Prevalence Rates of the Incubus Phenomenon: A Systematic Review and Meta-Analysis

Abstract

BackgroundThe incubus phenomenon is a paroxysmal sleep-related disorder characterized by compound hallucinations experienced during brief phases of (apparent) wakefulness. The condition has an almost stereotypical presentation, characterized by a hallucinated being that exerts pressure on the thorax, meanwhile carrying out aggressive and/or sexual acts. It tends to be accompanied by sleep paralysis, anxiety, vegetative symptoms, and feelings of suffocation. Its prevalence rate is unknown since, in prior analyses, cases of recurrent isolated sleep paralysis with/without an incubus phenomenon have been pooled together. This is unfortunate, since the incubus phenomenon has a much greater clinical relevance than isolated sleep paralysis.MethodsPubMed, Embase, and PsycINFO were searched for prevalence studies of the incubus phenomenon, and a meta-analysis was performed.ResultsOf the 1,437 unique records, 13 met the inclusion criteria, reporting on 14 (k) independent prevalence estimates (total N = 6,079). The pooled lifetime prevalence rate of the incubus phenomenon was 0.19 [95% confidence interval (CI) = 0.14–0.25, k = 14, N = 6,079] with heterogeneous estimates over different samples. In selected samples (e.g., patients with a psychiatric disorder, refugees, and students), prevalence rates were nearly four times higher (0.41, 95% CI = 0.25–0.56, k = 4, n = 1,275) than in the random samples (0.11, 95% CI = 0.08–0.14, k = 10, n = 4,804). This difference was significant (P < 0.001).ConclusionThis review and meta-analysis yielded a lifetime prevalence of the incubus phenomenon in the general population of 0.11 and, in selected samples, of 0.41. This is slightly higher than the prevalence rates in previous analyses that included cases of recurrent isolated sleep paralysis without an incubus phenomenon. Based on the condition’s robust clinical presentation and the relatively high prevalence rates, we advocate inclusion of the incubus phenomenon as a diagnostic category in major classifications such as the International Classification of Diseases and Related Health Problems and the Diagnostic and Statistical Manual of Mental Disorders. Recommendations are also made for clinical practice and future research.

The prevalence of sleep paralysis in medical students in Buenos Aires, Argentina

“…This phenomenon can lead to insomnia, comorbid anxiety, or comorbid delusional disorder but should not be confused with schizophrenia. The prevalence of this phenomenon in the general population is 19%, [20] slightly higher than that found in this study (14.9%). According to mythological beliefs, an Incubus is a demon that lies down on women engaging in sexual activity with them.…”

Measuring Counterintuitiveness in Supernatural Agent Dream Imagery

“…Importantly, supernatural agent imagery is a common feature of extreme forms of terrifying nightmares manifested in sleep paralysis, incubus dreams, horrifying lucid dreams, and psychiatric disorders such as nocturnal panic attacks, all of which frequently arise during REM sleep (e.g., Nordin, 2011; McNamara et al, 2018). Even though these parasomnias may, like narcolepsy, be considered as sleep disorders in their own right, they are characteristically observed in a variety of psychiatric disorders, such as major depressive disorder, anxiety, post-traumatic stress disorder, attention-deficit/hyperactivity disorder, schizophrenia, bipolar disorder, borderline personality disorder, and other psychopathological conditions such as substance abuse (e.g., Kirov and Brand, 2014; de Sá and Mota-Rolim, 2016; Molendijk et al, 2017; McNamara et al, 2018; Tempesta et al, 2018; Baird et al, 2019).…”

Relationships between sleep paralysis and sleep quality: current insights

“… 18 In a meta-analysis focusing specifically on incubus experiences, a lifetime prevalence of 11% was found. 19 A large number of variables have been associated with sleep paralysis. 20 In particular, sleep paralysis is more common in student and psychiatric samples.…”