The treatment of early-morning awakening insomnia with 2 evenings of bright light

• Published in: Sleep (New York, N.Y.) N.Y.), 2005-05, Vol.28 (5), p.548-549
• Main Authors: TUREK, Fred W, LACK, Leon, WRIGHT, Helen, KEMP, Kristyn, GIBBON, Samantha
• Format: Article
• Language: English
• Subjects: Activity levels. Psychomotricity; Adult; Aged; Biological and medical sciences; Body Temperature - physiology; Female; Follow-Up Studies; Fundamental and applied biological sciences. Psychology; Humans; Male; Melatonin - urine; Middle Aged; Phototherapy - methods; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rectum; Sleep Disorders, Circadian Rhythm - metabolism; Sleep Disorders, Circadian Rhythm - therapy; Surveys and Questionnaires; Vigilance. Attention. Sleep
• ISSN: 0161-8105; 1550-9109
• DOI: 10.1093/sleep/28.5.616

To assess the effectiveness of brief bright-light therapy for the treatment of early-morning awakening insomnia. 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. 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. 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.