stay updated with our newsletter

Blue Light Therapy Helps PTSD Sufferers

frontiers in behavioral neuroscience

People with post-traumatic stress disorder (PTSD) experienced better sleep, a reduction in the severity of symptoms, and more effective treatments after exposure to blue light therapy, according to a new study in Frontiers in Behavioral Neuroscience.

Sleep is crucial for maintaining physical and mental health, and over time, inadequate sleep can impact all aspects of life with serious implications for long-term health, relationships, and cognitive abilities such as learning and healing.

The influence of sleep disruption on PTSD symptom severity is well established. Those who seek treatment to allay their PTSD symptoms often face a vicious cycle where poor sleep interferes with the effectiveness of treatments, negating any lessening of symptoms, which in turn contributes to sleep disruptions. To reduce and eliminate the emotional impact of traumatic memories, the patient needs quality sleep to integrate healing mechanisms achieved through cognitive or exposure therapy treatments.

“This research is exciting and unique because it points to an easy-to-use method for helping those with PTSD to retain the benefits of therapy long after the treatment ends,” said psychiatry professor William “Scott” Killgore, PhD, director of the Social, Cognitive and Affective Neuroscience (SCAN) Lab at the University of Arizona College of Medicine and senior author on the paper, “Morning blue light treatment improves sleep complaints, symptom severity, and retention of fear extinction memory in post-traumatic stress disorder.”

Study Details

Dr. Killgore and the SCAN Lab team conducted a comprehensive assessment of daily morning blue-wavelength light exposure on individuals with clinically significant levels of PTSD. The goal was to ascertain if blue light therapy would help improve sleep and PTSD symptoms and sustain learned fear extinction memories, an analog of therapeutic treatment for trauma.

Study participants committed to 30 minutes of morning light exposure daily for six weeks, with half of the participants using blue-wavelength light and half using amber light. Researchers examined the neurobiological, autonomic, and behavioral outcome changes during the study.

The 43 participants who received blue light therapy not only demonstrated significant improvements in the severity of their PTSD symptoms but also reported improvements in sleep and showed increased retention of fear extinction memories. In comparison, the 39 study participants who received amber light did not show the same retention of the extinction memories but rather showed a return of the original fear memories.

“While the limitations of the research include its modest sample size and difficulties monitoring compliance, the possibilities of utilizing a treatment that is relatively simple, drug-free and inexpensive can offer hope for the large population of people living with the intense challenges of post-traumatic stress disorder,” Dr. Killgore said.


The present study examined the association between 6 weeks of daily morning blue-wavelength light relative to amber-wavelength light placebo treatment. Overall, we found support for the hypothesis that improvements in sleep would be linearly correlated with improvements in PTSD symptom severity. Furthermore, the findings from the fear extinction task support the global hypothesis that BLT improves autonomic reactivity and brain function in a manner that aids in fear extinction/safety memory, even across longer durations of time than this type of paradigm is typically employed. This is especially important, as safety learning is critical to recovery and several prominent evidence-based treatments for PTSD are based extensively on principles of fear extinction. These results suggest that BLT is a promising non-pharmacological intervention that may potentially facilitate the retention of treatment gains from exposure-based therapies by resetting the circadian clock and improving sleep in a manner that promotes the consolidation of extinction memory. Future work will need to identify the clinical significance of these outcomes as well as their temporal effect, but these results suggest that BLT may be useful for improving sleep and consolidating safety learning outcomes in a manner that promotes the reduction of sleep-related complaints and PTSD symptoms.



Weekly round-up, access to thought leaders, and articles to help you improve health outcomes and the success of your practice.