Monday, June 7, 2010

Two U.S. military supported studies find bright lights can improve alertness, reduce post-traumatic stress


A series of brief flashes of bright light is all it takes to improve alertness at night, as reported in a research abstract (#0257) presented Monday at SLEEP 2010.

Test subjects were wakened two hours after their typical bedtimes, brought into a dark room and were exposed to a two-millisecond light pulse once a minute for an hour.

Researchers at Stanford University noted a significant improvement in self-rated alertness and reaction time, as measured by the auditory Psychomotor Vigilance Test.

The subjects also spent an hour in darkness at a different time and date showed no improvements.

“We found it shocking that light exposure as brief as a few milliseconds could engender changes in alertness and brain wave activity,” said lead researcher Jamie M. Zeitzer, PhD. “These results change the manner in which we think about the brain’s capacity to respond to light.”

These findings could lead to a breakthrough for shift workers and military personnel, who are often required to go days without sleeping during wartime deployment.


Another study (# 0706) on display offers new hope for troops returning from battle with Post Traumatic Stress Disorder.

Researchers found bright light therapy greatly reduced the sleep disturbances specific to PTSD. The treatment also produced a moderate improvement in other PTSD symptoms and depression.

16 soldiers participated in the study after returning home to the U.S. from Afghanistan or Iraq with combat-related PTSD.

Half of the troops received 30 minutes a day of 10,000 lux bright light therapy for one month. The other half received a sham treatment as a placebo.

At the onset and immediately following treatment the soldiers were given the clinician-administered PTSD scale. The troops also completed weekly depression and sleep quality assessments.

Bright light therapy typically involves exposure to up to 10,000 lux of light for scheduled periods of 20 minutes or more. The technique can decrease sleepiness and improve alertness by suppressing the production of melatonin, a hormone that tells your body when its time to sleep.
Images courtesy the U.S. Army

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