Objective This review aimed to determine the efficacy of blue-wavelength light therapy (BWLT) for post-traumatic brain injury (TBI) sleepiness, sleep disturbance, depression, and fatigue. Methods Pubmed, Scopus, Web of Science, Cochrane Library, Academic Search Complete, and CINAHL. Included trials were randomized controlled trials (RCTs) of BWLT in adults with a history of TBI. Outcomes of interest included sleepiness, sleep disturbance, depression, or fatigue. Two reviewers independently screened the searched items, selected the trials, extracted the data, and rating the quality of trials. We aggregated the data using a random-effect, frequentist network meta-analysis (NMA). Results We searched the databases on July 4, 2020. This review included four RCTs of 117 patients with a history of TBI who were randomized to received BWLT, amber light therapy (ALT), or no light therapy (NLT). Moderate-quality evidence revealed that: i) BWLT was significantly superior to NLT in reducing depression (SMD = 0.81, 95% CI = 0.20 to 1.43) ii) BWLT reduced fatigue at a significantly greater extent than NLT (SMD = 1.09, 95% CI = 0.41 to 1.76) and ALT (SMD = 1.00, 95% CI = 0.14 to 1.86). Low-quality evidence suggested that BWLT reduced depression at a greater extent than ALT (SMD = 0.57, 95% CI = 0.04 to 1.10). Low-quality evidence found that the dropout rates of those receiving BWLT and ALT were not significantly different (RR = 3.72, 95% CI = 0.65 to 21.34). Conclusion Moderate-quality evidence suggests that BWLT may be useful for post-TBI depression and fatigue.

Background: We aimed to determine the efficacy of blue-wavelength light therapy (BWLT) for post-traumatic brain injury (TBI) sleepiness, sleep disturbance, depression, and fatigue.Methods: We searched six databases for randomized controlled trials of BWLT for adults with a history of TBI. Outcomes of interest included sleepiness, sleep disturbance, depression, or fatigue. We conducted random-effect frequentist network meta-analyses (NMA) to compare the efficacy and a pairwise meta-analysis to examine the dropout rates.Results: We included four randomized controlled trials that compared BWLT, amber light therapy, and no light therapy. BWLT was significantly superior in reducing depression as compared to amber light therapy (SMD = 0.57, 95% CI = 0.04 to 1.10) and no light therapy (SMD = 0.81, 95% CI = 0.20 to 1.43). BWLT was also significantly superior in reducing fatigue as compared to amber light therapy (SMD = 1.00, 95% CI = 0.14 to 1.86) and no light therapy (SMD = 1.09, 95% CI = 0.41 to 1.76). There was no significant heterogeneity of depression and fatigue data (I2 = 0% for both). The relative risk of dropout rates (95% CI) shows no significant difference between BWLT and amber light therapy groups (RR = 3.72, 95% CI = 0.66 to 21.34, I2 = 0%).Conclusion: BWLT may be effective for post-TBI depression and fatigue. Due to the risks of bias and the inability to exclude publication bias among included studies, the current evidence remains insufficient to support the clinical application of BWLT for post-TBI depression and fatigue. Protocol registration: The protocol of this systematic review is available at Open Science Framework (https://osf.io/yf2qe/).

Objective Behavioral symptoms are common after traumatic brain injury (TBI), but their treatments remain unsatisfactory. This systematic review and meta-analysis compared the efficacy and acceptability between blue-wavelength light therapy (BWLT) and long-wavelength/no light therapy (LW/NLT) for post-TBI sleepiness, sleep disturbance, depressive symptoms, and fatigue. Methods This study included randomized controlled trials comparing the effects of BWLT and LW/NLT on post-TBI sleepiness, sleep disturbance, depression, or fatigue. We searched Pubmed, Embase, CINAHL, and Cochrane Central Register of Controlled of Trials on April 13, 2022. The revised tool for assessing the risk of bias in randomized trials was applied. We performed a frequentist pairwise meta-analysis using a random-effects model. Results Of 233 retrieved records, six trials (N = 278) were included in this meta-analysis. TBIs ranged from mild to severe, and the interventions were administered for a median of 35 days. Most trials delivered light therapy via lightboxes. Three trials had a high risk of bias. BWLT was significantly superior to LW/NLT in reducing sleep disturbance (5 trials; SMD = -0.63; 95% CI = -1.21 to -0.05; p = 0.03; I2 = 61%) and depressive symptoms (4 trials; SMD = -1.00; 95% CI = -1.62 to -0.38; p < 0.01; I2 = 56%). There were trends that BWLT was superior to LW/NLT in reducing sleepiness (6 trials; SMD = -0.92; 95% CI = -1.84 to 0.00; p = 0.05; I2 = 88%) and fatigue (4 trials; SMD = -1.44; 95% CI = -2.95 to 0.08; p = 0.06; I2 = 91%). All-cause dropout rates were not significantly different between groups. Conclusion Limited and heterogenous evidence suggests that short-term BWLT is well accepted, has a large treatment effect on post-TBI depressive symptoms, and may have a moderate treatment effect on post-TBI sleep disturbance.