[I received a copy of this book through NetGalley, in exchange for an honest review.]
There’s a wealth of information in this book, sometimes in the text, and sometimes through the references it offers—I’ve picked in those a couple of books I’ll need to read at some point.
“Sleepyhead” is probably more interesting if one is already suffering from sleep-related troubles, maybe not as bad as narcolepsy, but even temporary troubles, such as acute insomnia caused by stress. It goes through a certain amount of factors that trigger narcolepsy and other “X-somnias”, providing details about how misdiagnosed those used to be historically, and helping understand what they entail. For instance, I always thought that narcolepsy was about people falling asleep at any time of the day, but it had never occurred to me that their sleep at night was highly disturbed, and not the peaceful slumber one would imagine from that very basic description. I’m glad I know more about it now.
The book was also interesting for its insights about sleep in general, though the focus remains on the dysfunctional parts: it seems that over the centuries, lots of superstitions (like “incubi”) were in fact descriptions of parasomnia-induced symptoms, such as night terrors. I also didn’t know about the two-time sleep people seemed to have had before artificial lights: sleeping early for a few hours, then being awake for 1-2 hours in the dead of night, then sleeping again for a few more hours.
While note a bona fide scientific book, “Sleepyhead” is useful no matter what: for the journey it describes (Henry Nicholls went to meet and interview many people while researching), and for the information it provides. It could be beneficial for people who suffer from such troubles, sleep apnea for instance, if only to alert them in a “hey, that sounds exactly what -I- am going through!” way.