title: Sleep paralysis in adolescents: the 'a dead body climbed on top of me' phenomenon in Mexico.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the prevalence and characteristics of sleep paralysis in adolescents using a folk expression.
  
  
  METHODS
  Three hundred and twenty-two adolescents (mean age, 15.9 +/- 0.88 years; 66.8% female) from three high schools in Mexico City completed both a self-reported questionnaire, including a colloquial definition of sleep paralysis and the Epworth Sleepiness Scale.
  
  
  RESULTS
  A high proportion of the adolescents (92.5%) had heard about the 'a dead body climbed on top of me' expression and 27.6% of them had experienced the phenomenon. Sleep paralysis was present in 25.5% while the prevalence rate for hypnagogic/hypnopompic hallucinations was 22%; 61% had experienced >or=2 episodes in their lifetime. The mean age of onset was 12.5 +/- 3 years. Sleepiness scores for the subjects who had experienced at least one event were not significantly different from subjects who had not experienced any. In 72% of cases, the episodes were composed of both sleep paralysis and hallucinations while 20.2% consisted of only sleep paralysis and 7.8% of only hallucinations. The number and characteristics of events were not significantly different between adolescents with only one episode and those with two or more episodes.
  
  
  CONCLUSIONS
  The characteristics of the 'a dead body climbed on top of me' phenomenon suggest that is identical to sleep paralysis and a frequent experience among Mexican adolescents. During adolescence, sleep paralysis seems to be a recurrent phenomenon frequently accompanied by hallucinatory experiences.
authors.affiliation: Clinical Services, National Institute of Psychiatry Ramón de la Fuente Muñiz, México DF, México. jimalex@imp.edu.mx
authors.forename: Alejandro
authors.initials: A
authors.lastname: Jiménez-Genchi
authors.forename: Víctor M
authors.initials: VM
authors.lastname: Avila-Rodríguez
authors.forename: Frida
authors.initials: F
authors.lastname: Sánchez-Rojas
authors.forename: Blanca E Vargas
authors.initials: BE
authors.lastname: Terrez
authors.forename: Alejandro
authors.initials: A
authors.lastname: Nenclares-Portocarrero
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology; D017668:Age of Onset; D015897:Comorbidity; D005260:Female; D005495:Folklore; D006212:Hallucinations / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D015995:Prevalence; D020188:Sleep Paralysis / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D011795:Surveys and Questionnaires