Hypergraphia
Appearance
Hypergraphia is the uncontrollable urge to write.
It is not a formally-recognized disorder, although it has been embraced by neurologist Alice Weaver Flaherty in her book The Midnight Disease: The Drive to Write, Writer's Block, and the Creative Brain.
Many weblog authors and diarists, as well as some professional authors, have been accused of suffering from the affliction.