‘Sleep drunkenness’ more common than previously thought

A phenomenon known as “sleep drunkenness” may be more prevalent than previously thought, affecting as many as 1 in 7 adults, according to a new study led by a School of Medicine researcher.

 That means as many as 36 million Americans experience this potentially problematic sleep condition, in which they are awakened suddenly in a confused state and may be prone to inappropriate behavior, poor decision-making or even violence.

In interviews with nearly 16,000 adults ages 18 to 102, the researchers found that within the previous year, 15.2 percent experienced the condition, also known as confusional arousal, with more than half saying they had at least one episode a week.

Sleep specialist Maurice Ohayon, MD, DSc, PhD, professor of psychiatry and behavioral sciences at Stanford, said he was surprised at the extent of the problem and particularly the length of time that people reported feeling confused and disoriented following a sudden awakening, whether at night or from a daytime nap.

“I was thinking maybe 30 seconds, a minute or 2 minutes,” said Ohayon, who is the lead author of the study. “When you ask people, 60 percent said it lasted more than 5 minutes. And one third said it was 15 minutes or more. A lot of things can happen in that time.”

“The concern is that people in a job of security, such as engineer, may misjudge the situation because their memory is impaired,” he added. “Their judgment is not taking into account the environment around them, so they will probably have a bad response. The response will not be adapted to the environment.” 

The study was published Aug. 26 in Neurology.

Possible dangers for pilots

Ohayon noted that the 1979 Three Mile Island disaster, the worst nuclear incident in U.S. history, was exacerbated in part by poor decision-making on the part of an engineer who had been awakened suddenly from a nap. He also cautioned that airline pilots, who may nap during a break, may not be efficient for 5 or 10 minutes and should take their time after being awakened before resuming control of an aircraft.

Among the people who are most prone to the condition are those with sleep disorders, such as sleep apnea, or those who sleep less than 6 hours or more than 9 hours a night, as well as people with certain psychiatric disorders, such as major depression, anxiety and alcohol dependence, the researchers found. Ohayon said he was surprised to discover a strong link between the condition and the use of antidepressants, which likely modify sleep architecture and may contribute to a greater incidence of the condition. Though there is a common perception that people who take sleep medications to help them fall asleep may be confused when they wake up, the study did not find that to be the case, he said.

More than a third of the respondents who experienced confusional arousal also said they had hallucinations, and 14.8 percent reported sleep-walking, sometimes accompanied by violent behavior.

“People during confusional arousal can become violent because they are awakened suddenly,” Ohayon said. “They are not happy. They are confused. They may feel aggression toward their partner or the people who have awakened them.”

He said people who experience frequent episodes of confusional arousal should consult with a physician for evaluation and possible treatment. And he urged further study of the problem, which has received little scientific attention.

The study’s senior author is Damien Leger, MD, PhD, at Paris Descartes University. 

The study was funded by the Arrillaga Foundation.