Effect of bright light and melatonin on cognitive and noncognitive function in elderly residents of group care facilities: a randomized controlled trial.
BACKGROUND
Cognitive decline, mood, behavioral and sleep disturbances, and limitations of activities of daily living commonly burden elderly patients with dementia and their caregivers. Circadian rhythm disturbances have been associated with these symptoms.


OBJECTIVE
To determine whether the progression of cognitive and noncognitive symptoms may be ameliorated by individual or combined long-term application of the 2 major synchronizers of the circadian timing system: bright light and melatonin.


METHODS
A long-term, double-blind, placebo-controlled, 2 x 2 factorial randomized trial performed from 1999 to 2004 with 189 residents of 12 group care facilities in the Netherlands; mean (SD) age, 85.8 (5.5) years; 90% were female and 87% had dementia.


METHODS
Random assignment by facility to long-term daily treatment with whole-day bright (+/- 1000 lux) or dim (+/- 300 lux) light and by participant to evening melatonin (2.5 mg) or placebo for a mean (SD) of 15 (12) months (maximum period of 3.5 years).


METHODS
Standardized scales for cognitive and noncognitive symptoms, limitations of activities of daily living, and adverse effects assessed every 6 months.


RESULTS
Light attenuated cognitive deterioration by a mean of 0.9 points (95% confidence interval [CI], 0.04-1.71) on the Mini-Mental State Examination or a relative 5%. Light also ameliorated depressive symptoms by 1.5 points (95% CI, 0.24-2.70) on the Cornell Scale for Depression in Dementia or a relative 19%, and attenuated the increase in functional limitations over time by 1.8 points per year (95% CI, 0.61-2.92) on the nurse-informant activities of daily living scale or a relative 53% difference. Melatonin shortened sleep onset latency by 8.2 minutes (95% CI, 1.08-15.38) or 19% and increased sleep duration by 27 minutes (95% CI, 9-46) or 6%. However, melatonin adversely affected scores on the Philadelphia Geriatric Centre Affect Rating Scale, both for positive affect (-0.5 points; 95% CI, -0.10 to -1.00) and negative affect (0.8 points; 95% CI, 0.20-1.44). Melatonin also increased withdrawn behavior by 1.02 points (95% CI, 0.18-1.86) on the Multi Observational Scale for Elderly Subjects scale, although this effect was not seen if given in combination with light. Combined treatment also attenuated aggressive behavior by 3.9 points (95% CI, 0.88-6.92) on the Cohen-Mansfield Agitation Index or 9%, increased sleep efficiency by 3.5% (95% CI, 0.8%-6.1%), and improved nocturnal restlessness by 1.00 minute per hour each year (95% CI, 0.26-1.78) or 9% (treatment x time effect).


CONCLUSIONS
Light has a modest benefit in improving some cognitive and noncognitive symptoms of dementia. To counteract the adverse effect of melatonin on mood, it is recommended only in combination with light.


BACKGROUND
controlled-trials.com/isrctn Identifier: ISRCTN93133646.
Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands.
Rixt F
RF
Riemersma-van der Lek
Dick F
DF
Swaab
Jos
J
Twisk
Elly M
EM
Hol
Witte J G
WJ
Hoogendijk
Eus J W
EJ
Van Someren
D000203:Activities of Daily Living; D000339:Affect / Q000187:drug effects; D000369:Aged, 80 and over; D002940:Circadian Rhythm; D003071:Cognition / Q000187:drug effects; D003131:Combined Modality Therapy; D003704:Dementia / Q000517:prevention & control*; D003863:Depression / Q000517:prevention & control*; D004311:Double-Blind Method; D005260:Female; D006707:Homes for the Aged; D006801:Humans; D008027:Light; D008029:Lighting; D008297:Male; D008550:Melatonin / Q000009:adverse effects / Q000627:therapeutic use*; D009735:Nursing Homes; D010789:Phototherapy; D012890:Sleep / Q000187:drug effects; D012893:Sleep Wake Disorders / Q000517:prevention & control
D008550:Melatonin