From history and fiction to philosophy and poetry, Marina Benjamin reveals to The Guardian the works that helped her understand an unsettlingly common problem.
5. Awakenings by Oliver Sacks
In 1917, a strange epidemic of sleep sickness swept the globe, causing thousands of people to collapse with raging fevers and wild hallucinations before falling into spells of extended sleep. Sacks worked with survivors of this epidemic 40 years later, after neurologists found that administering the drug levodopa could jolt the long-slumbering victims into periods of manic wakefulness.