title: Circadian temperature and cortisol rhythms during a constant routine are phase-delayed in hypersomnic winter depression.
abstract: Circadian temperature, cortisol, and thyroid-stimulating hormone (TSH) rhythms during a constant routine were assessed in 6 female controls and 6 female patients with hypersomnic winter depression (seasonal affective disorder, SAD) before and after morning bright light treatment. After sleep was standardized for 6 days, the subjects were sleep-deprived and at bed rest for 27 hours while rectal temperature, cortisol, and TSH levels were assessed. The minimum of the fitted rectal temperature rhythm was phase-delayed in the SAD group compared to the controls 5:42 AM vs. 3:16 AM (p < .005); with bright light treatment, the minimum advanced from 5:42 AM to 3:36 AM (p = .06). The minimum of the cortisol rhythm was phase-delayed in the SAD group compared to the control group, 12:11 AM vs. 10:03 PM (P < .05); with bright light treatment, the minimum advanced from 12:11 AM to 10:38 PM (P = .06) [corrected]. The acrophase of the TSH rhythm was not significantly phase-delayed in SAD subjects compared to control, though the trend appeared to be toward a phase-delay (p = .07). After bright light therapy, the TSH acrophase was not significantly different in the SAD subjects; the trend was a phase-advance (p = .09). Overall, the data suggest that circadian rhythms are phase-delayed relative to sleep in SAD patients and that morning bright light phase-advances those rhythms.
authors.affiliation: Department of Psychiatry, Harborview Medical Center, Seattle, Washington, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Avery
authors.forename: K
authors.initials: K
authors.lastname: Dahl
authors.forename: M V
authors.initials: MV
authors.lastname: Savage
authors.forename: G L
authors.initials: GL
authors.lastname: Brengelmann
authors.forename: L H
authors.initials: LH
authors.lastname: Larsen
authors.forename: M A
authors.initials: MA
authors.lastname: Kenny
authors.forename: D N
authors.initials: DN
authors.lastname: Eder
authors.forename: M V
authors.initials: MV
authors.lastname: Vitiello
authors.forename: P N
authors.initials: PN
authors.lastname: Prinz
mesh_terms: D000328:Adult; D001831:Body Temperature; D002940:Circadian Rhythm; D006970:Disorders of Excessive Somnolence / Q000150:complications*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008597:Menstrual Cycle; D010789:Phototherapy; D011863:Radioimmunoassay; D016574:Seasonal Affective Disorder / Q000150:complications* / Q000628:therapy; D013972:Thyrotropin / Q000097:blood; D013997:Time Factors
chemical_list: D013972:Thyrotropin; D006854:Hydrocortisone