Sleep and sexual offending

Alcohol and Parasomnias: The Statistical Evaluation of the Parasomnia Defense in Sexual Assault, Where Alcohol is Involved

Sleep sex may be a defense for alleged sexual assault. The International Classification of Sleep Disorders (ICSD3) states: "Disorders of arousal should not be diagnosed in the presence of alcohol intoxication… The former [alcohol blackouts] are exponentially more prevalent." A panel member of ICSD3, quoting ICSD3 asserts: "alcohol intoxication should rule out a sleep-walking defense". This implies extremely strong support for a prosecution hypothesis (H_p ) over a defense hypothesis (H_d ). I use Bayesian methodology to evaluate the evidential probity of alcohol intoxication. The likelihood ratio, LR, measures the amplification of prior odds of guilt, LR = Posterior odds of guilt after considering alcohol intoxication /Prior odds of guilt before considering alcohol intoxication . By Bayes' theorem, LR = p ( alcohol intoxication, given H p ) / p ( alcohol intoxication, given H d ) . I use data from cross-sectional studies of sexual assault and prevalence of alcohol use, in college students, with data from longitudinal studies, and data from the epidemiology of parasomnias to evaluate LR (alcohol). LR ~1.5 or 5, depending whether alcohol does, or does not, increase the risk of parasomnias. The proposition of extremely strong support for H_p implies a LR ~1,000,000, so the proposition in ICSD3 is not supported by formal analysis. The statistical reasoning in ICSD3 is unclear. There appears to be inversion of the Bayesian conditional (confusing intoxication given assault, and assault given intoxication) and failure to evaluate alcohol intoxication in H_d . Similar statistical errors in R. v Sally Clark are discussed. The American Academy of Sleep Medicine should review the statistical methodology in ICSD3.

Sleep-related violence and sexual behavior in sleep: a systematic review of medical-legal case reports

OBJECTIVE

To review systematically medical-legal cases of sleep-related violence (SRV) and sexual behavior in sleep (SBS).

SEARCH METHODS

We searched Pubmed and PsychINFO (from 1980 to 2012) with pre-specified terms. We also searched reference lists of relevant articles.

SELECTION CRITERIA

Case reports in which a sleep disorder was purported as the defense during a criminal trial and in which information about the forensic evaluation of the defendant was provided.

DATA EXTRACTION AND ANALYSIS

Information about legal issues, defendant and victim characteristics, circumstantial factors, and forensic evaluation was extracted from each case. A qualitative-comparative assessment of cases was performed.

RESULTS

Eighteen cases (9 SRV and 9 SBS) were included. The charge was murder or attempted murder in all SRV cases, while in SBS cases the charge ranged from sexual touching to rape. The defense was based on sleepwalking in 11 of 18 cases. The trial outcome was in favor of the defendant in 14 of 18 cases. Defendants were relatively young males in all cases. Victims were usually adult relatives of the defendants in SRV cases and unrelated young girls or adolescents in SBS cases. In most cases the criminal events occurred 1-2 hours after the defendant's sleep onset, and both proximity and other potential triggering factors were reported. The forensic evaluations widely differed from case to case.

CONCLUSION

SRV and SBS medical-legal cases did not show apparent differences, except for the severity of the charges and the victim characteristics. An international multidisciplinary consensus for the forensic evaluation of SRV and SBS should be developed as an urgent priority.

Sexsomnia: an uncommon variety of parasomnia

Sexsomnia is considered a particular form of parasomnia characterized by atypical sexual behaviour during sleep. Only a few cases have been reported in the literature. We describe here two cases of sexsomnia that took place in adult women whose personal history was remarkable for traumatic sexual psychological stress during childhood. In addition, the first patient had a medical history of alcoholism during adolescence and current sleepwalking. In the second patient, drug consumption was reported during adolescence, and psychiatric assessment found a major depressive disorder. Neurological examination was normal for both patients. The sexual behaviour was reported by the bed partner because of total amnesia of the event by the patients. Events included moaning, vocalizations with dirty talk, masturbation, sexual assault, and sexual intercourse. The behaviour was harmful for the bed partner in the second case. For both patients, electroencephalogram and brain magnetic resonance imaging were normal whereas nocturnal polysomnography recordings revealed several abrupt and spontaneous arousals from slow-wave sleep. Patients were successfully treated by serotonin reuptake inhibitors. Our observations underline the fact that efforts need to be made to increase awareness of the issue of sexsomnia, in order to identify patients suffering from this atypical parasomnia, which can be associated with adverse psychological consequences and serious medico-legal issues.

Sexual behaviour in sleep: an internet survey

The objective of the study was to provide further information related to newly described parasomnia variant, Sexual Behaviour in Sleep (SBS, sexsomnia). Previous studies dealt with selected population, typically middle-aged males, featuring extensive medico-legal exposure. At the same time, an anecdotal evidence suggested higher involvement of younger population, and skew towards balance between genders comparable to those seen in other non-Rapid Eye Movement (NREM) sleep parasomnias. The epidemiological information regarding this condition is still virtually non-existent. In order to sample this difficult-to-reach population, a 28-item Internet survey was posted on the sexsomnia reference site and the link was also sent to prospective respondents (mostly registered visitors to this site). The respondents were able to complete the survey anonymously, which resulted in a need for the screening of bogus and duplicate results. At the end, a total of 219 validated responses were collected and analysed. The results showed greater representation of females (31% of the total number), and wider age distribution (mean age of 30.4 years). The respondents typically reported multiple sexsomnia episodes, in most cases precipitated by body contact, stress and fatigue. Relatively small number of respondents reported involvement of legal authorities (8.6% of males and 3% of females) and participation of minors in their sexsomnia (6% of the total sample). In spite of known limitations of such surveys, the study provided much needed insight into this complex nocturnal behaviour. It confirmed the anecdotal evidence about the gender and age distribution, and provided information on some key features, such as precipitating factors, type of behaviour, medication use, personal medical history and medico-legal aspects.

