Some of his contemporaries said he was frivolous, mercurial, mundane, uneducated, vindictive, a mythomaniac and, above all, terribly vain and narcissistic to the point of megalomania.
Likewise, feelings of omnipotence or other delusions of grandeur would be considered mood-incongruent symptoms in the case of depression, while they would be mood-congruent in a person experiencing megalomania.