The research is part of a larger study that looks at the effects of blue wavelength light therapy as a way to help people recover faster from their concussions, says lead author William D. “Scott” Killgore, PhD, a professor and clinical neuropsychologist at the University of Arizona College of Medicine in Tucson. “On average, about half of people who have a concussion will go on to have some sort of sleep-related issue,” says Dr. Killgore. “We thought if we could get people sleeping better that might help them recover faster,” he adds. The small study included 35 people with an average age of 26 who had been diagnosed with a concussion over the last 18 months. One-half of the participants received blue light therapy for 30 minutes each morning for six weeks while the other half received a placebo of amber light therapy. At the onset and end of the study, both groups took tests to measure symptoms of depression with the Beck Depression Inventory. Other common concussion symptoms, including headache, fatigue, and problems with sleep, memory, and concentration, were also assessed. Investigators found that people who received the blue light therapy had significant improvement on the depression scale — they improved by 22 percent compared with a 4 percent worsening in mood for the placebo group. There was also an association with improvements in sleep disturbance, fatigue, concentration, restlessness, and irritability in the blue light group; no associations with those improvements were found in the placebo group. “We believe blue light shifted circadian rhythms, and it helped people be less sleepy during the daytime,” says Killgore. “We also observed areas in the brain that seemed to enlarge in terms of brain volume, as well as improve connectivity in some of the pathways in the brain, so that those areas could talk to each other better,” he says.
Why Blue Light Therapy Might Be the Answer
There are a few reasons that sleep may aid concussion recovery, according to Killgore. “There’s evidence that during sleep you are actually clearing out many of the neurotoxins that build up in the brain and can cause damage,” he says. Sleep also helps in the development of a type of brain cell that insulates your neurons, says Killgore. “These cells grow more if you’re getting good sleep, which is another reason why we believe if we improve sleep it might help the brain to repair itself faster.” A mild TBI, also called a concussion, is the result of a bump, blow, or jolt to the head that interrupts normal brain function. A mild TBI is defined as when the changes to mental state or consciousness are short, lasting about 30 minutes or less. Post-concussion syndrome (PCS) can occur in both mild and severe TBIs. A diagnosis of PCS can be made when symptoms last for more than two weeks after the initial injury, according to the Concussion Legacy Foundation. Symptoms of post-concussion syndrome can include:
HeadachesDizzinessFatigueIrritabilityDifficulty concentrating and performing mental tasksImpairment of memoryInsomniaReduced tolerance to stress, excitement, or alcohol
There is a lot of media attention about concussions, but the people who are still experiencing symptoms for weeks or months later after the event can be part of a “forgotten” population, says Jay Alberts, PhD, researcher and director of the Concussion Center at Cleveland Clinic in Ohio. Dr. Alberts was not involved in this research. “I think this therapy could potentially help a significant number of people in the post-concussive world,” says Alberts. “Sleep is a very important variable in terms of facilitating recovery,” he adds. This research should give people with post-concussion syndrome some level of hope, says Alberts. “If we can start to address these very important sleep issues, that would be fantastic.” Could all these improvements be chalked up to better sleep, or is there something special about blue light therapy? There are probably multiple pathways that are leading to some of these improvements in symptoms, according to Killgore. “The primary thing this study looked at was improvement in sleep, but it’s also been shown that light therapy can be very effective for mood in general,” he adds, noting that using blue light therapy in the morning has also been shown to help people with seasonal affective disorder, such as in a study published in 2016 in BMC Psychiatry. “Blue light also seems to have benefits in making the brain more alert and making people less sleepy during the day, which tends to improve overall mood,” he says.
Future Research With Blue Light Therapy
“The reason we focus on blue light is because there is a special kind of receptor in the back of the eye that responds only to blue colored light,” explains Killgore. Stimulation with this light goes directly to the brain’s clock and it resets the clock a little bit, he says. “It can help a person get on track with their sleep-wake patterns. If you’re using it in the mornings it helps you to get a little bit more sleep in the evening and you’ll fall asleep better,” says Killgore. The next step in research is to identify the brain mechanisms that are involved with blue light therapy, says Killgore. “One of my coauthors is currently working on a study where he is stimulating people with light while they’re inside the brain machine scanner to look at specific areas that seem to be playing a role in this response,” he says. “We have a hypothesis that it’s a particular area that activates a neurotransmitter that also plays a role in depression,” he adds. Killgore and his team also want to dig deeper to find out why blue light therapy seems to be effective in some people but not in others. “We want to understand why everyone doesn’t respond in the same way,” he adds. Blue light devices are available already; you don’t have to have a prescription to use it, says Killgore. “You can buy them online; if it’s blue wavelength light and you use it in the morning, it might be helpful,” he says. Many of the same positive effects could probably be achieved by just sitting outside drinking your morning beverage as the sun comes up, adds Killgore. “I would caution people not to start self-treating with blue-light therapy,” says Alberts. “I wouldn’t want someone to think, ‘I don’t need to see my provider or physician because I’ve got this blue light and I can take care of it myself.’” If you are interested in trying blue-light therapy, talk to your doctor about it first, he recommends.
