Dawn simulation compared with a dim red signal in the treatment of winter depression

Biol Psychiatry. 1994 Aug 1;36(3):180-8. doi: 10.1016/0006-3223(94)91223-8.


In a randomized, parallel design, 19 patients with winter depression were treated with either a week of a white 1.5-hr dawn simulation peaking at 250 lux or a week of a red, 1.5-hr dawn signal peaking at 2 lux. The subjects were told that they would receive either a white or red dawn reaching in intensity that would be dimmer than standard bright light treatment. At the end of both the baseline week and the treatment week subjects were blindly assessed with the Hamilton Rating Scale for Depression (HDRS). Analysis of covariance was used to compare the two dawn treatments. The white, 1.5-hr, 250 lux dawn simulation resulted in significantly (p < 0.05) lower HDRS scores compared to the red, 1.5-hr, 2 lux dawn. This is the second controlled study which indicates that dawn simulation is an effective treatment for winter depression.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Circadian Rhythm
  • Female
  • Humans
  • Male
  • Middle Aged
  • Personality Inventory
  • Phototherapy / methods*
  • Seasonal Affective Disorder / psychology
  • Seasonal Affective Disorder / therapy*
  • Sleep Stages