For people with mild traumatic brain injury (TBI), daily morning exposure to blue-light therapy may reduce depression and other post-concussion symptoms, according to a small study.

US researchers enrolled 35 young adults (mean age 26), diagnosed with mild TBI during the past 18 months, in a randomised, double-blind study.

Each morning for six weeks, 17 participants (five male) used a tabletop device that shined bright blue light for 30 minutes, while the remaining 18 (eight male) received amber-light therapy as a control.

At baseline and after six weeks of treatment, both groups completed standard assessments of depression and other concussion symptoms, such as headache, fatigue and problems with sleep, memory and concentration.