Morning blue light therapy may improve sleep, other symptoms

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News shows that 30 minutes of blue light therapy in the morning can improve sleep and reduce the severity of PTSD symptoms. Jane Khomi/Getty Images
  • Post-traumatic stress disorder (PTSD) can occur after a person has experienced a traumatic event.
  • People with PTSD may experience flashbacks, anxiety, difficulty sleeping, and a variety of other symptoms.
  • Current treatments include psychotherapy, counseling and medication.
  • A new study has found that just 30 minutes of blue light therapy in the morning can improve sleep and reduce severity of PTSD symptoms.
  • Researchers suggest this easy-to-use therapy may increase the effectiveness of other PTSD treatments.

Most people will experience a shocking, frightening or dangerous event at some point in their lives. This can lead to a series of reactions, from which many people can recover.

But for some people, a traumatic experience will leave them with post-traumatic stress disorder (PTSD). In fact, around 6% of people in the United States will experience PTSD at some point in their lives.

PTSD can be treated with psychotherapy (talking therapy), counseling, and medication, such as antidepressants.

In a new study, researchers from the University of Arizona and Harvard Medical School have found that exposure to blue light for just 30 minutes each morning can improve sleep quality and reduce symptom severity in people with PTSD.

William D. Killgore, Ph.D., the study’s principal investigator, professor of psychiatry, psychology, and medical imaging, and director of the Social, Cognitive, and Affective Neurosciences (SCAN) Laboratory in the Department of Psychiatry at the University of Arizona College of Medicine, Tucson, said Medical News Today:

“We found that morning exposure to blue light for half an hour each day was associated with improved total sleep time and some aspects of sleep quality in our sample of patients with PTSD. This improvement sleep was also associated with an increase in the volume of a brain structure called the amygdala (which is often reduced in size in people with PTSD).

The study has just been published in Frontiers in behavioral neuroscience.

PTSD occurs when the usual short-term symptoms following a traumatic event persist for more than a month and begin to impact daily life.

PTSD symptoms May include:

  • difficulty sleeping or disturbed sleep
  • flashbacks
  • bad dreams and scary thoughts
  • avoid anything that might trigger memories of the event
  • be easily scared
  • outbursts of anger
  • negative thoughts, depression and anxiety.

Additionally, approximately 70-90% of people with PTSD report sleep disturbances, such as recurrent nightmares and insomnia.

Previous studies have shown that sleep disruption negatively affects PTSD outcomes, so improved sleep quality is often essential for recovery.

At the start of the study, 82 participants, all of whom had clinically significant PTSD, completed two full-day neurocognitive assessments as well as neuroimaging exams.

The researchers then randomly assigned the participants to one of two groups. Both groups underwent 6 weeks of home light therapy, including 30 minutes of light exposure within 2 hours of waking up and no later than 11 a.m. One group used a blue light device and the other an amber light device.

The study was double-blind – neither the participants nor the personnel in direct contact with them knew whether they were receiving blue or amber light therapy.

“We selected blue because it is the wavelength of light that is most effective in producing this shift in the biological clock,” Dr Killgore explained.

“The retina of the eye has specific receptors that respond primarily to blue wavelengths of light (which is the primary wavelength of sunlight), and these receptors project to the circadian clock of the brain (a brain structure known as the suprachiasmatic nucleus of the hypothalamus). So almost any light will work if bright enough, but blue tends to work more efficiently,” he added.

At the start of the study, researchers assessed participants’ quality of sleep, daytime sleepiness, and the frequency and severity of nightmares.

After 6 weeks, all study participants reported improved sleep quality, less disturbed sleep, and lower levels of insomnia and nightmares. But the blue light group also saw a reduction in symptoms, which was not seen in the control group.

In contrast, the Amber Light group showed a return of their original fear memories.

“We found that blue light therapy was effective in helping people retain the benefits of a simple extinguishing treatment for memories of fear. Specifically, participants were conditioned to fear a particular image by zapping them with a mildly annoying (but not painful) electric shock. Then we eliminated the fear response with a procedure called ‘extinction’ (i.e. just showing the image over and over without shock).”

– Dr. Killgore, Ph.D., study principal investigator

Dr. David A. MerrillPh.D., a geriatric psychiatrist and director of the Pacific Brain Health Center of the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, Calif., not involved in the study, said DTM:

“Exposure to blue light in the morning positively affects the brain to produce better sleep. Getting a good night’s sleep is essential to maximizing and maintaining the benefits seen with therapies for PTSD. Without sleep, you are more likely to lose the advantage.

“It is well known that exposure to morning light, whether through sunlight or a high-intensity light box, can help alleviate symptoms of depression. Blue light has also been studied in IWB [traumatic brain injury] and shown to help with cognitive recovery. This new study expands what we know about the benefits of light therapy for PTSD,” he added.

The authors propose that morning blue light therapy may effectively complement other PTSD treatments.

Despite the positive implications, however, it’s important to note that the study was small. More research is still needed before blue light therapy can be considered an effective treatment for PTSD.

“We did not design blue light therapy as a standalone therapy for PTSD, but as something to be used as an adjunct therapy to improve sleep/daily rhythmicity. [or] mood and facilitate gains made in other therapies,” Dr. Killgore said.

“Light therapy could be used to keep daily sleeping and waking rhythms in a healthier state. There are many lighting devices available that can be used for this purpose at relatively low cost.

Dr Merrill agreed and said the results were “fascinating”.

“Morning blue light exposure looks like a promising complementary therapy for those undergoing treatment for PTSD using more conventional approaches like psychotherapy,” Dr. Merrill said.

Light therapy is low risk and well tolerated. It can also work as an antidepressant, which is a 2-to-1 bonus.”