Bright Light Therapy for Parkinson Disease: A Literature Review and Meta-Analysis of Randomized Controlled Trials

Sleep disorders and depression are significant nonmotor symptoms (NMSs) of Parkinson disease (PD). However, few effective, evidence-proven medical treatments are available for alleviating these symptoms. Bright light therapy (BLT) is a well-established treatment for circadian rhythm sleep disorders and seasonal affective disorder. The present study conducted a literature review for the effect of BLT on PD, especially a meta-analysis of randomized controlled trials (RCTs). We searched for studies using the PubMed and Cochrane Library databases. The major outcomes were the effects on sleep and depression. The effect on motor symptoms was also analyzed as a secondary outcome. This study was registered with PROSPERO (CRD42020204454). Six studies were included in the literature review only, and the other five RCTs were included in the meta-analysis. Despite the positive effects of BLT on PD patients, which were demonstrated in noncontrolled studies, in the meta-analysis of the RCTs, BLT did not significantly improve the depressive symptoms (standardized mean difference (SMD): −0.15, 95% confidence interval (CI): −0.48 to 0.17, p = 0.36) and excessive daytime sleepiness (EDS) (SMD: −0.12, 95% CI: −0.49 to 0.25, p = 0.53) in PD patients. Regarding motor symptoms, no significant beneficial effects were conferred (SMD: −0.11, 95% CI: −0.44 to 0.21, p = 0.49). In conclusion, BLT did not significantly alleviate depression and sleepiness. The inconsistency between BLT protocols, such as the varied timing, dosages, and treatment durations, may render BLT’s efficacy difficult to demonstrate. The small effect size obtained from the present meta-analysis indicates that future RCTs are necessary, for which BLT protocols are standardized and more patients are enrolled to determine whether a significant therapeutic benefit was conferred.

Effects of Dynamic Bedroom Lighting On Measures of Sleep and Circadian Rest-Activity Rhythm in Inpatients With Major Depressive Disorder

Bright light therapy is an effective treatment option for seasonal and non-seasonal affective disorders. However up to now, no study has investigated effects of dynamic bedroom lighting in hospitalized patients with major depression. A bedroom lighting system, which automatically delivered artificial dawn and dusk and blue-depleted nighttime lighting (DD-N lighting) was installed in a psychiatric ward. Patients with moderate to severe depression were randomly assigned to stay in bedrooms with the new lighting or standard lighting system. Patients wore wrist actimeters during the first two treatment weeks. Additionally, hospitalization duration and daily psychotropic medication were retrieved from patients’ medical charts. Data from thirty patients were analyzed. Patients under DD-N lighting generally woke up earlier (+20 minutes), slept longer (week 1: +11 min; week 2: +27 min) and showed higher sleep efficiency (+2.4%) and shorter periods of nighttime awakenings (-15 minutes). In the second treatment week, patients started sleep and the most active 10-hour period earlier (-33 min and -64 min, respectively). This pilot study gives first evidence that depressed patients’ sleep and circadian rest/activity system may benefit from adjunctive bedroom lighting when starting inpatient treatment.

Light Enhanced Cognitive Behavioral Therapy (CBT-I+Light) for Insomnia and Fatigue During Chemotherapy for Breast Cancer: A Randomized Controlled Trial

Study Objectives Sleep problems are common during chemotherapy for breast cancer (BC). We evaluated whether combined brief cognitive behavioral and bright light therapy (CBT-I+Light) is superior to treatment as usual with relaxation audio (TAU+) for insomnia symptoms and sleep efficiency (primary outcomes). Methods We randomized women receiving intravenous chemotherapy, stratified by tumor stage and insomnia severity index (ISI), to 6-weeks CBT-I+Light or TAU+. CBT-I+Light included one in-person session, one telephone call, seven emails, and 20 minutes bright light each morning. TAU+ comprised usual treatment and two emails with relaxation audio tracks. Patient-reported outcomes were assessed at baseline, midpoint (week 3), post (week 6) and 3-month follow-up. Results Women (N = 101) were randomly assigned to CBT-I+Light or TAU+. The CBT-I+Light group showed significantly greater improvement in insomnia symptoms than the TAU+ group (-5.06 vs -1.93, P = .009; between-group effect size [ES] = .69). At 3-month follow-up, both groups were lower than baseline but did not differ from each other (between-group ES = .18, P = .56). CBT-I+Light had higher patient-reported sleep efficiency than TAU+ immediately after the start of intervention (P = .05) and significantly greater improvement in fatigue (between-group ES = .59, P = .013) and daytime sleep-related impairment (between-group ES = .61, P = .009) than the TAU+ group. Conclusion CBT-I+Light had a clinically significant impact on insomnia and fatigue with moderate effect sizes. Results support offering cognitive behavioral therapy for insomnia and bright light therapy during chemotherapy for breast cancer to help manage sleep and fatigue.

