June 7, 2010 — A disorder known as sexsomnia, in which people initiate some form of sexual activity while asleep, may be more common than previously thought in those with sleep disorders, according to a new study.
Almost 8% of 832 patients studied at a sleep disorders center reported bouts of sexsomnia — having initiated sexual activity with a bed partner while asleep — and the prevalence of the behavior was three times more common in men than women, Canadian researchers report.
The researchers conducted a review of 832 patients who had been evaluated for a suspected sleep disorder — 428 men and 404 women.
The patients filled out a questionnaire about sleep disorder symptoms, their behaviors during sleep, their degree of sleepiness, fatigue levels, and descriptions of their moods.
Although sexsomnia was found to be more common than expected, researchers say patients rarely mentioned it to doctors.
“There have been no previous studies of how frequently sexsomnia occurs,” says Sharon A. Chung, PhD, of the Sleep Research Laboratory in the department of psychiatry at the University Health Network in Toronto, in a news release. “While our finding of 8% of people reporting sexsomnia seems really a high number, it should be stressed that we only studied patients referred to a sleep clinic. So we would expect the numbers to be much lower in the general population.”
Chung says that only four of the 832 patients complained about sexsomnia during consultations with sleep specialists.
Symptoms of insomnia, fatigue, and depressed mood were similar in the sleep clinic study patients with and without sexsomnia. Both groups had similar rates of smoking and caffeine consumption.
People who reported sexsomnia, however, were twice as likely as other sleep center patients to admit to using illicit drugs (15.9% vs. 7.7%), the researchers say.
Both sleepwalking and sexsomnia are classified as “parasomnias” — episodes that involve undesirable behaviors that occur during arousal from REM sleep or partial arousal from non-REM sleep.
The researchers say the study is the first of its kind to systematically investigate complaints of sexual acts during sleep. The results were presented June 7 at SLEEP 2010, the 24th annual meeting of the Associated Professional Sleep Societies.