title: Isolated sleep paralysis and hypnic hallucinations in schizophrenia.
abstract: BACKGROUND
  Usually remembered in the context of Narcolepsy-Cataplexy syndrome, isolated sleep paralysis (SP) and hypnic hallucination are widely prevalent and because of the overlap of symptoms with schizophrenia, their identification is important but unrecognized.
  
  
  OBJECTIVE
  To determine the presence of SP and hypnic hallucinations (HH) in people with schizophrenia and schizoaffective disorder.
  
  
  METHODS
  Cross-sectional survey.
  
  
  METHODS
  Participants were patients receiving follow-up care for schizophrenia from Assertive Community Treatment Team. A screening questionnaire was administered during their routine follow-up visits.
  
  
  RESULTS
  Of 71 respondents (49 males, 22 females) only 11 (10 males and 1 female), that is, 15% reported SP, and 12 (7 males and 5 females), that is, 16.9% reported HH, a considerably low prevalence.
  
  
  CONCLUSIONS
  It is difficult to study the presence of SP and HH in patients with active or residual symptoms of schizophrenia, and more refined studies and appropriate questionnaires are required. The possibility of SP and HH confounding or being misdiagnosed as psychotic symptoms needs to be borne in mind.
authors.affiliation: Department of Psychiatry, Regional Mental Health Care, University of Western Ontario, London, Ontario, Canada.
authors.forename: Prakash
authors.initials: P
authors.lastname: Gangdev
authors.affiliation: Department of Psychiatry, Regional Mental Health Care, University of Western Ontario, London, Ontario, Canada.
authors.forename: Varinder
authors.initials: V
authors.lastname: Dua
authors.affiliation: Department of Psychiatry, Regional Mental Health Care, University of Western Ontario, London, Ontario, Canada.
authors.forename: Nina
authors.initials: N
authors.lastname: Desjardins
keywords: Hypnic hallucinations; schizophrenia; sleep paralysis
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