Sexsomnia may be more common than previously believed and is more common in men than women, according to new research presented today at SLEEP 2010.   Their results indicate that 7.6 percent of patients (63 of 832) at a sleep disorders center reported that they had initiated or engaged in sexual activity with a bed partner while still asleep.

The prevalence of reported sexsomnia was nearly three times higher in men (11 percent) than in women (four percent).

The International Classification of Sleep Disorders, Second Edition,  notes that sexsomnia appears to occur predominantly during confusional arousals and may occur during an episode of sleepwalking. These are two of the disorders that are classified as "parasomnias," which involve undesirable behaviors that occur while falling asleep, during sleep or while waking up.

A literature review in the June 2007 issue of the journal Sleep concluded that a broad range of sleep-related disorders are associated with abnormal sexual behaviors and experiences.

Symptoms of insomnia, fatigue and depressed mood were similar between people reporting sexsomnia and other patients at the sleep disorders center. Both groups also had similar rates of smoking and caffeine consumption. However, people who reported sexsomnia were twice as likely as other sleep center patients to admit using illicit drugs (15.9 percent vs. 7.7 percent).

The study involved a retrospective chart review of 832 consecutive patients who were evaluated for a suspected sleep disorder; the sample consisted of 428 men and 404 women. Patients completed a questionnaire about sleep disorders symptoms, behaviors during sleep, sleepiness, fatigue and mood.

"There have been no previous studies of how frequently sexsomnia occurs," said co-investigator Sharon A. Chung, PhD, Sleep Research Laboratory staff scientist in the department of psychiatry at the University Health Network in Toronto, Canada. "While our finding of eight percent 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."

Although sexsomnia was common, patients rarely mentioned the problem to their doctor. Chung noted that only four of 832 patients expressed a complaint about sexsomnia during a consultation with a sleep specialist.   "It seems that patients generally don't discuss this with their doctors."