The treatment had two components: brief, early morning flashes of bright, broad-spectrum white light to reset the teens' circadian clocks, and cognitive behavioral therapy that motivated them to try earlier bedtimes. The findings will be published online Sept. 25 in JAMA Network Open. "Using a passive light therapy during sleep, we can help teens get an extra 43 minutes of sleep every single night," said senior author Jamie Zeitzer, PhD, associate professor of psychiatry and behavioral sciences. The light was delivered by a device in the teens' bedrooms that was programmed to deliver 3-millisecond flashes of light every 20 seconds during the last few hours of sleep. The brief flashes of light did not wake the teens. Zeitzer's previous research on jet lag had shown that exposure to short flashes of light can trick the brain into adjusting to a new time zone, even during sleep. - www.sciencedaily.com