title: [Sleep disturbances in schizophrenia].
abstract: BACKGROUND
  Schizophrenia is often related with sleep disorders. In clinical practice insomnia is a common feature in schizophrenia. Difficulty falling asleep, maintaining or achieving a restful sleep is associated with symptoms severity and has been listed as a prodromal symptom of psychotic relapse. Sleep disturbances in schizophrenia may arise during the acute phase of illness and persists in many cases in chronic phase.
  
  
  OBJECTIVE
  The authors intend to review the main sleep disturbances observed in schizophrenia, the possible pathophysiological mechanisms, their clinical impact, and the effects of antipsychotic medication on sleep architecture.
  
  
  METHODS
  This study was carried out a systematic search of published literature from January 1965 to May 2010, through PubMed, using the following key words: sleep, REM sleep, NREM sleep, schizophrenia, polysomnography, actigraphy and antipsychotics.
  
  
  RESULTS
  Most changes found in objective studies using the polysomnography, in patients with schizophrenia are: reduction of total sleep time, decrease in slow wave sleep, REM latency and sleep efficiency. Studies using actigraphy also reveal that these patients experience changes in circadian rhythm sleep disorders, specifically the irregular type and phase advance. Although some sleep disorders improve with antipsychotic treatment, in many cases, even during the remission of the disease, sleep continues fragmented , suggesting that there are physiopathologic mechanisms involved in sleep disturbance in these patients.
  
  
  CONCLUSIONS
  Privation of adequate and restful sleep has a negative impact on rehabilitation strategies, quality of life of patients with schizophrenia, and may contribute to worsening of cognitive deficits.
authors.affiliation: Centro Hospitalar Psiquiátrico de Lisboa, Lisboa, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Afonso
authors.forename: Vânia
authors.initials: V
authors.lastname: Viveiros
authors.forename: Tiago
authors.initials: T
authors.lastname: Vinhas de Sousa
mesh_terms: D006801:Humans; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology; D012893:Sleep Wake Disorders / Q000209:etiology*