Sleep and sleep disorders in Franz Kafka's narrative works.

OBJECTIVE: As Franz Kafka, one of the most important writers of the 20th century, suffered from severe chronic insomnia disorder and inadequate sleep hygiene that impaired his quality of life, we speculated that sleep disorders would be found in his narrative works.

METHODS: We read Kafka's complete literary works looking for references to sleep and sleep disorders, excluding insomnia.

RESULTS: In Kafka's works, sleeping well and for a long time was used as an allegory of having a pleasant life. We found that some of his characters were disturbed by excessive daytime sleepiness and sleep attacks, circadian rhythm sleep-wake disorders, sleep-related hallucinations, sleep symptoms in the context of heart failure and abnormal sleep behaviors (eg, sleep-talking, sleep-crying, sleep-laughing and dream-enacting motor manifestations). Kafka also recalled a dream where bruxism occurred.

CONCLUSION: Kafka's narrative works contain characters suffering from a wide variety of sleep disorders which in some cases represent autobiographical elements but not in others indicating that he was an astute observer of people, sleep and its disorders. The inclusion of characters suffering from sleep disorders was used by Kafka as a literary resource to enrich his texts.