About 20 percent of Americans suffer moderate to excessive daytime sleepiness and 11 percent experience severe sleepiness, according to a study from the American Academy of Sleep Medicine and presented in Texas at SLEEP 2010, the annual meeting of the Associated Professional Sleep Societies LLC.

“The number of individuals sleepy or drowsy during situations where they should be alert is disturbing,” said Maurice Ohayon, MD, professor of psychiatry at Stanford University at California and the study's lead investigator. “Sleepiness is underestimated in its daily life consequences for the general population, for the shift workers and for the people reducing their amount of sleep for any kind of good reasons. It is always a mistake to curtail your sleep.”

Researchers surveyed 8,937 men and women in Texas, New York and California about their sleep habits, health, sleep problems and mental health using Sleep-EVAL (a computer program designed to improve identification and treatment of sleep problems).

Findings showed 18 percent of participants previously slept through or became drowsy during crucial meetings and conversations. The research also found that people with sleep apnea were three times more likely to be sleepy in these situations.

In addition, the study showed people who slept six hours or less or who were diagnosed as insomniacs were twice as likely to be drowsy during the day. Night workers and those with major depressive disorders were nearly two times as likely experience sleepiness.

Overall, more women (13 percent) than men (8.6 percent) reported experiencing severe sleepiness.

These results sound the alarm about sleepiness causing workplace injuries and drowsy-driving car accidents, warned sleep medicine experts.

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