Slow Wave Sleep Deficiency Insomnia: A Problem in Thermo‐Downregulation at Sleep Onset

The following review article attempts to develop the argument that a regulated, rapid drop in rectal, core‐body temperature following sleep onset is a necessary prerequisite to the presence of sustained slow wave sleep (NREM Stage 4). Based upon this premise, a theory1 is presented to suggest that the slow wave sleep deficiency so commonly associated with chronic, primary insomnia (Gaillard, 1976, 1978) is the result of a failure in the thermoregulatory system to show a regulated, rapid decrease in body temperature with sleep onset which persists for the first 1–2 hrs into the sleep period.