Astronauts experience sleep disorders during the weeks before their flight to space and while on their missions, researchers from Brigham and Women's Hospital (BWH) Division of Sleep and Circadian Disorders, University of Colorado and Harvard Medical School discovered.
Their joint study gathered data from at least 4,000 nights of sleep spent on Earth and at least 4,200 nights of sleep spent in space. These were from the records of 64 astronauts who were involved in 80 Shuttle missions, and at least 21 astronauts who worked in the International Space Station. This cohort study, which ran for 10 years, is currently the largest and most comprehensive study to look into the sleep patterns of astronauts.
The study found that, although NASA prescribed 8.5 hours of sleep for every crew member during their mission, each astronaut only spends an average of 5.96 hours of sleep while on duty, and only six hours when working in the International Space Station. Only 12 percent of sleep episodes recorded for shuttle mission lasted for more than seven hours, while 24 percent of the ISS crew members slept for more than seven hours.
The research also found out that astronauts develop sleep deficiency during the weeks before they go to space.
"Sleep deficiency is pervasive among crew members," Laura K. Barger, PhD, associate physiologist in the BWH Division of Sleep and Circadian Disorders and lead study author, said in a press release. "It's clear that more effective measures are needed to promote adequate sleep in crew members, both during training and space flight, as sleep deficiency has been associated with performance decrements in numerous laboratory and field-based studies."
Aside from the disturbed sleeping pattern, the researchers also found that astronauts are highly dependent on sleeping pills while they're in space. About 75 percent of ISS crew members admitted to taking sleeping pills while on site, and 78 percent of shuttle mission astronauts reported their use of sleeping pills for 52 percent of their stay in space.
Further details of the study were published in the Aug.8 issue of The Lancet Neurology.
