title: Sleep and circadian rhythms in mood disorders.
abstract: OBJECTIVE
  Self-reported sleep disturbances are present in over 80% of patients with depression. However, sleep electroencephalography (EEG) findings, based on overnight polysomnography have not always differentiated depressed patients from healthy individuals.
  
  
  METHODS
  The present paper will review the findings on sleep EEG studies in depression highlighting how recent technological and methodological advances have impacted on study outcomes.
  
  
  RESULTS
  The majority of studies, including our own work, do indicate that sleep homeostasis and sleep EEG rhythms are abnormal in depression, but the sleep disturbances were strongly moderated by gender and age. Melancholic features of depression correlated significantly with low slow-wave activity in depressed men, but not in depressed women. Women with depression showed low temporal coherence of sleep EEG rhythms but the presence or absence of melancholic features did not influence correlations.
  
  
  CONCLUSIONS
  Diagnostic classification schemas and clinical features of depression may influence sleep EEG findings, but gender may be a more important consideration.
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor 48105, USA. rosearmi@med.umich.edu
authors.forename: R
authors.initials: R
authors.lastname: Armitage
mesh_terms: D021081:Chronobiology Disorders / Q000453:epidemiology*; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004569:Electroencephalography; D005260:Female; D006801:Humans; D012890:Sleep / Q000502:physiology*; D012894:Sleep Stages / Q000502:physiology