The primary aim of this study is to compare the efficacy of timed-BLT (BLT group) in reducing excessive daytime sleepiness in patients with Parkinson's disease, when compared to a timed-inactivated negative ion generator (active-control group).~The secondary aims of the study are to examine the effect of timed-BLT on other non-motor symptoms, including depression, fatigue; and the quality of life.~Additional analyses will be carried out to examine the efficacy of the timed-placebo as compared to the random-time placebo (placebo group).
This is a randomized placebo- and active-controlled trial for assessing the efficacy of bright light therapy for sleep and mood symptoms in patients with Parkinson's disease