He begins the most famous work in the Italian language "full of sleep" and with a "weary body", and, throughout the Divine Comedy, Dante Alighieri recounts vivid dreams and brief naps. On one occasion, he tells of being awakened with "rested eyes". On another, overcome by emotion, he describes falling to the ground "like a dead body".
Now, an Italian academic has come up with an explanation for why the Florentine poet was apparently so obsessed with slumber – and it's not all about literary technique. Dante, he argues, may have suffered from the neurological disorder narcolepsy.
"I suggest that six centuries before the first scientific report, Dante … depicted narcolepsy with cataplexy (NC) in his literary works as an autobiographical trait," writes Giuseppe Plazzi of the University of Bologna's department of biomedical and neuro-motor sciences in an article for the Sleep Medicine journal.
"Although some features may represent literary devices, it is difficult to argue that this descriptive accuracy is accidental," says Plazzi. "It appears to be a plausible hypothesis that Dante's sleep, dreams, hallucinations and falls are all clues to a lifelong pathologic trait, and that Dante either knew of or had this rare central nervous system hypersomnia."
In his article, Plazzi details numerous points in the Divine Comedy (Divina Commedia) where Dante, as author and narrator, appears – if taken literally – to be describing symptoms of narcolepsy and cataplexy.
A term first coined in 1880 by French scientist Jean-Baptiste Edouard Gélineau, the former is a chronic neurological condition caused by the brain's inability to regulate sleep patterns normally. It can cause people to have disturbed nocturnal sleep, feel sleepy during the day and sometimes drop off without warning.
Narcolepsy is sometimes accompanied by cataplexy – temporary muscular weakness often brought on by emotion.
According to Plazzi, both of these can be seen in Dante's work, particularly his 14th-century epic poem in which his narrator travels through hell, purgatory and heaven. On the way, Plazzi notes, he experiences "sudden wake-dreaming transitions, short and refreshing naps, visions and hallucinations, unconscious behaviours, episodes of muscle weakness, and falls which are always triggered by strong emotions".
"Despite almost seven centuries of research, the lack of direct sources and autographic material mean that little is known about Dante's life and personal traits," writes Plazzi. "However, his writings represent a main biographic source of the poet's life, as Dante himself is the main character in his literary works."
Plazzi is not the first person to seek to diagnose Dante. A 19th-century criminal anthropologist, Cesare Lombroso, speculated that il sommo poeta (the supreme poet) had epilepsy. But Plazzi discounts this theory, arguing that the way in which Dante describes an apparent epileptic seizure is completely different from the emotional falls he – as narrator – experiences.
Photograph: Heritage Image Partnership/Alamy
• This article was amended on 25 September 2013 to make clear that some phrases in the first paragraph were quotations from Dante.
