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.