Features of isolated sleep paralysis among Nigerians.

Background: There is paucity of studies on isolated sleep paralysis (ISP).

Objectives: To explore the relationship of variables for ISP sufferers, and clarify factors predictive of ISP health behaviour (IHB--doing something to prevent further attacks).

Design: Cross-sectional study.

Setting: General population. Measurement: 24-item ISP questionnaire completed by respondents. Subjects: One hundred and ten (38.2%m, aged 30.9 years).

Results: Mean ISP frequency in the lifetime, past year and past month, were respectively, 6.7, 2.02, and 0.5; average duration of episodes was four minutes, and 63.6% experienced it while awakening from sleep. Using ICSD criteria, 2.7% had severe experience (i.e. at least once per week), 18.2% moderately severe (once per month) and 75.5% mildly severe (less than once per month), with no significant demographic associations. 56.4% were afraid of the experience, 76.4% had little/no worries that something was seriously wrong with their bodies; 39.1% cited supernatural causes, 35.5% cited physiological/psychosocial causes; and 44.5% described a hallucinatory experience. 1.8% took medical measures, and 7.3% consulted a faith healer; 44.5% resorted to prayers and 41.8% did nothing to prevent further attacks. The primary determinant of IHB was being afraid of ISP.

Conclusion: These findings have public mental health education, treatment and research implications.