Megalomania is defined as:
It is derived from the (from the Greek word μεγαλομανία; megalo-, meaning large, and mania) The first attested use of the word "megalomania" is in 1890 as a translation of the French word "mégalomanie".
The word "megalomania" does not appear in the Diagnostic and Statistical Manual of Mental Disorders (DSM) or the ICD. Grandiosity and delusions of grandeur have similar meanings to megalomania and are used in the DSM and ICD as possible symptoms of several mental conditions.
A famous quotation by Bertrand Russell gives his interpretation of megolamania: "The megalomaniac differs from the narcissist by the fact that he wishes to be powerful rather than charming, and seeks to be feared rather than loved. To this type belong many lunatics and most of the great men of history."
During his final years, and especially after the death of Hephaestion, Alexander began to exhibit signs of megalomania and paranoia. His extraordinary achievements, coupled with his own ineffable sense of destiny and the flattery of his companions, may have combined to produce this effect.
Bush on the Couch: Inside the Mind of a President is a 2004 book by psychoanalyst Justin Frank. The central premise of Frank's book is that President George W. Bush displays signs of poor mental health which makes him ill-suited to rule the U.S. Frank suggests Bush suffers from megalomania, that he is probably incapable of true compassion and shows signs of sadism, and that as an untreated alcoholic, is in constant danger of a relapse.