It is not just a question of bloodshot eyes anymore. After sleepless nights, a person's ability to judge men and matters too gets hampered, it has been found.
Sleep deprivation lowers metabolic activity in the brain region, William D S Killgore and colleagues at Walter Reed Army Institute of Research, report in the journal Sleep.
When they subjected a group of volunteers to two sleepless nights, they found that participants were unable to make balanced decisions when confronted with some difficult choices.
Some even changed their view of what was morally acceptable after they had been awake for two days.
The US military currently is investigating how little sleep soldiers can make do with. Also experiments are on to see whether drugs can help soldiers stay alert for longer without sleep.
Not just soldiers, even medical professionals, who have to make quick decisions in a crisis, would have serious problems if deprived of their sleep, the army researchers note.
A few years ago the British journal Occupational and Environmental Medicine, came out with a report saying that sleep deprivation could have some of the same hazardous effects as being drunk.
Getting less than 6 hours a night can affect coordination, reaction time and judgment, the research authors had said, posing "a very serious risk." Drivers are especially vulnerable, they had warned.
Sleep deprivation may have an adverse impact on mental health too. For Lack of sleep may aggravate anxiety-related disorders, other studies have shown.