"Such behavior is not often mentioned to physicians because of feelings of shame of patients and bed partners," writes Christian Guilleminault, MD, professor of psychiatry and behavioral sciences at Stanford University in Palo Alto, Calif., who published a number of case studies on the subject in the March/April 2002 issue of Psychosomatic Medicine. "But just this morning, I have five emails asking how to get help for this."
On his website (www.sleepsex.org/) Michael Mangan, PhD, an adjunct professor of psychology at the University of New Hampshire in Durham and author of the e-published book, Sleepsex: Uncovered, elicited dozens of descriptions of this behavior from respondents on the Internet.
"My husband has a difficult time falling asleep at night," wrote one woman. "Within that first hour after he finally falls asleep, he will initiate sex with me. He is a very different person while doing this, much more aggressive, groping and playfully biting me. I used to think he was awake and doing this consciously until I would confront him the following day and he wouldn't have any recollection of what he did."
This woman goes on to say that she came to like this aspect of their relationship, but this is not always the case. Another respondent's 16-year-old sister awoke to find her 26-year-old brother-in-law on top of her. "He swears he doesn't remember doing anything like that at all," Mandan's correspondent writes, "and I believe him." Other cases have been documented of sleeping males accosting young children, and legal action has resulted.
In some of the cases described by Guilleminault, sleep sex can be "rape or rape-like behavior." In one case, the bed partner was advised to sleep in a locked room until the patient could be properly diagnosed and treated.
Sleep sex is not limited to men. In several cases in the Stanford study, women had started moaning ("with sexual undertones," the researchers noted) within a few minutes of falling asleep. In another case, a woman had started fondling herself violently and compulsively while sound asleep.
Another study at Stanford, Guilleminault says, indicated that as many as 2% of the general population has become violent while asleep. "We think 1% of the population may have sleep sex," author Mangan says.