Forbes D, Culum I, Lischka AR, Morgan DG, Peacock S, Forbes J, Forbes S. Light therapy for managing cognitive, sleep, functional, behavioural, or psychiatric disturbances in dementia.
Cochrane Database Syst Rev 2009:CD003946. [PMID:
19821317 DOI:
10.1002/14651858.cd003946.pub3]
[Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND
Rest-activity and sleep-wake cycles are controlled by the endogenous circadian rhythm generated by the suprachiasmatic nuclei (SCN) of the hypothalamus. Degenerative changes in the SCN appear to be a biological basis for circadian disturbances in people with dementia, and might be reversed by stimulation of the SCN by light.
OBJECTIVES
The review assesses the evidence of effectiveness of light therapy in managing cognitive, sleep, functional, behavioural, or psychiatric disturbances associated with dementia.
SEARCH STRATEGY
The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (CDCIG), The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL and LILACS were searched on 4 March 2008 using the terms: "bright light*", "light box*", "light visor*", "dawn-dusk*", phototherapy, "photo therapy", "light therapy" "light treatment", light* . The CDCIG Specialized Register contains records from all major health care databases (The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS) as well as from many trials databases and grey literature sources.
SELECTION CRITERIA
All relevant, randomized clinical trials in which light therapy, at any intensity and duration, was compared with a control group for the effect on managing cognition, sleep, function, behavioural, or psychiatric disturbances (as well as changes in institutionalization rates or cost of care) in people with dementia of any type and degree of severity.
DATA COLLECTION AND ANALYSIS
Three reviewers independently assessed the retrieved articles for relevance and methodological quality, and extracted data from the selected studies. Statistically significant differences in outcomes between the treatment and control groups at end of treatment and follow-up were examined. Each study was summarized using a measure of effect (e.g. mean difference).
MAIN RESULTS
Eight trials met the inclusion criteria. However, three of the studies could not be included in the analyses because of inappropriate reported study analyses or inability to retrieve the required data from the investigators. This review revealed no adequate evidence of the effectiveness of light therapy in managing cognition, sleep, function, behaviour, or psychiatric disturbances associated with dementia.
AUTHORS' CONCLUSIONS
There is insufficient evidence to assess the value of light therapy for people with dementia. Most of the available studies are not of high methodological quality and further research is required.
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