title: Exploring the presence of narcolepsy in patients with schizophrenia.
abstract: There are several case reports of patients with narcolepsy and schizophrenia, but a systematic examination of the association of both disorders has not been done. The aim of this work is to assess the frequency of narcolepsy with cataplexy in a large consecutive series of adult patients with schizophrenia and schizoaffective disorder.
  
  
  
  We screened 366 consecutive patients with schizophrenia or schizoaffective disorder with a sleep questionnaire and the Epworth Sleepines scale (ESS) exploring narcoleptiform symptoms. Those who screened positive were assessed by a sleep specialist, and offered an HLA determination. CSF hypocretin-1 determination was proposed to those who were HLA DQB1*06:02 positive.
  
  
  
  On the screening questionnaire, 17 patients had an ESS score ≥11 without cataplexy, 15 had cataplexy-like symptoms with an ESS score < 11, and four had an ESS score ≥11 plus cataplexy-like symptoms. Of those, 24 patients were evaluated by a sleep specialist. Five of these 24 were HLA DQB1*06:02 positive, and three of these five subjects underwent lumbar puncture showing normal hypocretin-1 levels.
  
  
  
  Our results suggest that narcolepsy with cataplexy is not an unrecognized disease in adult patients with schizophrenia or schizoaffective disorder.
authors.affiliation: Neurology Service and Multidisciplinary Sleep Disorders Unit, Hospital Parc Taulí, Sabadell, Spain. gsansa@tauli.cat.
authors.forename: Gemma
authors.initials: G
authors.lastname: Sansa
authors.affiliation: Neuropsychology Department, Neurology Service. Hospital Parc Taulí, Sabadell, Spain.
authors.forename: Alba
authors.initials: A
authors.lastname: Gavaldà
authors.affiliation: Neurology Service and Multidisciplinary Sleep Disorders Unit, Hospital Clínic of Barcelona, Barcelona, Spain.
authors.forename: Carles
authors.initials: C
authors.lastname: Gaig
authors.affiliation: Psychiatry Service, Hospital Parc Taulí, Sabadell, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Monreal
authors.affiliation: Immunology Laboratory, Hospital Clínic of Barcelona, Barcelona, Spain.
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Ercilla
authors.affiliation: Biochemistry and Molecular Genetics Laboratory, Centre de Diagnòstic Biomèdic (CDB), Hospital Clínic of Barcelona, Barcelona, Spain.
authors.forename: Roser
authors.initials: R
authors.lastname: Casamitjana
authors.affiliation: Neurology Service and Multidisciplinary Sleep Disorders Unit, Hospital Parc Taulí, Sabadell, Spain.
authors.forename: Gisela
authors.initials: G
authors.lastname: Ribera
authors.affiliation: Neurology Service and Multidisciplinary Sleep Disorders Unit, Hospital Clínic of Barcelona, Barcelona, Spain.
authors.forename: Alex
authors.initials: A
authors.lastname: Iranzo
authors.affiliation: Neurology Service and Multidisciplinary Sleep Disorders Unit, Hospital Clínic of Barcelona, Barcelona, Spain.
authors.forename: Joan
authors.initials: J
authors.lastname: Santamaria
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000175:diagnosis / Q000453:epidemiology*; D012559:Schizophrenia / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Hallucinations; Hypocretin; Narcolepsy; Psychotic disorders; Schizophrenia