Sexsomnia: abnormal sexual behavior during sleep

This review attempts to assemble the characteristics of a distinct variant of sleepwalking called sexsomnia/sleepsex from the seemingly scarce literature into a coherent theoretical framework. Common features of sexsomnia include sexual arousal with autonomic activation (e.g. nocturnal erection, vaginal lubrication, nocturnal emission, dream orgasms). Somnambulistic sexual behavior and its clinical implications, the role of precipitating factors, diagnostic, treatment, and medico-legal issues are also reviewed. The characteristics of several individuals described in literature including their family/personal history of parasomnia as well as the abnormal behaviors occurring during sleep are reported.

Somnambulistic sexual behaviour (sexsomnia)

Somnambulism or sleepwalking is a viable defence on the basis of automatism. The behaviours that occur during sleepwalking can be highly complex and include sexual behaviour of all types. Somnambulistic sexual behaviour (also called sexsomnia, sleep sex) is considered a variant of sleepwalking disorder as the overwhelming majority of people with Sexsomnia have a history of parasomnia and a family history of sleepwalking. Sexual behaviour during a sleep automatism can vary from explicit sexual vocalisations, to violent masturbation, to complex sexual acts including anal, oral and vaginal penetration. A recent case in England is reported where the defendant was acquitted on 3 charges of rape on the basis of automatism due to somnambulistic sexual behaviour.

Non-rapid eye movement sleep parasomnias

Parasomnias are unpleasant or undesirable behavioral or experiential phenomena that occur during sleep. Once believed unitary phenomena related to psychiatric disorders, it is now clear that parasomnias result from several different phenomena and usually are not related to psychiatric conditions. Parasomnias are categorized as primary (disorders of the sleep states) and secondary (disorders of other organ systems that manifest themselves during sleep). Primary sleep parasomnias can be classified according to the sleep state of origin: rapid eye movement sleep, non-rapid eye movement sleep, and miscellaneous (those not respecting sleep state). Secondary sleep parasomnias are classified by the organ system involved.

Sexsomnia--a new parasomnia?

OBJECTIVE

To describe a distinct parasomnia involving sexual behaviour, which we have named sexsomnia.

METHOD

We have used a case series as a basis for the description of sexsomina.

RESULTS

Eleven patients with distinct behaviours of the sexual nature during sleep are described. The features in common with other nonrapid eye movement arousal parasomnias, such as sleepwalking are documented. Some patients had simply been referred to a tertiary sleep clinic for investigation of unrelated sleep problems. A small number had been involved in medicolegal issues. Sexsomnia has some distinct features that separate it from sleepwalking. The automatic arousal is more prominent, motor activities are relatively restricted and specific, and some form of dream mentation is often present.

CONCLUSIONS

A significant number of patients with this unusual parasomnia behaviour were identified only after specific questions were asked, suggesting that the behaviour is more common than previously thought.

Parasomnias: sleepwalking and the law

A recent, well-publicized case in which murder during sleepwalking was offered as a defense, underscores the fact that sleep medicine specialists are asked to render opinions or judgements regarding culpability in legal cases regarding violence claimed to have arisen from sleepwalking episodes. This review addresses this difficult issue from scientific, clinical and legal aspects, with emphasis upon the need for further research, calling for close collaboration between the legal and medical (both clinical and basic science) professions.

Medical-legal aspects of sleep medicine

Sleepiness and sleep disorders are increasingly raising interesting and important medical-legal issues in three areas: violent or injurious behavior arising from the sleep period, accidents or errors in judgment caused by sleepiness behind the wheel or in the workplace, and disability determinations caused by sleepiness-induced work impairment. Sleep-related violence may be caused by many conditions, most of which are diagnosable and treatable. Legal issues raised by these behaviors are usually enigmatic. The nature of such behaviors may be extremely complex, and documenting that a given violent act was caused by such a behavior, after the fact, may be difficult. Guidelines for the medical-legal evaluation of such behaviors have been developed and are evolving. Culpability determination in sleepiness-related industrial or motor vehicle accidents is in the developmental stage, and varies by jurisdiction. Disability determination for workplace sleepiness caused by sleep disorders is in its infancy, and poses a challenge, given the erroneous but pervasive societal attitude that sleepiness is a manifestation of laziness, depression, sloth, work-avoidance behavior, or a defect of character.

Myxoedematous madness and grievous bodily harm

Psychosis is a rare but recognized complication of hypothyroidism (otherwise known as 'myxoedematous madness'). This is the report of a man charged with attempted murder who was found to be suffering from myxoedematous madness. The case illustrates several problems in the law relating to mental disorder and criminal responsibility. He was interviewed in the absence of an appropriate adult and this led to the inadmissibility of the police interviews. However, to have laid the basis for a defence of insanity the ideal evidence would have been what he told the investigating police officers about his state of mind at the material time, under caution and possibly with the assistance of an appropriate adult. As it was, although he was clearly mentally ill at the material time, the insanity defence was not open to him as he did not satisfy the MacNaughton Rules and his mental state did not fulfill the criteria for automatism. By the time he stood trial he was fully recovered from his psychosis and this faced the judge with a difficulty in sentencing him. The case is used to discuss proposed changes to the law concerning insanity.