This site uses cookies to measure how you use the website so it can be updated and improved based on your needs and also uses cookies to help remember the notifications you’ve seen, like this one, so that we don’t show them to you again. If you could also tell us a little bit about yourself, this information will help us understand how we can support you better and make this site even easier for you to use and navigate.

Impact of ambient bright light on agitation in dementia


Barrick, Ann Louise, Sloane, Philip D., Williams, Christianna S., Mitchell, C. Madeline, Connell, Bettye Rose, Wood, Wendy, Hickman, Susan E., Preisser, John S., Zimmerman, Sheryl


International Journal of Geriatric Psychiatry, Volume: 25, No.: 10, Pages.: 1013-1021

Year of Publication



Objective: To evaluate the effect of ambient bright light therapy (BLT) on agitation among institutionalized persons with dementia. Methods: High intensity, low glare ambient lighting was installed in activity and dining areas of a state psychiatric hospital unit in North Carolina and a dementia-specific residential care facility in Oregon. The study employed a cluster-unit crossover design involving four ambient lighting conditions: AM bright light, PM bright light, All Day bright light, and Standard light. Sixty-six older persons with dementia participated. Outcome measures included direct observation by research personnel and completion by staff caregivers of the 14-item, short form of the Cohen-Mansfield Agitation Inventory (CMAI). Results: Analyses of observational data revealed that for participants with mild/moderate dementia, agitation was higher under AM light (p = 0.003), PM light (p < 0.001), and All Day light (p = 0.001) than Standard light. There was also a trend toward severely demented participants being more agitated during AM light than Standard light (p = 0.053). Analysis of CMAI data identified differing responses by site: the North Carolina site significantly increased agitation under AM light (p = 0.002) and PM light (p = 0.013) compared with All Day light while in Oregon, agitation was higher for All Day light compared to AM light (p = 0.030). In no comparison was agitation significantly lower under any therapeutic condition, in comparison to Standard lighting. Conclusions: Ambient bright light is not effective in reducing agitation in dementia and may exacerbate this behavioral symptom. (PsycINFO Database Record (c) 2012 APA, all rights reserved). (journal abstract)

Bibtex Citation

@article{Barrick_2010, doi = {10.1002/gps.2453}, url = {}, year = 2010, month = {jan}, publisher = {Wiley-Blackwell}, volume = {25}, number = {10}, pages = {1013--1021}, author = {Ann Louise Barrick and Philip D. Sloane and Christianna S. Williams and C. Madeline Mitchell and Bettye Rose Connell and Wendy Wood and Susan E. Hickman and John S. Preisser and Sheryl Zimmerman}, title = {Impact of ambient bright light on agitation in dementia}, journal = {Int. J. Geriat. Psychiatry} }


agitation, ambient, ambient bright light therapy, bright, crossover, dementia, design, institutionalized persons, light, phototherapy, therapy

Countries of Study


Types of Dementia

Dementia (general / unspecified)

Types of Study


Type of Outcomes



Hospital Inpatient Care

Type of Interventions

Non-pharmacological Treatment

Non-Pharmaceutical Interventions