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Sexsomnia: a contentious diagnosis


Key Points

Sexsomnia is recognised as a rare sleep disorder in which a person engages in sexual activity during their sleep. In general they’ll have no recollection of events during the act or when they wake up.

In this article, we’ve explored both the legal and medical sides of sexsomnia and we’ve covered the following areas:

  • what is sexsomnia: we look at what sleep science can tell us about this rare disorder
  • the causes of sexsomnia and how it can affect the individual and those around them
  • sexsomnia and the law: examples of cases and the difficulties it presents in legal cases
  • how sexsomnia can be successfully treated by lifestyle changes and addressing underlying health conditions.


Sexsomnia (often misspelled as ‘sexomnia’ and sometimes also known as ‘sleepsex’) is a rare sleep disorder which mostly affects men. It’s thought to account for around 7% of referrals to sleep disorders clinic, but the actual value is probably higher as some people may be embarrassed to seek help and others may not realise they have the problem.

Sexsomniacs engage in the following sexual activities while they’re asleep1:

  • sexual vocalisations
  • masturbation
  • fondling
  • intercourse/attempted intercourse.

Sexsomnia is considered a parasomnia, which means a sleep disorder related to abnormal movements.

There are many common parasomnias, and you’ve probably heard of ones such as sleepwalking, sleep paralysis and bedwetting (to name but a few).

Several parasomnias occur during our rapid eye movement (REM) sleep, a good example being sleep paralysis. REM sleep is generally considered to be when most of our dreams occur but sexsomnia occurs during non-REM sleep and isn’t related to dreaming.

As with other parasomnias, sexsomniacs do not remember the acts that they perform while they are asleep.

Although abnormal sexual behaviour during sleep was first described in 1989, the term ‘sexsomnia’ wasn’t coined until 2003 when 11 patients exhibiting sexual behaviours during sleep were described.2

Causes of sexsomnia

Sexsomnia can co-occur alongside other sleep disorders such as sleepwalking, sleep apnoea, night terrors and bedwetting. It may be triggered by:

Treatments that improve the quality of sleep may help to reduce the incidence of events.

Cognitive Behavioural Therapy for insomnia (CBTi) can improve your sleep and mood.

When your sleep improves, it can also reduce levels of stress, anxiety and depression. If you’re having trouble sleeping and you feel like it’s having an effect on your mental and physical wellbeing, Sleepstation’s CBTi programme can help.


The implications of sleepsex

Sexsomnia, by its very nature, can have a profound impact on both the person with the condition and their partners. As people with sexsomnia tend to have no recollection of the events, it can be scary and confusing to learn that they have been carrying out behaviours outside of their conscious control.

For the bed partner, a range of feelings can be expected emcompassing everything from fear to enjoyment. In 2000, groundbreaking work was published recording stories and experiences of people who had experienced ‘sleepsex’.3

In a loving relationship, it may be understood as ‘just one of those things that happens’ as the account below suggests:

Sleepsex is great. My husband initiates it while we’re sleeping and then we wake up in the middle of making love. Often it’s better when he’s asleep because we’re completely relaxed and uninhibited.

However, given the nature of the behaviour, it may be hard for the bed partner to understand the fact that this behaviour is not deliberate:

During his sleepsex episodes, he becomes very aggressive and violent and then claims he does not remember anything… I had to call 911 last night because of a violent assault.

In extreme cases, sexsomnia has led to accusations of sexual assault — including rape — although the condition has been used successfully as a legal defence in some such cases.

A diagnosis of sexsomnia can often leave a person feeling shame, guilt or depression. For both the person experiencing sexsomnia and their partner, it’s crucial to speak to a sleep specialist and often consulting with a therapist may be recommended to help both parties with the diagnosis.

Sexsomnia and the law

A review of 90 cases of sexsomnia in the literature from nine different countries (including the United States and United Kingdom) found that 82% of the offenders were male.4 In 97-98% of cases those charged presented amnesia as a defence.

In about a third of the incidents reviewed there were also reports of aggression and violence. Ultimately, 14% of the cases resulted in legal proceedings.

Sexsomnia is now formally recognised as a psychiatric disorder and has been included in the standard diagnostic manual DSM-55 ― essentially the bible of psychiatric disorders.

However, difficulty in clearly defining such behaviours and the possibility of falsely claiming sexsomnia as a defence can cause difficulties for a judge and jury.6 7 8


Luedecke: a study in sexsomnia

A number of the early legal cases concerning sexsomnia as a defence occurred in Canada — the most important of which was R v Luedecke.9 This case involved a defendant who had attended a party in Toronto in 2003 during which he consumed a large amount of alcohol and some magic mushrooms. Apparently:

  • he had been awake for 22 hours before he fell asleep at about 4am
  • he woke to find he was in the middle of nonconsensual sex and the woman was screaming
  • the woman said Luedecke looked ‘completely incoherent’
  • Luedecke said he was ‘completely dazed and in shock’.

When he learned later that day that police were looking for someone in connection with a sexual assault, Luedecke contacted the police and gave a voluntary statement.

The judge accepted that Luedecke’s conduct was triggered by the external factors outlined by a sleep expert. According to the defence, excessive sleep deprivation, alcohol, genetic predisposition factors and stress all contributed to circumstances beyond their client’s control.

