title: Effects of light on low nocturnal bilirubin in winter depression: a preliminary report.
abstract: BACKGROUND
  The light-absorbing pigments involved in the induction of treatment of winter depression are unknown. It has been proposed that circulating bilirubin serves as a photoreceptor, in part because of its similarity to the chromophore of phytochrome, a primary time-setting plant molecule.
  
  
  METHODS
  We measured nocturnal bilirubin levels in nine patients with winter depression, and seven age- and gender-matched normal comparison volunteers.
  
  
  RESULTS
  Nocturnal bilirubin levels were lower in patients than in controls (p <.02), increased in both groups during the night (p <.0001), and increased in patients after 2 weeks of morning light treatment (p =.0009), which was accompanied by clinical improvement.
  
  
  CONCLUSIONS
  Low nocturnal bilirubin levels may be associated with winter seasonal depression.
authors.affiliation: VA Connecticut Healthcare System and Yale School of Medicine, Department of Psychiatry, West Haven, CT 06516, USA.
authors.forename: Dan A
authors.initials: DA
authors.lastname: Oren
authors.forename: Paul H
authors.initials: PH
authors.lastname: Desan
authors.forename: Nashaat
authors.initials: N
authors.lastname: Boutros
authors.forename: Amit
authors.initials: A
authors.lastname: Anand
authors.forename: Dennis S
authors.initials: DS
authors.lastname: Charney
mesh_terms: D000328:Adult; D001663:Bilirubin / Q000097:blood*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010789:Phototherapy; D016574:Seasonal Affective Disorder / Q000097:blood / Q000628:therapy*; D016896:Treatment Outcome
chemical_list: D001663:Bilirubin