Research on Light Therapy and Anxiety
Anxiety can stem from a range of biological and environmental factors, and its symptoms often interfere with daily life. Fortunately, research in transcranial photobiomodulation (tPBM) is showing promising results for reducing anxiety.
Comorbidities of Anxiety Disorders
Anxiety commonly occurs alongside many other conditions, both psychological and physical. Some common comorbidities include (Anxiety & Depression Association of America, 2021):
- ADHD (attention deficit/hyperactive disorder)
- Autism
- BDD (body dysmorphic disorder)
- Chronic pain
- Chronic Illness
- Eating disorders
- Fibromyalgia
- Headaches
- Health anxiety
- Hoarding disorder
- Irritable bowel syndrome (IBS)
- Sleep disorders
- Substance use disorders
What Causes Symptoms of Anxiety?
- Life Experiences - Various studies reinforce the idea that experiencing adverse or traumatic life events significantly increases the likelihood of developing anxiety disorders (Miloyan et al., 2021).
- Epigenetics - Epigenetic changes, including DNA methylation and histone modifications can be triggered by stress or trauma and can affect brain function in ways that increase anxiety risk (Persaud & Cates, 2023).
- Mitochondrial Dysfunction - Disruption in mitochondrial energy metabolism, potentially involving pathways like AMPK/SIRT1, is proposed as a foundational mechanism underlying anxiety disorders (Zhao et al., 2023).
- Imbalance of Neurotransmitters - Irregularities in various neurotransmitters are found in people with anxiety disorders including serotonin (5-HT) and norepinephrine (Martin et al., 2013).
- Neuroanatomical Considerations - Etkin & Wager (2007) conducted a meta-analysis of fMRI studies and found amygdala hyperactivation across multiple anxiety disorders, including social anxiety, PTSD, and specific phobias.
Scientific Insights - PBM’s Applications for Anxiety
FAQs
How many PBM sessions will I need?
Benefits can often be noticed within a few sessions, especially related to sleep and mental clarity. For cognitive improvements, consistent use over several weeks or months is typically recommended. As AD is often referred to as a neurodegenerative disease with genetic components, incorporating light therapy as a regular lifestyle habit can support overall brain health and give your brain the best chance to stay at its most performing level over time.
Is PBM safe?
Yes. PBM is FDA-cleared for various applications and has a strong safety profile. It’s non-invasive, painless, and has no known serious side effects when used as directed.
What results can be expected and when?
Types of results and their timelines vary depending on the individuals. However, a combination of research and anecdotal evidence from providers suggests some expected results to be the following: improved language capabilities, improvements in emotional regulation, decreased repetitive behaviours, and improved social skills/engagement. While some clients may see results very quickly, others may take a few months.
What is mitochondrial dysfunction?
Mitochondrial dysfunction is a term that encapsulates dysfunction in various operations of the mitochondria. With mitochondria being the main energy producers of the cell, dysfunction can lead to reduced ATP (energy) production, increased oxidative stress, and difficulty maintaining healthy cell function. When mitochondria can’t keep up with the body’s energy demands or fail to remove damaged components, it can affect brain function, muscle strength, immune response, and overall vitality. Mitochondrial dysfunction is linked to many conditions, including fatigue, neurodegeneration, and metabolic disorders (Zong et al., 2024).
References
Anxiety and Depression Association of America. (2021, April 27). Co-occurring disorders: Anxiety and related conditions. Retrieved September 2, 2025, from https://adaa.org/understanding-anxiety/co-occurring-disorders
leveland Clinic. (2024, July 3). Anxiety disorders: Causes, symptoms, treatment & types. Retrieved [your retrieval date], from Cleveland Clinic Health Library website: https://my.clevelandclinic.org/health/diseases/9536-anxiety-disorders#symptoms-and-causes
Eshaghi, E., Sadigh-Eteghad, S., Mohaddes, G., & Rasta, S. H. (2019). Transcranial photobiomodulation prevents anxiety and depression via changing serotonin and nitric oxide levels in brain of depression model mice: A study of three different doses of 810 nm laser. Lasers in Surgery and Medicine, 51(7), 634–642. https://doi.org/10.1002/lsm.23082
Etkin, A., & Wager, T. D. (2007). Functional neuroimaging of anxiety: A meta-analysis of emotional processing in PTSD, social anxiety disorder, and specific phobia. American Journal of Psychiatry, 164(10), 1476–1488. Helali, H., Samani, N., Tabeie, F., Eiliaei, S., & Kheradmand, A. (2025). The effectiveness of transcranial photobiomodulation therapy (tPBM) on reducing anxiety, depression, and opioid craving in patients undergoing methadone maintenance treatment: A double-blind, randomized, controlled trial. BMC Psychiatry, 25(1), Article 94. https://doi.org/10.1186/s12888-025-06555-3
Kerppers, F. K., Gonçalves Dos Santos, K. M. M., Ribeiro Cordeiro, M. E., da Silva Pereira, M. C., Barbosa, D., Pezzini, A. A., Cunha, L. F., Fonseca, M., Bragnholo, K., Inoue Salgado, A. S., & Kerppers, I. I. (2020, March 7). Study of transcranial photobiomodulation at 945-nm wavelength: Anxiety and depression. Lasers in Medical Science, 35(9), 1945–1954. https://doi.org/10.1007/s10103-020-02983-7
Martin, E. I., Ressler, K. J., Binder, E., & Nemeroff, C. B. (2009). The neurobiology of anxiety disorders: Brain imaging, genetics, and psychoneuroendocrinology. Psychiatric Clinics of North America, 32(3), 549–575. https://doi.org/10.1016/j.psc.2009.05.004
Persaud, N. S., & Cates, H. M. (2023). The epigenetics of anxiety pathophysiology: A DNA methylation and histone modification focused review. eNeuro, 10(4), ENEURO.0109-21.2021. https://doi.org/10.1523/ENEURO.0109-21.2021
Zhao, A.-R. (2023). Stress can affect mitochondrial energy metabolism and AMPK/SIRT1 signaling pathway in rats. Brain Research Bulletin, 194, 110770. https://doi.org/10.1016/j.brainresbull.2023.110770
