Bright light therapy or phototherapy is frequently cited as an effective treatment for major depressive disorder with seasonal pattern, more commonly known as seasonal affective disorder (SAD). This is perhaps the most common application of bright light therapy in the field of mental health, although it has also been used to reset circadian rhythms and in the management of disorders such as delayed sleep phase syndrome. If you are aware of bright light therapy or have used it with clients, it is likely because of its connection to these disorders.
More recently though, researchers have been exploring novel uses of bright light therapy and its potential role in the treatment of other mental health conditions. This research may be of particular interest to those who work with military-connected populations as the conditions being studied are particularly common in military populations: post-traumatic stress disorder (PTSD), traumatic brain injury (TBI), and chronic pain. In this blog post, we will briefly summarize the findings of several of these studies and discuss potential implications for providers working with military-connected clients.
Youngstedt and colleagues (2021) recently published the findings from a randomized controlled trial examining the impact of morning bright light treatment on PTSD symptoms in veterans with combat-related PTSD. Those in the bright light condition showed significantly greater improvements as measured by the Clinician Assessed PTSD Scale (CAPS) and the Clinical Global Impressions Scale (CGI). They also observed a greater rate of response to treatment on both the CAPS and the PTSD Checklist-Military (PCL-M) in those receiving light treatment.
The findings from a second study (Keil, Eillott, McBride, Calahan, & Lim, 2021) examining the impact of morning bright light therapy, this one on comorbid PTSD and TBI, were presented at the Experimental Biology 2021 Meeting, held online. This study examined the effects of bright light therapy on cognitive function in 16 veterans with mild TBI (mTBI) and PTSD diagnoses. Study participants were already undergoing cognitive rehabilitative therapy (CRT); half were also included in a daily morning bright light therapy condition. While self-reported cognitive function, sleep, depression, and neuropsychiatric trauma symptoms failed to improve in the CRT alone condition, those who received adjunctive light therapy demonstrated significant improvements across all of those categories.
Finally, an open trial conducted by Burgess and colleagues (2019) looked at the impact of light therapy on chronic low back pain in Veterans. This study used a within-subjects design that assessed pain, PTSD symptoms, and sleep quality in 37 participants through baseline and daily light treatment periods. Participants reported reduced pain intensity and sensitivity, fewer pain behaviors, decreased PTSD symptoms, and improved sleep quality following the 13-days of morning bright light therapy.
These three studies present preliminary findings that bright light therapy appears to be beneficial for use in the treatment of a variety of conditions that impact service members and veterans, including PTSD, TBI, and chronic pain. Of particular note was the common finding across the studies that the bright light intervention significantly impacted sleep and circadian rhythms. This commonality led to speculation across the teams about the role of sleep modifications as a potential explanation for the positive impact of light therapy. The research teams also agreed that more research is warranted to better understand the extent of and mechanisms behind the impact of bright light therapy on these conditions. For providers who work with military-connected individuals, these studies provide initial support for the benefits of integrating morning bright light therapy into a variety of treatment protocols for these conditions.
The opinions in CDP Staff Perspective blogs are solely those of the author and do not necessarily reflect the opinion of the Uniformed Services University of the Health Science or the Department of Defense.
Jenny Phillips, Ph.D., is the Assistant Director of Evaluation for the Center for Deployment Psychology (CDP) at the Uniformed Services University of the Health Sciences in Bethesda, MD.
Youngstedt, S. D., Kline, C. E., Reynolds, A. M., Crowley, S. K., Burch, J. B., Khan, N., & Han, S. (2021). Bright light treatment of combat-related PTSD: A randomized controlled trial. Military Medicine. https://doi.org/10.1093/milmed/usab014
Keil, A., Elliott, J., McBride, A., Callahan, M., & Lim, M. Morning bright light therapy for sleep to augment cognitive rehabilitation in Veterans with comorbid traumatic brain injury and post‐traumatic stress disorder: A pilot study. The FASEB Journal, 35, S1. https://doi.org/10.1096/fasebj.2021.35.S1.03216
Burgess, H. J., Rizvydeen, M., Kimura, M., Pollack, M. H., Hobfoll, S. E., Rajan, K. B., & Burns, J. W. (2019). An open trial of morning bright light treatment among US military veterans with chronic low back pain: A pilot study. Pain Medicine, 20(4), 770-778. https://doi.org/10.1093/pm/pny174