OBJECTIVE: We tested the hypothesis that phase-delayed circadian rhythms underlie seasonal affective disorder (SAD) by measuring phase position of 6-sulfatoxymelatonin excretion and comparing antidepressant response to morning or evening light given as a first treatment. DESIGN: Randomized controlled trial. SETTING: Ambulatory. PATIENTS: Thirty-two women and seven men with SAD. INTERVENTION: Light therapy (2500 lux for 1 hour for 1 week) was administered either at 7 AM or 10 PM, preceded by a baseline week and followed by a withdrawal week. RESULTS: Our SAD patient sample was moderately depressed (Hamilton Depression Scale [HAM-D] score 18); a HAM-D reduction of 50% or more was found in 12 of 18 patients given morning and in 15 of 21 patients given evening light (70% response rate). Response was not dependent on age, gender, stage of the menstrual cycle, time of year, or on the timing or duration of sleep. Urinary 6-sulfatoxymelatonin was measured in 30 patients; 22 had phase-delayed circadian rhythms. However, phase position was correlated neither with depth of depression nor with a preferential response to morning or evening light. COMMENT: Both morning and evening light therapy improved depressive symptoms in patients with SAD independent of their circadian phase or sleep timing. These findings argue against a circadian phase-delay hypothesis of the pathophysiology of SAD, or the necessity of a phase-advance by morning light for clinical efficacy. They additionally suggest more practicable and flexible schedules for light therapy in SAD, since time of day is not crucial.
RCT Entities:
OBJECTIVE: We tested the hypothesis that phase-delayed circadian rhythms underlie seasonal affective disorder (SAD) by measuring phase position of 6-sulfatoxymelatonin excretion and comparing antidepressant response to morning or evening light given as a first treatment. DESIGN: Randomized controlled trial. SETTING: Ambulatory. PATIENTS: Thirty-two women and seven men with SAD. INTERVENTION: Light therapy (2500 lux for 1 hour for 1 week) was administered either at 7 AM or 10 PM, preceded by a baseline week and followed by a withdrawal week. RESULTS: Our SADpatient sample was moderately depressed (Hamilton Depression Scale [HAM-D] score 18); a HAM-D reduction of 50% or more was found in 12 of 18 patients given morning and in 15 of 21 patients given evening light (70% response rate). Response was not dependent on age, gender, stage of the menstrual cycle, time of year, or on the timing or duration of sleep. Urinary 6-sulfatoxymelatonin was measured in 30 patients; 22 had phase-delayed circadian rhythms. However, phase position was correlated neither with depth of depression nor with a preferential response to morning or evening light. COMMENT: Both morning and evening light therapy improved depressive symptoms in patients with SAD independent of their circadian phase or sleep timing. These findings argue against a circadian phase-delay hypothesis of the pathophysiology of SAD, or the necessity of a phase-advance by morning light for clinical efficacy. They additionally suggest more practicable and flexible schedules for light therapy in SAD, since time of day is not crucial.
Authors: Charles J Meliska; Luis F Martínez; Ana M López; Diane L Sorenson; Sara Nowakowski; Daniel F Kripke; Jeffrey Elliott; Barbara L Parry Journal: Chronobiol Int Date: 2013-09-03 Impact factor: 2.877
Authors: J L Anderson; M A St Hilaire; R R Auger; C A Glod; S J Crow; A N Rivera; S M Fuentes Salgado; S J Pullen; T K Kaufman; A J Selby; D J Wolfe Journal: Chronobiol Int Date: 2016-08-05 Impact factor: 2.877
Authors: Uttam K Raheja; Sarah H Stephens; Braxton D Mitchell; Kelly J Rohan; Dipika Vaswani; Theodora G Balis; Gagan V Nijjar; Aamar Sleemi; Toni I Pollin; Kathleen Ryan; Gloria M Reeves; Nancy Weitzel; Mary Morrissey; Hassaan Yousufi; Patricia Langenberg; Alan R Shuldiner; Teodor T Postolache Journal: J Affect Disord Date: 2012-11-17 Impact factor: 4.839