Dawn simulation and bright light in the treatment of SAD: a controlled study

Avery, David H; Eder, Derek N; Bolte, Mary Ann; Hellekson, Carla J; Dunner, David L; Vitiello, Michael V; Prinz, Pat N

« Previous Next »Biological Psychiatry
Volume 50, Issue 3 , Pages 205-216, 1 August 2001

Dawn simulation and bright light in the treatment of SAD: a controlled study

David H Avery
- Department of Psychiatry and Behavioral Sciences (DHA, MAB, CJH, DLD, MVV, PNP), University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington, USA
- Address reprint requests to: David H. Avery, M.D., University of Washington School of Medicine, Department of Psychiatry & Behavioral Sciences, Harborview Medical Center, Box 359896, 325 Ninth Avenue, Seattle WA 98104-2499
Derek N Eder
- Göteborg University Institute of Clinical Neuroscience (DNE), Section of Psychiatry, Sahlgrenska University Hospital, Göteborg, Sweden
Mary Ann Bolte
- Department of Psychiatry and Behavioral Sciences (DHA, MAB, CJH, DLD, MVV, PNP), University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington, USA
Carla J Hellekson
- Department of Psychiatry and Behavioral Sciences (DHA, MAB, CJH, DLD, MVV, PNP), University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington, USA
David L Dunner
- Department of Psychiatry and Behavioral Sciences (DHA, MAB, CJH, DLD, MVV, PNP), University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington, USA
Michael V Vitiello
- Department of Psychiatry and Behavioral Sciences (DHA, MAB, CJH, DLD, MVV, PNP), University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington, USA
Pat N Prinz
- Department of Psychiatry and Behavioral Sciences (DHA, MAB, CJH, DLD, MVV, PNP), University of Washington School of Medicine, Harborview Medical Center, Seattle, Washington, USA

Received 29 December 2000; received in revised form 11 May 2001; accepted 16 May 2001.

Abstract

Background: Some small controlled studies have found that dawn simulation is effective in treating seasonal affective disorder (SAD). With a larger sample size and a longer duration of treatment, we compared dawn simulation with bright light therapy and a placebo condition in patients with SAD.

Method: Medication-free patients with SAD were randomly assigned to one of three conditions: bright light therapy (10,000 lux for 30 min, from 6:00 am to 6:30 am), dawn simulation (1.5 hour dawn signal from 4:30 am to 6:00 am peaking at 250 lux), and a placebo condition, a dim red light (1.5 hour dawn signal from 4:30 am to 6:00 am peaking at 0.5 lux.) Over the subsequent 6 weeks, the subjects were blindly rated by a psychiatrist using the Structured Interview Guide for the Hamilton Depression Rating-Seasonal Affective Disorder Version (SIGH-SAD). We modeled the profiles of the remissions (SIGH-SAD ≤ 8) and response (≥50% decrease in SIGH-SAD) to treatment over time using Cox proportional hazards models.

Results: The sample consisted of 95 subjects who were randomized to the three conditions: bright light (n = 33), dawn simulation (n = 31) and placebo (n = 31). Dawn simulation was associated with greater remission (p < .05) and response (p < .001) rates compared to the placebo. Bright light did not differ significantly from the placebo. Dawn simulation was associated with greater remission (p < .01) and response (p < .001) rates compared to the bright light therapy. The mean daily hours of sunshine during the week before each visit were associated with a significant increase in likelihood of both remission (p < .001) and response (p < .001).

Conclusions: Dawn simulation was associated with greater remission and response rates compared to the placebo and compared to bright light therapy. The hours of sunshine during the week before each assessment were associated with a positive clinical response.

Keywords: Seasonal affective disorder, winter depression, light therapy, phototherapy, dawn simulation, efficacy