Overview

While sleeping, people can experience different involuntary physical events, such as speaking, unconscious movements, or performing unusual activities; these are known as parasomnias. One of these disorders is sexsomnia, which is the presence of sexual behaviours during the sleep cycle without remembering them.¹ It is also known as somnambulistic sexual behaviour, sleep-related abnormal sexual behaviours, sexual behaviours during sleep, atypical sexual behaviour during sleep, or sleep sex.^{2, 3} 

Being aware of sexsomnia is helpful to understand the diverse implications that persons with this disorder can have and to recognise more cases. Usually, this parasomnia is underdiagnosed, and the cases reported are low in comparison with other sleeping disorders.^1,2

In 2007, a classification of sleeping disorders associated with sexual behaviours was created for the first time. It was made considering the inconveniences for the bed partner and the person affected by these conditions.³ To understand sexsomnia better, we will first analyse some related topics. 

Sleep cycle and phases

Sleeping occurs in cycles; each cycle is divided into 2 main phases: non-rapid eye movement (NREM) and rapid eye movement (REM). 

• Non-rapid eye movement (NREM): it is divided into 3 stages. Stage one is when we pass from being awake to asleep; in stage two we are sleeping; and in stage three we are in a deep sleep
• Rapid eye movement (REM): As its name implies, in this phase, our eyes move rapidly, and brain activity is similar to when we are awake; almost all of our dreams happen during this time
• Every night we have between 4 and 6 cycles with little awakenings between them; every cycle lasts approximately 90 minutes, although the duration varies⁴ 

Classification of parasomnias

The third edition of the International Classification of Sleep Disorders divides parasomnias depending on the sleep phase where they are presented ⁵

1. Non-rapid eye movement (NREM) related: confusional arousal, sleep terror or night terror, sleepwalking, sleep-related eating disorder
2. Rapid eye movement (REM)-related: nightmare disorder, recurrent isolated sleep paralysis, REM sleep behaviour disorder
3. Others: Sleep enuresis, sleep-related hallucinations, parasomnia related to a medication, parasomnia related to a medical disorder, or unspecified parasomnia

According to the classification, sexsomnia is a subtype of confusional arousal, which is when someone looks like being awake but has strange behaviours, such as confusion or disorientation.⁶ Both are part of NREM parasomnias; these parasomnias share the following features:⁵

• The person is not completely awake
• The stimulus-response is inappropriate or incomplete
• There is limited or no consciousness about the episode 
• There is amnesia (the person cannot remember what happened)

Characteristics of sexsomnia

Sexsomnia involves sexual behaviours that a person has while sleeping but seems like being awake. Examples of these conducts are sexual vocalisations, masturbation, touching the bed partner in a sexual way, intercourse, or trying to perform intercourse.^{1, 6} These episodes occur unexpectedly with a duration of no more than 30 minutes.⁸

Despite the lack of reported cases, it has been estimated that there might be a 7.1% probability of having at least one episode, during a lifetime, related to sexual acts while sleeping in the general population.⁹ 

Unknown origin

There is no clear origin for the specific causes of sexsomnia.⁷ It is related to abnormal brain activity during stage 3 of NREM, where deep sleep occurs. However, there have been reported cases where sexsomnia is associated with REM parasomnias and frontal lobe seizures.^1,7,10 

Usually, people with this condition do not look for medical help because they feel ashamed or they do not understand what is happening to them. These factors make it difficult to learn more about sexsomnia.⁷ 

Risk factors

There are different types of risk factors that have been associated with sexsomnia; they will be analysed below. 

Predisposing factors

Antecedents of the presence of parasomnias in parents, grandparents, or siblings are related to a higher risk of suffering.⁸ 

According to the cases reported, it tends to be more common in young people assigned male at birth, with behaviours such as masturbating or trying to perform intercourse, than in people assigned female at birth, where the behaviours related are intercourse, masturbating, and/or experiencing sleep-related orgasms.^1,3,11,12 

Priming factors

The use of alcohol and/or other recreational drugs is related to parasomnias in general, In the case of sexsomnia, the initiation of drugs is an important risk factor.^8,11

Circumstances that cause inadequate rest, such as sleep deprivation, stress, or fever can also trigger sexsomnia.⁸

Precipitating factors

The presence of external noises can precipitate episodes of sexsomnia.⁸

Another important precipitating factor is to be affected by another parasomnia. It has been calculated that in approximately 73% of cases, people have another parasomnia besides sexsomnia.^3.11. There are cases reported of having sexsomnia combined with sleepwalking or sleep-related eating disorder.²

Co-occurrence with other conditions

Next, we will analyse some conditions and sleep disorders that have been linked with sexsomnia.

Bruxism

Bruxism is the involuntary movement of clenching or grinding the teeth. This can happen during the day or while sleeping; precisely, its presence while sleeping has been associated with sexsomnia.^2,8 There have been reported cases where both conditions happen at the same time during the sleep cycle.² 

Sleep-related breathing problems 

The most common of this kind of disorder associated with sexsomnia is obstructive sleep apnoea. This happens when you snore and stop breathing while you are sleeping. The correction of this disorder with different devices has been helpful in stopping the episodes of sexsomnia.^2,10

Restless leg syndrome

Another sleeping disorder linked with sexsomnia is restless leg syndrome.⁸ People with this syndrome, after feeling uncomfortable sensations while they are lying down, have the urge to move their legs.

Diagnosis

It is crucial to look for medical help, as obtaining a diagnosis requires that the doctor perform a record of the antecedents and the actual condition of the person. Additionally, keeping a sleep diary is helpful because the person and the bed partner can describe how often the episodes are, what happens during the episodes, as well as their duration.⁸ With this information, it is possible that the person needs to be referred to a sleep specialist.

Besides there are different tests that are useful for the diagnosis:²

• Sleep study (polysomnography): This test records brain activity, eye movements, heartbeat, and breathing while being in a sleeping laboratory to register the different parts of the sleep cycle
• Electroencephalogram (EEG): In this study, the electrical activity of your brain is registered

Treatment

Treatment requires different aspects that we will analyse below.

Pharmacotherapy

Clonazepam is the usually prescribed medication for sexsomnia and other parasomnias and sleep disorders.^6,7 It is helpful to activate calming substances inside the brain. Other medications used in parasomnias are antidepressants, such as paroxetine, because they help to diminish the awakenings.^1,6 

Safe environment

The person and bed partner must take actions that maintain a safe environment for both.⁶ For example, avoid having knives or other items that can cause injuries near the bed. In addition, persons with sexsomnia must not sleep with persons who are not their usual bed partner.

Sleep hygiene

There are general measures that are useful to improve the quality of sleep; these are known as sleep hygiene. 

Consequences of sexsomnia

Due to the behaviours that this condition triggers, there have been cases of rape of friends or family members, violent episodes against the bed partner, loss of child custody, and suicidal thoughts.^{1, 7, 11} This parasomnia can have a huge impact on the person that is affected and the people around them. is why it is essential to look for medical help if someone near you might have it.

Summary

Sexsomnia is part of sleeping disorders known as parasomnias. Its relevance is because it can cause the presence of unwanted sexual behaviour while sleeping. Persons with sexsomnia do not always look for medical help, and there are unreported cases. In addition, people with this condition can harm their bed partner or close relatives and friends. Hence, that people be aware of its existence is of high relevance.