title: Increased prevalence of sleep disorders in chronic headache: a case-control study.
abstract: OBJECTIVE
  The aim of our study was to investigate the prevalence of sleep disorders in chronic headache patients and to evaluate the role of psychiatric comorbidity in the association between chronic headache and sleep complaints.
  
  
  BACKGROUND
  The prevalence of sleep disorders in chronic headache has been seldom investigated, although from the earliest description chronic headache has been associated with sleep disturbances. On the contrary, mood disorders are commonly associated with both sleep disturbances and chronic headache--each of which are, in turn, core features of mood disorders. Therefore, it may be important to discriminate between sleep problems that can be attributed to a comorbid psychiatric disorder, and those specifically associated with headache. Only a few studies investigating the association of chronic headache with sleep difficulties have also taken into account to consider the possible role of anxiety and depression.
  
  
  METHODS
  A total of 105 consecutive patients with daily or nearly daily headache and 102 patients with episodic headache, matched by age, sex, and type of headache at onset, underwent a structured direct interview about their sleep habits and psychiatric diseases.
  
  
  RESULTS
  In total, 80 out of 105 patients with chronic headache received a diagnosis of medication overuse headache, 21 patients were classified as chronic migraine and 4 as chronic tension-type headache without drug overuse.
  
  
  METHODS
  Patients with chronic headache showed a high prevalence of insomnia, daytime sleepiness, and snoring with respect to controls (67.7% vs 39.2%, 36.2% vs 23.5%, and 48.6% vs 37.2%, respectively). Forty-five patients with chronic headache (42.9%) had psychiatric comorbidity (anxiety and/or depressive disorders), vs 27 episodic headache patients (26.5%). Multivariate analysis disclosed that low educational level, lower mean age at headache onset, and insomnia are independently associated with chronic headache.
  
  
  CONCLUSIONS
  Patients with chronic headache had a high prevalence of sleep complaints. Insomnia may thus represent an independent risk factor for headache chronification. Recognition of sleep disorders, alone or in association with depression or anxiety, may be useful in episodic headache patients to prevent chronification.
authors.affiliation: Department of Neurological Sciences, University of Bologna, via Ugo Foscolo 7, Bologna, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Sancisi
authors.forename: Sabina
authors.initials: S
authors.lastname: Cevoli
authors.forename: Luca
authors.initials: L
authors.lastname: Vignatelli
authors.forename: Marianna
authors.initials: M
authors.lastname: Nicodemo
authors.forename: Giulia
authors.initials: G
authors.lastname: Pierangeli
authors.forename: Stefano
authors.initials: S
authors.lastname: Zanigni
authors.forename: Daniela
authors.initials: D
authors.lastname: Grimaldi
authors.forename: Pietro
authors.initials: P
authors.lastname: Cortelli
authors.forename: Pasquale
authors.initials: P
authors.lastname: Montagna
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002649:Child Abuse / Q000175:diagnosis / Q000523:psychology; D015897:Comorbidity; D005260:Female; D020773:Headache Disorders / Q000150:complications* / Q000453:epidemiology* / Q000523:psychology; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000150:complications* / Q000453:epidemiology* / Q000523:psychology