This is a book written by experts in sleep disorders for neurologists, psychiatrists and sleep specialists, covering the causes, consequences and treatment of all known disorders of excessive sleepiness.
Much of the research into what constitutes excessive daytime sleepiness (EDS) is recent and is covered in depth, although there is no definitive description for making a diagnosis. EDS affect up to 9.5% of the general population and 16.3% of young adults. Unsurprisingly, perhaps, the most common cause is "behaviourally induced insufficient sleep syndrome" - staying up too late in GP-speak.
The neuro-chemistry is covered in detail, including the role of hypocretin (also known as orexin) and other neuro-transmitters, and the role histamine plays in alert mechanisms, explaining neatly why anti-histamines cause drowsiness.
As a GP, I hoped to learn more about chronic fatigue syndrome (CFS). Although there is an excellent section on taking a sleep history and explanations of the real differences between fatigue and sleepiness, CFS is considered amongst the psychiatric causes of sleep disorder.
There are chapters on narcolepsy (which affects 0.03%), breathing disorders, Alzheimers and Parkinson's diseases, as well as restless leg syndrome and many other more esoteric disorders.
This is a fascinating book to dip into for specific topics and for those with a real interest in sleep disorders, but as a cover to cover read is a certain cure for insomnia.
Dr Bridget Osborne is a GP in Conwy, North Wales