title: The treatment of early-morning awakening insomnia with 2 evenings of bright light.
abstract: OBJECTIVE
  To assess the effectiveness of brief bright-light therapy for the treatment of early-morning awakening insomnia.
  
  
  METHODS
  Twenty-four healthy adults with early-morning awakening insomnia were assigned to either the bright-light condition (2,500-lux white light) or the control (dim red light) condition.
  
  
  RESULTS
  The circadian phase of rectal temperature and urinary melatonin rhythms were assessed with 26-hour constant routines before and after 2 evenings of light therapy. Sleep and daytime functioning were monitored using sleep diaries, activity monitors, and mood scales before light therapy and for 4 weeks during the follow-up period. While there were no significant circadian phase changes in the dim-light control group, the bright-light group had significant 2-hour phase delays of circadian temperature and melatonin rhythm. Compared to pretreatment measures, over the 4-week follow-up period, the bright-light group had a greater reduction of time awake after sleep onset, showed a trend toward waking later, and had a greater increase of total sleep time. Participants in the bright-light condition also tended to report greater reductions of negative daytime symptoms, including significantly fewer days of feeling depressed at the 4-week follow-up, as compared with the control group.
  
  
  CONCLUSIONS
  Two evenings of bright-light exposure phase delayed the circadian rhythms of early-morning awakening insomniacs. It also improved diary and actigraphy sleep measures and improved some indexes of daytime functioning for up to 1 month after light exposure. The study suggests that a brief course of evening bright-light therapy can be an effective treatment for early-morning awakening insomniacs who have relatively phase advanced circadian rhythms.
authors.affiliation: School of Psychology, Flinders University, GPO Box 2100, Adelaide, South Australia 5001. leon.lack@flinders.edu.au
authors.forename: Leon
authors.initials: L
authors.lastname: Lack
authors.forename: Helen
authors.initials: H
authors.lastname: Wright
authors.forename: Kristyn
authors.initials: K
authors.lastname: Kemp
authors.forename: Samantha
authors.initials: S
authors.lastname: Gibbon
mesh_terms: D000328:Adult; D000368:Aged; D001831:Body Temperature / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008550:Melatonin / Q000652:urine; D008875:Middle Aged; D010789:Phototherapy / Q000379:methods*; D012007:Rectum; D020178:Sleep Disorders, Circadian Rhythm / Q000378:metabolism / Q000628:therapy*; D011795:Surveys and Questionnaires
chemical_list: D008550:Melatonin