Megalomania
Megalomania was a mental condition characterized by the patient's overly high opinion of themselves and a need to be praised.

In 2374 in the alternate timeline known as the "Year of Hell,"  Tom Paris stated to Commander Chakotay regarding Captain Annorax's belief that time had a personal grudge against him, "That's called paranoia, Chakotay, with a hint of megalomania." ()

In 2375, Tom Paris, while explaining to Kathryn Janeway how to treat Doctor Chaotica in the The Adventures of Captain Proton holoprogram, described Chaotica as a megalomaniac and suggested she appeal to his ego. ()

In 2377, The Doctor stated that the hologram Iden had been exhibiting some of the classic signs of megalomania, seeing himself as a spiritual leader who was trying to enlarge his flock. ()

External link

Psychological conditions