, which was popularly introduced in Sigmund Freud's essay On Narcissism (1914). The American Psychiatric Association has listed the classification narcissistic personality disorder in its Diagnostic and Statistical Manual of Mental Disorders (DSM) since 1968, drawing on the historical concept of megalomania.
Narcissism is also considered a social or cultural problem. It is a factor in trait theory used in various self-report inventories of personality such as the Millon Clinical Multiaxial Inventory. It is one of the three dark triadic personality traits (the others being psychopathy and Machiavellianism). Except in the sense of primary narcissism or healthy self-love, narcissism is usually considered a problem in a person's or group's relationships with self and others. Narcissism is not the same as egocentrism.