In a small pilot study, researchers have obtained encouraging results in using bright-light therapy to treat people with symptoms of post-traumatic stress disorder (PTSD).
In addition to trauma-related symptoms such as flashbacks, people with PTSD often report depressed mood and reduced quantity and quality of sleep. The partial overlap in symptoms with those of depression led Alyson K. Zalta, Ph.D., a 2016 BBRF Young Investigator now at the University of California, Irvine, and colleagues, to test whether bright-light exposure early in the day might help in PTSD, as it sometimes can in depression and seasonal mood disorder.
Past tests of bright-light therapy indicate that its effectiveness has much to do with the time of day in which it is delivered and the frequency and duration of treatments. There is evidence that people with the most intense PTSD symptoms have what scientists call “an evening chronotype.” This means the body’s natural 24-hour circadian rhythm is shifted later in the day, resulting in sleep disturbances.
Dr. Zalta and colleagues used a commercially available, wearable bight-light device to see whether one hour of bright-light exposure in the morning might shift patients’ circadian cycle back “toward morningness.”
The device used in the trial, called Re-timer, looks like a pair of oversized goggles with built-in LED lighting elements surrounding the eyes. The team also devised a “placebo” version of the same device. In a group of 15 volunteers who self-reported PTSD symptoms, nine received the “active” device and six the placebo version.
The results after 4 weeks of self-administered early-morning treatments led the team to conclude that bright-light treatment “was acceptable and feasible for patients,” and despite the small size of the study, appeared to help those in in the “active” group, with improvements over baseline symptoms.
Compliance wasn’t ideal. Participants initiated light therapy on 77% of treatment days, and averaged only 35 minutes per day on the device within the appointed time slot. Thus, many failed to receive what the researchers considered a minimally active daily course of treatment.
Those in the “active” group did, however, experience a circadian shift with the amount of light they received, as evidenced by earlier morning wake times. And “a higher proportion of those in the active group demonstrated a clinically meaningful improvement in PTSD symptoms,” the team reported April 17th in the journal Depression & Anxiety.
The team hopes to test the concept on a larger scale, and will explore ways of bringing patient compliance within the range they regard most likely to produce therapeutic results. The team also included 2003 BBRF Independent Investigator Mark Pollack, M.D.
Dr. Zalta commented: “If the method we tested here on a small scale proves to be effective, we are hopeful it can make a positive impact, since it is potentially much more accessible to patients than evidence-based psychotherapy and potentially more acceptable. It could present a new option for patients seeking care.”
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