The judge was satisfied that the defence of sane automatism (i.e. the accused was not responsible for his actions because he didn’t have conscious control of those actions) was correct and acquitted Luedecke.


In a legal setting, a defence of sexsomnia is often difficult to establish, as the diagnostic tests needed to diagnose sleepsex are not generally taken into consideration.

Polysomnography is not routinely performed as part of a medicolegal evaluation in part as this diagnostic tool is not associated with the crux of the legal focus upon mens rea with the criminal allegation.10

To put this in layman’s terms, recording sleep behaviour (polysomnography) cannot offer evidence that the accused knew the act they committed was wrong (mens rea is Latin for guilty mind). So while there may be evidence of behaviours that would support the possibility of sexsomnia:

there is absolutely no after-the-fact polysomnograph finding that could possibly have any relevance as to whether the accused was sleepwalking at the time of the event in question.

What this means is that if you record someone’s sleep and discover that it’s normal then it doesn’t mean that it has always been normal — the accused person may have been experiencing sexsomnia in the past even if there’s no evidence for it in the present.

A good example can be seen in the case of State v. Scott8, where overnight sleep recording did not demonstrate unusual sexual behaviours in sleep. In this case, the court accepted an expert’s opinion that Scott exhibited ‘sexual behaviours in sleep parasomnia’ based on the defendant’s sleep history — as well as supporting evidence from family and sleep partners.

Even though the defendant’s sleep recording was normal — and might suggest the likelihood of a deliberate sexual assault — more importance was placed on the historical evidence. It was that evidence which exonerated Scott.

How is sexsomnia diagnosed?

Diagnosing sexsomnia usually relies on completing a sleep study, to try to capture the behaviour as it happens, or having accounts from a partner which, if detailed enough, can be sufficient for a doctor to determine if the behaviour is truly sleepsex.

When a sleep study is undertaken to diagnose sexsomnia, a person will usually spend several nights sleeping at a sleep clinic. During the sleep study, several measurements are taken while you sleep, including:

  • brainwave activity
  • heart rate and respiration rate
  • leg and eye movements.

These can be used to identify or rule out other sleep disorders and ultimately accurately diagnose sexsomnia. If an episode of sexsomnia doesn’t occur during the sleep study then your doctor may recommend undertaking a second study.


Sexsomnia treatment approaches

Sexsomnia is treatable. As sexsomnia can be caused by other underlying sleep disorders, such as obstructive sleep apnoea, treating the primary cause should also help to resolve the sexsomnia.

Reducing intake of alcohol and addressing substance abuse in those with sexsomnia can be beneficial. Taking steps to reduce levels of stressanxiety and depression can also have a positive effect on sexsomnia. Improving sleep hygiene can reduce symptoms.

Identifying measures to improve the overall sleep of someone with sexsomnia should help to reduce their sleep-sex symptoms.

As mentioned earlier, in some instances, talking therapies may be advised to help with processing any negative emotions that a person may be experiencing after receiving a diagnosis of sexsomnia.

If you think you may be experiencing sexsomnia, it’s important that you speak to your healthcare provider about it. Whether your worries are justified or not, leaving them unaddressed could interfere with your sleep and could lead to developing other sleep disorders, such as insomnia.

If you’re looking for sleep advice or want to learn more about how to sleep well, we have a wealth of information available in our articles section, ranging from sleep tips to the science behind everything sleep-related.

And if you’re worried about your sleep or a sleep problem then we can help. Sleepstation’s CBTi progamme is both clinically proven and highly effective, so if you want quality, long-lasting improvements to your sleep, based on decades of sound science, register for Sleepstation today.



  • Sexsomnia is a relatively rare sleep disorder in which the person initiates sexual behaviour while asleep.
  • Numerous causes and triggers of sexsomnia have been identified.
  • Judicial systems around the world deal with the legal implications of sexsomnia differently.
  • Sexsomnia can be treated by addressing any underlying sleep problems and triggers.


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  2. Shapiro CM, Trajanovic NN, Fedoroff JP. Sexsomnia—a new parasomnia? The Canadian Journal of Psychiatry 2003;48:311–317. ↩︎
  3. Mangan M. Sleepsex: Uncovered. Xlibris Corporation; 2001. ↩︎
  4. Schenck CH. Update on sexsomnia, sleep-related sexual seizures, and forensic implications. NeuroQuantology 2015;13. ↩︎
  5. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM-5 (R)). 5th ed. Arlington, TX: American Psychiatric Association Publishing; 2013. ↩︎
  6. Davis C. Sexsomnia–excusable or just insane? Criminal Law Journal 2015;39:21–39. ↩︎
  7. Organ A, Fedoroff JP. Sexsomnia: sleep sex research and its legal implications. Curr Psychiatry Rep 2015;17:34. ↩︎
  8. Mohebbi A, Holoyda BJ, Newman WJ. Sexsomnia as a defense in repeated sex crimes. J Am Acad Psychiatry Law 2018;46:78–85. ↩︎
  9. R. v. Luedecke, 2005 ONCJ 294 (CanLII) Available from:  ↩︎
  10. Cramer Bornemann MA. Sexsomnia: A medicolegal case-based approach in analyzing potential sleep-related abnormal sexual behaviors. Parasomnias, New York, NY: Springer New York; 2013, p. 431–61. ↩︎