Circadian Rhythm Dysregulation and Restoration: The Role of Melatonin

Sleep is an essential component of overall human health but is so tightly regulated that when disrupted can cause or worsen certain ailments. An important part of this process is the presence of the well-known hormone, melatonin. This compound assists in the governing of sleep and circadian rhythms. Previous studies have postulated that dysregulation of melatonin rhythms is the driving force behind sleep and circadian disorders. A computer-aided search spanning the years of 2015–2020 using the search terms melatonin, circadian rhythm, disorder yielded 52 full text articles that were analyzed. We explored the mechanisms behind melatonin dysregulation and how it affects various disorders. Additionally, we examined associated therapeutic treatments including bright light therapy (BLT) and exogenous forms of melatonin. We found that over the past 5 years, melatonin has not been widely investigated in clinical studies thus there remains large gaps in its potential utilization as a therapy.

Total Sleep Deprivation Followed by Bright Light Therapy as Rapid Relief for Depression: A Pragmatic Randomized Controlled Trial

Background: Total sleep deprivation (TSD) combined with bright light therapy (BLT) has been suggested as a valuable add-on to standard treatment for rapid relief of depression. However, there is a lack of randomized controlled trials in real-life clinical settings. The aim of this pragmatic randomized clinical trial was to investigate the effectiveness, acceptance, and feasibility of TSD combined with BLT as add-on to standard treatment for depression in a real-life clinical setting.Methods: Thirty-three inpatients were randomly assigned to either: a) an intervention group receiving a single-night TSD followed by 6 days BLT (10.000 lux, 30 min/day) as add-on to standard treatment; or b) a control group receiving a short sleep-hygiene consultation in addition to standard treatment. The follow-up period was 1 week.Results: No statistical differences were found in response rates, reduction of depressive and insomnia symptoms, length of stay, readmission rate, and clinical improvement. Both groups reported positive experiences toward the received treatment with low drop-out rates.Conclusions: One-night TSD followed by BLT was not effective as a rapid relief for depression at 1-week follow-up; however, the treatment was feasible and well-tolerated.

Bright Light Therapy in Older Adults with Moderate to Very Severe Dementia: Immediate Effects on Behavior, Mood and Physiological Parameters

Bright light therapy (BLT) has demonstrated positive short- and long-term effects in people with cognitive impairment or dementia; however, the immediate impact of BLT sessions has been scarcely investigated. In this study, we aimed to explore the immediate effects of BLT on behavior, mood, and physiological parameters (oxygen saturation/heart rate) in a sample of institutionalized older adults with moderate to very severe dementia, with a median age of 85.0 (interquartile range, IQR, 82.0–90.0), being higher in men (87.0 years, IQR 80.0–94.0) than in women (84.5 years, IQR 82.0–89.5). The BLT protocol consisted of 30-minute morning sessions of 10,000 lux, Monday through Friday, for 4 weeks. The physiological parameters were recorded immediately before and after each session by pulse oximetry. Mood and behavior were assessed before, after, and during the sessions using the Interact scale. Post-session Interact scores showed a significant decrease in the items Tearful/sad and Talked spontaneously, and a significant increase in the items Enjoying self, active or alert, and Relaxed, content or sleeping appropriately. Interact scores during the sessions reflected a significant decrease in the speech-related items. Both physiological parameters changed positively from before to after sessions. Our results suggest that BLT provides immediate positive effects on mood, stimulation level, and physiological parameters, as well as a trend toward decreased speech. More robust research is needed to further explore the immediate impact of BLT. This study is registered with Clinicaltrials.gov (NCT04949984).