There is insufficient evidence to determine whether light therapy is effective in the management of cognitive, sleep, functional, behavioural or psychiatric disturbances in dementia

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. The light sources in the included studies were: a light box placed approximately one metre away from the participants at a height within their visual fields; a light visor worn on their heads; ceiling mounted light fixtures; or dawn-dusk simulation that mimics outdoor twilight transitions. Eight studies met the inclusion criteria. However, three trials were not included in the analyses because of inappropriately reported analyses or inability to retrieve the required data from the original investigators. The studies included in the analyses revealed no adequate evidence of the effectiveness of light therapy in managing cognitive, sleep, functional, behavioural, or psychiatric disturbances associated with dementia.