Effect of Bright Light on Mood and Sleep in Parkinson's Disease (LightPD)

International Parkinson Foundation ('IPF'), Hoofddorp, The Netherlands, Parkinsonvereniging, Bunnik, the Netherlands, Netherlands Brain Foundation, Netherlands Institute for Neurosciences, Amsterdam, The Netherlands, GGZ inGeest

The purpose of this clinical trial is to investigate whether light therapy is a suitable treatment option for depression and insomnia in Parkinson's disease.

The quality of life of patients with Parkinson's disease and their caretakers is mainly influenced by so called non-motor symptoms. This includes neuropsychiatric consequences of the disease like depression and sleeping problems. The incidence of depressed mood in patients with Parkinson is approximately 50%, the incidence for sleeping problems is 90%. These symptoms are often overlooked and even if recognized, inadequately treated. The treatment of mood and sleep disturbances in Parkinson patients is hampered by adverse effects, incomplete responses to the usual treatments and the absence of specific treatment options for these symptoms in Parkinson's disease. On the basis of the hypothesis of disturbed functioning of the suprachiasmatic nucleus in Parkinson's disease it is expected that stimulation of this nucleus by bright light therapy will result in improved functioning on multiple different domains: mood, sleep, motor functions, quality of life and circadian rhythms. Because there are virtually no side effects and the possibility of home treatment, light therapy is expected to be highly appreciated by the patients.

Light from a commercially available table-mounted lightbox (Brazil, Lumie, Cambridge UK) [dimensions 50.2 x 32 x 15.4 cm] equipped with 3x36W Fluorescent bulbs (Osram 954), reflectors and a diffuser screen providing 10,000 lux at 30 cm eye level distance. therapy consists of 30 minutes light exposure in the morning and evening during 3 months.

200 lux light from a commercially available table-mounted lightbox (Brazil, Lumie, Cambridge UK) [dimensions 50.2 x 32 x 15.4 cm] To lower the intensity to 200 lux the bulbs are enwrapped with one layer of L299s neutral density filter (LEE Filters, Andover, UK). Therapy consists of 30 minutes light exposure in the morning and evening during 3 months.

using Hamilton Depression Rating Scale (HDRS - 17 items) and Geriatric Depression Scale-30 (GDS - 30 items) at baseline (T0), halfway therapy, six weeks (T1), end of therapy, three months (T2), at 1 month follow-up (T3), 3 months follow-up (T4) and 6 months follow-up (T5). The direct treatment effect (= difference score between baseline and end of treatment), The long-lasting treatment effect (= difference score between baseline and end of follow-up). The dichotomous treatment response (> 50 % decrease score at T2), in order to calculate the Numbers Needed to Treat (NNT).

T0: baseline, T1: change from T0, T2: change from T0, T3: follow-up, change from T0, T4: follow-up, change from T0, T5: follow-up, change from T0

using Scales for Outcomes in Parkinson's Disease-Sleep subscale (SCOPA-sleep - 14 items) assessed at baseline (T0), after 6 weeks of light therapy (T1), after 3 months of light therapy (end of treatment, T2), 1 month post-treatment (T3), 3 months post-treatment (T4) and 6 months post-treatment (T5).

T0: baseline, T1: change from T0, T2: change from T0, T3: follow-up, change from T0, T4: follow-up, change from T0, T5: follow-up, change from T0

using Unified Parkinson's Disease Rating Scale-Section III motor score (UPDRS-III - 14 items) at 3 time points: at baseline (T0), after 3 months of light therapy (T2) and 6 months follow-up (T5).

T0: baseline, T2: after three months therapy, change from T0, T5: six month follow-up, change from T0

using the World Health Organization Quality of Life Assessment Short Version (WHOQOL-BREF) assessed at 3 time points, at baseline (T0), after 3 months of light therapy (T2) and 6 months follow-up (T5).

T0: baseline, T2: after three months therapy, change from T0, T5: six month follow-up, change from T0

Circadian rhythm as measured by melatonin and cortisol day/night curves and actigraphy are assessed at 6 time points, at baseline (T0), after 6 weeks of light therapy (T1), after 3 months of light therapy (T2), 1 month follow-up (T3), 3 months follow-up (T4) and 6 months follow-up (T5).

T0: baseline, T1: change from T0, T2: change from T0, T3: follow-up, change from T0, T4: follow-up, change from T0, T5: follow-up, change from T0

using the Zarit Burden Interview (ZBI - 22 items) for caregivers, assessed at 3 time points, at baseline (T0), after 3 months of light therapy (T2) and 6 months follow-up (T5).

T0: baseline, T2: after three months therapy, change from T0, T5: six month follow-up, change from T0

Inclusion Criteria: Parkinson's disease depression Exclusion Criteria: psychosis mania suicidality retinopathy previous light treatment use of photosensitising medication

Rutten S, Vriend C, Smit JH, Berendse HW, van Someren EJW, Hoogendoorn AW, Twisk JWR, van der Werf YD, van den Heuvel OA. Bright light therapy for depression in Parkinson disease: A randomized controlled trial. Neurology. 2019 Mar 12;92(11):e1145-e1156. doi: 10.1212/WNL.0000000000007090. Epub 2019 Feb 15.

Rutten S, Vriend C, Smit JH, Berendse HW, Hoogendoorn AW, van den Heuvel OA, van der Werf YD. A double-blind randomized controlled trial to assess the effect of bright light therapy on depression in patients with Parkinson's disease. BMC Psychiatry. 2016 Oct 21;16(1):355. doi: 10.1186/s12888-016-1050-z.