Narcissism was a personality trait characterized by a higher-than-normal opinion of oneself.
Starfleet considered the Son'a to be a narcissistic species. (Star Trek: Insurrection)
In 2151, while designing what would become the tactical alert, Malcolm Reed received a suggestion from Trip Tucker to call it the "Reed alert". Reed considered the idea, but rejected it as too narcissistic. (ENT: "Singularity")
In a scene from the script of Star Trek but not the final movie, Spock characterized the Kobayashi Maru scenario as intended to elicit fear of certain death, as an antidote to narcissism. He further implied that Vulcan training included the control of narcissism.