[The incubus phenomenon: A sleep-related condition, not to be confused with psychosis]. / Het incubusfenomeen: een slaapgerelateerde stoornis, niet te verwarren met psychose.

ABSTRACT

BACKGROUND: The incubus phenomenon is a paroxysmal condition characterised by sleep paralysis coinciding with a sensed presence and the frightening sensation that something or somebody is exerting pressure on the thorax. AIM: To present an overview of the literature on the incubus phenomenon and to provide practical advice regarding diagnosis and treatment. METHOD: To obtain information for our paper we carried out a search in PubMed and the historical literature. RESULTS: The incubus phenomenon is a relatively unknown condition, even though, world-wide, it has a lifetime prevalence rate of 30% in the general population. The prevalence is even higher among students, psychiatric patients and patients with narcolepsy. It is attributed to a dissociation of the rem sleep phase and the subsequent intrusion of endogenously mediated percepts. The condition rarely requires treatment because it is self-limiting, and generally occurs only once in a lifetime. Repeated attacks, however, may warrant additional diagnostic testing with the aid of polysomnography and may require treatment with anxiolytics, antidepressants, anticholinergics or anti-epileptics. CONCLUSION: The incubus phenomenon is an intrusive condition, but, as far as we currently know, it is benign. Nevertheless, it is important that the condition is recognised and not confused with a psychotic disorder or any other type of severe mental illness. When necessary, it should be treated lege artis.