A Light in the Dark: Red Light Therapy for Depression

According to a global report published by the World Health Organization, more than 264 million people were suffering from depression in 2017. This number rose dramatically during the COVID-19 pandemic, with 4 in 10 US adults reporting symptoms of anxiety or depressive disorder, up from 1 in 10 in 2019. It’s becoming increasingly clear that depression is not just an individual problem, but a global public health issue, as well, highlighting the need for effective, affordable treatment. With this in mind, researchers are beginning to set their sights on red light therapy, thanks to its proven effectiveness at treating myriad other health issues and its history of being well-tolerated and without adverse effects. Let’s explore what the latest research is saying about red light therapy for depression.

What is Depression? Symptoms and Treatment

According to the American Psychiatric Association, depression, also known as major depressive disorder or MDD, “is a common and serious medical condition that affects how you feel, the way you think and how you act”. While many associate the condition with sadness, it has a host of other symptoms that can significantly impair a person’s life and wellbeing. Some of these include:

  • Lack of motivation or loss of interest in activities once enjoyed
  • Sleep disturbances (insomnia or sleeping too much)
  • Irritability or angry outbursts
  • Lack of energy or extreme fatigue
  • Lack of appetite or increased food intake
  • Anxiety or restlessness
  • Feelings of worthlessness
  • Difficulty thinking or concentrating
  • Thoughts of death or suicide
  • Unexplained physical symptoms (aching muscles and joints or headache)

The number and severity of symptoms can vary from one individual to the next. Typical treatment for depression involves medication (there are hundreds of medications used to treat the condition, and it can take a lot of trial and error to find one that works for the individual), therapy (cognitive-behavioural or psychodynamic therapy, for instance), or a combination of both. 


Perhaps you’re looking at the list above thinking, “This sounds like me”. Or maybe you have a diagnosis and you’re looking for an effective way to supplement your current treatment. Whatever your situation, it’s crucial to embark on this journey with your doctor, as self-diagnosis and unsupervised treatment can have dire consequences. 

Treating Depression With Red Light Therapy: Current Research

  • A 2009 study evaluated the effects of a single red light therapy treatment on 10 patients with MDD. Patients received, in random order, 4 minutes of treatment to the left forehead and right forehead as well as placebo treatment to the same areas. Depression and anxiety symptoms were measured immediately after each treatment, and again after 2 and 4 weeks. Participants showed significant improvement on the positive and negative affect scale (PANAS) immediately after exposure to treatment, but not after exposure to placebo. Six out of 10 patients were in remission two weeks post-treatment.
  • In a 2015 study, researchers evaluated the effectiveness of red light therapy on traumatic brain injury (TBI) symptoms. A single patient received 20 near-infrared light treatments over 2 months. Symptoms were measured using clinical examination and a patient diary system. The patient showed significant improvements in depression, anxiety and insomnia, and cognition and quality of life were improved as well.
  • A 2015 double-blind, randomized study evaluated the effects of red light therapy compared to a sham treatment on 4 patients suffering from MDD. Over 8 weeks, participants underwent 3 near-infrared treatment sessions through the forehead, followed by 3 sham treatments. Researchers used the Hamilton depression rating scale (HAM-D17) to measure degree of depression at weeks 4, 5, 6, 7, and 8. The mean HAM-D17 scores were significantly lower at weeks 6, 7, and 8, indicating remission. Safety and tolerance to treatment were also highlighted by the researchers.
  • A 2016 clinical trial examined red light therapy’s effectiveness alongside attention bias modification (ABM) on 51 patients suffering from depression. ABM is a cognitive intervention designed to reduce negative attentional bias (the tendency to focus on negative elements while ignoring positive ones). Participants received ABM before and after red light therapy treatment, administered to the right forehead or left forehead, or a sham treatment. Patients who received treatment in the right forehead showed greater improvement among those who responded to ABM than those who received the left forehead treatment or the sham. This shows an interesting correlation between the two treatments.
  • A 2016 literature review focused on studies examining the link between MDD and certain biological processes, namely brain metabolism, inflammation, neurogenesis (the formation of new neurons), and oxidative stress. The researchers concluded that red light therapy is a promising treatment for depression, and may also be effective for treating comorbid anxiety disorders and suicidal ideation.
  • In a 2017 study, 39 participants suffering from depression received multi-watt near-infrared light therapy (between 8 and 34 sessions, depending on patient improvement, at 9-12 minutes each). Ninety-two percent (92%) of patients showed a dramatic reduction in depression symptoms, with many showing significant improvement after only 4 sessions. Patients were mostly still in remission 2, 6, and 12 months post-treatment.
  • In a similar 2018 clinical trial, 20 subjects suffering from MDD were administered transcranial red light therapy or a sham treatment for 20-30 minutes twice a week for 8 weeks. HAM-D17 was used to measure the degree of depression in participants throughout the treatment. After 8 weeks, HAM-D17 scores were significantly lower in the treatment group compared to the sham group.
  • A 2018 case study evaluated the effectiveness of red light therapy on a 76-year-old woman with anxious depression complicated by Takotsubo Cardiomyopathy, a heart condition that develops in response to emotional distress (also known as broken heart syndrome). The patient was irradiated with near-infrared light first through both nostrils and then through the forehead. While there was no significant reduction of depression symptoms with the nostril treatment, daily forehead irradiation proved effective at reducing symptoms of depression and anxiety. The patient’s overall functioning was improved as well. 

While there is a clear need for more research on the topic, particularly studies with larger sample sizes to enable us to better extrapolate the findings to the general public, the consensus is that red light therapy has great potential to be a safe and effective alternative or supplemental treatment to antidepressant medication.


Plus, red light therapy has loads of other benefits, many of which can help treat comorbid conditions or secondary symptoms, for example sleep disturbances (a common problem for those with depression) and physical symptoms such as muscle and joint pain and headache. 


Talking to your doctor about red light therapy could be the first step toward improving your condition, and your quality of life. In the meantime, check out our blog to see the multitude of ways red light therapy can improve your life, and see why Rouge Red Light Therapy devices are among the most powerful and affordable on the market. Get started on the road to better health with Rouge today!

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