The effect of ambient bright light therapy on depressive symptoms in persons with dementia.
OBJECTIVE
To assess the effect of ambient bright light therapy on depressive symptoms in persons with dementia.


METHODS
A cluster-unit crossover intervention trial involving four lighting conditions: morning bright light, evening bright light, all-day bright light, and standard light.


METHODS
The common areas of two geriatric units in a state-operated psychiatric hospital in North Carolina and in a dementia-specific residential care facility in Oregon.


METHODS
Sixty-six older adults with dementia.


METHODS
Ambient bright light therapy was delivered through a high-intensity, low-glare lighting system installed in the public areas of study units at both sites. Each lighting condition was provided for multiple 3-week periods in a predetermined sequence.


METHODS
Staff caregivers completed the Cornell Scale for Depression in Dementia (CSDD) in the last week of each 3-week period to provide information about participants' moods.


RESULTS
Analysis indicated a sex-by-treatment interaction (P=.008). Significant sex differences were found in CSDD scores in response to evening light (P=.003), all-day light (P=.001), and standard light (P</=.001). Depressive symptoms were lowest for women and highest for men during morning light.


CONCLUSIONS
Findings do not support the use of ambient bright light therapy as a treatment for depressive symptoms in persons with dementia, although a subpopulation of persons with dementia may benefit from this intervention. It is likely that individual rather than unit-level interventions are a more effective strategy for delivering bright light therapy for this population.
Hickman
Susan E
SE
School of Nursing, Oregon Health & Science University, Portland, Oregon, USA. hickmans@ohsu.edu
Barrick
Ann Louise
AL
Williams
Christianna S
CS
Zimmerman
Sheryl
S
Connell
Bettye Rose
BR
Preisser
John S
JS
Mitchell
C Madeline
CM
Sloane
Philip D
PD
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D002940:Circadian Rhythm; D018592:Cross-Over Studies; D003863:Depression / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D005260:Female; D015577:Geriatric Assessment; D006778:Hospitals, Psychiatric; D006783:Hospitals, State; D006801:Humans; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D009922:Oregon; D010552:Personality Assessment; D010789:Phototherapy; D012931:Social Environment; D017211:Treatment Failure