Hubris Syndrome described by David Owen and Jonathan Davidson “extreme hubristic behaviour is a syndrome, constituting a cluster of features (‘symptoms’) evoked by a specific trigger (power), and usually remitting when power fades. ‘Hubris syndrome’ is seen as an acquired condition, and therefore different from most personality disorders which are traditionally seen as persistent throughout adulthood.
The key concept is that hubris syndrome is a disorder of the possession of power, particularly power which has been associated with overwhelming success, held for a period of years and with minimal constraint on the leader”
Brain, Volume 132, Issue 5, May 2009, Pages 1396–1406,