Nocturnal hallucinations in ultra-orthodox Jewish Israeli men.

Hallucinations that occur predominantly at night are reported in 122 out of a sample of 302 ultra-orthodox Jewish Israeli men referred for psychiatric evaluation. Demographic data and the content of a semistructured interview in 302 ultra-orthodox Jewish young men seen over a 10-year period in Jerusalem were evaluated retrospectively by two researchers. Of the 302 subjects, 122 reported hallucinations predominantly at night, 23 reported hallucinations with no diurnal variation, and 157 did not report hallucinations. Most of those with nocturnal hallucinations were in their late teens, were seen only once or twice, were brought in order to receive an evaluation letter for the Army, and had a reported history of serious learning difficulties. The nocturnal hallucinatory experiences were predominantly visual, and the images were frightening figures from daily life or from folklore. Many of the subjects were withdrawn, monosyllabic, reluctant interviewees. Ultra-orthodox Jewish beliefs include a belief in demons, particularly of dead souls, who visit at night. This cultural group's value on study at Yeshivas away from home places significant pressure on teenage boys with mild or definite subnormality, possibly precipitating the phenomenon at this age in this sex. Although malingering had to be considered as a possible explanation in many cases owing to the circumstances of the evaluation, short-term and long-term follow-up on a limited sample allowed this explanation to be dismissed in a significant number of cases. We suggest therefore that nocturnal hallucinations are a culture-specific phenomenon.