Big Pharma and sleep

Segmented sleep, also known as divided sleep, bimodal sleep pattern, bifurcated sleep, or interrupted sleep, is a primarily biphasic sleep pattern where two periods of nighttime sleep are punctuated by a period of wakefulness. Along with a nap (siesta) in the day, it has been argued that this is the natural pattern of human sleep. A case has been made that maintaining such a sleep pattern may be important in regulating stress.

Historian A. Roger Ekirch has argued that before the Industrial Revolution, segmented sleep was dominant in Western civilization. He draws evidence from documents from the ancient, medieval, and modern world.Other historians, such as Craig Koslofsky, have endorsed Ekirch's analysis.