title: Antidepressant action of melatonin in the treatment of Delayed Sleep Phase Syndrome.
abstract: BACKGROUND
  Depression is a common problem in patients with Delayed Sleep Phase Syndrome (DSPS). This study used a randomized, double-blind, crossover, placebo-controlled approach to test the hypothesis that exogenous melatonin (5mg) can attenuate depressive symptomatology in DSPS patients.
  
  
  METHODS
  Twenty patients with an established diagnosis of DSPS were dichotomized into DSPS with depressive symptoms (Group I; n=8) and without depressive symptoms (Group II; n=12) based on structured clinical interviews and a score greater than 17 on Center for Epidemiologic Studies Depression Scale (CES-D). Both groups received melatonin and placebo treatment for 4 weeks with a 1-week washout period in between. Participants underwent a clinical interview and psychometric evaluation to assess depression, and overnight polysomnographic sleep studies were carried out at baseline and at the end of melatonin and placebo treatments. Furthermore, melatonin secretion rhythm as a circadian phase marker was assessed by measuring urinary 6-sulphatoxymelatonin levels.
  
  
  RESULTS
  Melatonin treatment significantly reduced depression scores in the depressed patients as measured by the CES-D and Hamilton Depression Rating Scale--17. Melatonin treatment improved sleep continuity in both groups compared to placebo and baseline conditions. Group I individuals showed marked alterations in melatonin rhythms compared to Group II individuals.
  
  
  CONCLUSIONS
  Exogenous melatonin treatment may be an effective treatment modality for individuals with circadian rhythm sleep disorders and associated comorbid depressive symptomatology.
authors.affiliation: Sleep Research Laboratory, University Health Network, Toronto, Ont., Canada.
authors.forename: Shadab A
authors.initials: SA
authors.lastname: Rahman
authors.forename: Leonid
authors.initials: L
authors.lastname: Kayumov
authors.forename: Colin M
authors.initials: CM
authors.lastname: Shapiro
mesh_terms: D000328:Adult; D002492:Central Nervous System Depressants / Q000627:therapeutic use*; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology; D018592:Cross-Over Studies; D003863:Depression / Q000188:drug therapy* / Q000209:etiology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives / Q000627:therapeutic use* / Q000652:urine; D011569:Psychiatric Status Rating Scales; D012890:Sleep / Q000187:drug effects / Q000502:physiology; D020178:Sleep Disorders, Circadian Rhythm / Q000150:complications / Q000188:drug therapy* / Q000523:psychology
chemical_list: D002492:Central Nervous System Depressants; C054513:6-sulfatoxymelatonin; D008550:Melatonin