Bright Light Therapy for Non-motor Symptoms in Parkinson's Disease

Exclusion Criteria

• •1. Atypical or secondary forms of parkinsonism
• •2. Co-existent significant sleep apnea (as assessed by polysomnography- derived apnea/hypopnea index ≥15 events/hr of sleep)
• •3. Co-existent restless legs syndrome (RLS), as assessed by the International Classification of Sleep Disorders (ICDS) diagnostic criteria for RLS
• •4. Cognitive impairment as determined by the Mini-Mental State Examination (MMSE) score of ≤ 26
• •5. Presence of depression defined as the Beck Depression Inventory (BDI) score \>14
• •6. Untreated hallucinations or psychosis (drug-induced or spontaneous)
• •7. Use of hypno-sedative drugs for sleep or stimulants; participants will be allowed to taper these drugs and will become eligible 4 weeks after the taper is completed
• •8. Use of Selective Serotonin Reuptake Inhibitors (SSRIs) / Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs) antidepressants, unless the participant has been on a stable dose for at least 3 months prior to the screening
• •9. Use of medications known to affect melatonin secretion, such as lithium, alpha- and beta-adrenergic antagonists
• •10. Shift work, currently or within the prior 3 months
• •11. Travel through ≥ 2 time zones within 60 days prior to study screening
• •12. Hematocrit \<32 mm3
• •13. Pre-existing glaucoma/retinal disease contraindicated for light therapy (LT)
• •14. Dense cataracts
• •15. Use of medications known to photosensitize retinal tissue (phenothiazines, chloroquine, amiodarone, St. John's Wort)
• •16. Unstable/serious medical illness.
• •17. Pregnancy