Sleep

Dr David Wheatley discusses the variations of individual sleep requirements, and classifies five main causes of insomnia: physical, physiological, psychological, iatrical and idiopathic. The various aspects of treatment are discussed and the use of sedative drugs illustrated. Dr Ian Oswald describes the two types of sleep, paradoxical and orthodox, and the effects of drugs upon them. He emphasizes the fact that all the common drugs of dependence suppress paradoxical sleep. Professor H Hediger considers the sleep patterns in the animal world and shows how these are adapted to the survival of individual species. Appreciation of the past and the future, which animals do not possess, may be a factor in human sleep disturbances.