How Sleep Sex (and Other Parasomnias) Can Get You in Trouble with the Law

Criminal cases sometimes arise when people with these strange disorders act out while asleep.

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Many people have so-called parasomnias, or involuntary behaviors—sleepwalking being the best known—that they act out while they're asleep. While it's rare for parasomniacs to get entangled with the law, sometimes they do. Sleep eating or calling a friend while unconscious isn't likely to get someone in legal trouble. But certain parasomnias, like sleep sex, may pose a greater legal liability, say sleep experts Carlos Schenck and Michel Cramer Bornemann, both of the Minnesota Regional Sleep Disorders Center at Hennepin County Medical Center in Minneapolis. Here are four parasomnias they believe to be the most legally problematic, based on their clinical experience and on requests they've received from lawyers and others to review legal cases.

Sleep sex. Sexsomnia, aka sleep sex, causes people to engage in sexual behaviors while asleep. Those behaviors might simply be sexual noises or dirty talk, or they might involve masturbation, fondling, or even initiating intercourse. Sleep sex may have played a factor in dozens of legal cases that have been referred to Sleep Forensics Associates, a group formed by Cramer Bornemann, Schenck, and a colleague of theirs in 2006. While sexsomnia might not have caused the alleged criminal act in every case, sleep sex does seem to be among the most legally problematic of parasomnias, Schenck says.

Sleepwalking. Formally known as somnambulism, sleepwalking, too, can be a problematic. Walking, of course, isn't a crime. But people can perform incredible complex and occasionally violent acts while they're sleepwalking. In one case, a sleeping woman cut up her cat on a cutting board. "Once these behaviors leave the bedroom, it's not a personal problem anymore, it [becomes] a public safety concern," says Cramer Bornemann. SFA has so far received more than 15 requests to review cases involving sleepwalking-related violence. The group also has published reports suggesting that deaths are sometimes mislabeled as suicides when sleepwalking or another parasomnia could have been the cause. Neurophysiological studies of sleepwalkers' brains indicate they're neither fully asleep nor fully awake but somewhere in between.

Sleep driving. One example of how sleepwalking can lead to other complex sleep behaviors is that people can grab their keys, get in their cars, and go cruising—all while asleep. Sometimes the ride passes without incident. Sometimes not. Most of the cases of sleep driving that have come to SFA's attention have been associated with possible use of sleeping pills.

Medication-induced parasomnias. Overall, roughly a third of SFA's requests for case evaluations involve zolpidem toxicity, or the alleged influence of the prescription sleep aid Ambien (generically known as zolpidem), says Cramer Bornemann. That may be related to how widely Ambien is prescribed, he says, adding that he has seen parasomnia cases associated with other sleep aids. While DUI arrests top the list of crimes associated with zolpidem-induced parasomnias, other acts—including sexual crimes, assaults and nonlethal violence, and even homicides—have been blamed on medications in some instances. (Neither Cramer Bornemann nor his associates at SFA have financial ties to the pharmaceutical industry.)

In 2007, the U.S. Food and Drug Administration asked manufacturers of all prescription sleep aids to revise their labels to warn of the risk of rare but serious side effects, like sleep driving and other complex sleep behaviors. That was in response to a few dozen reports the agency had received. Agency officials acknowledged in a media briefing that other cases could be escaping their attention. "We do believe that all of the drugs in the class are capable of producing these adverse events," the FDA's Russell Katz told reporters. To minimize risks, he said, consumers of prescription sleep aids might refrain from simultaneously using alcohol and other drugs that depress the nervous system, and they should not use more than the recommended dose of any sleep aid.