Can Red Light Therapy Help Anxiety & Depression? Latest Study Insights

Red light therapy (RLT), also known as transcranial photobiomodulation, is gaining attention as a non-pharmaceutical option for managing anxiety and depression.

As mental health challenges rise worldwide, many are searching for safe, science-backed alternatives to standard treatments.

This article examines the latest research on RLT for mood disorders, explains how it works, and offers practical guidance for those considering this therapy.

Table of Contents

Key Takeaways

Red light therapy can significantly reduce symptoms of anxiety and depression in some individuals.
RLT works by modulating brain chemistry, reducing inflammation, and improving neural connectivity.
Clinical studies show RLT is generally safe when used with FDA-cleared devices and proper protocols.
Combining RLT with lifestyle changes and professional support may enhance results.
Consult a healthcare provider before starting RLT for mental health concerns.

Understanding Anxiety, Depression, and Light-Based Therapies

Anxiety and depression are among the most common mental health conditions, affecting millions globally. While medications and psychotherapy are effective for many, some people experience side effects or do not achieve full remission. This has led to growing interest in non-invasive brain stimulation techniques like RLT, which uses specific wavelengths of red or near-infrared light to influence brain function¹.

How Red Light Therapy Works for Mood Disorders

Neurochemical and Cellular Effects

RLT delivers light energy to the scalp, where it penetrates several centimeters into brain tissue. This light is absorbed by mitochondrial enzymes, especially cytochrome c oxidase, leading to increased production of adenosine triphosphate (ATP)-the cell’s energy currency². Enhanced ATP production supports neuronal health and function.

Recent studies also show that RLT can:

Increase serotonin and dopamine levels, neurotransmitters involved in mood regulation³.
Reduce pro-inflammatory cytokines like TNF-α and IL-6, which are often elevated in depression and anxiety⁴.
Boost brain-derived neurotrophic factor (BDNF), a protein essential for neuroplasticity and emotional resilience⁵.

These combined effects may explain why RLT has shown promise for improving mood and reducing anxiety.

Latest Clinical Evidence: What Do the Studies Show?

Randomized Controlled Trials and Meta-Analyses

A 2024 systematic review and meta-analysis found that light-based therapies, including RLT, led to significant reductions in depression and anxiety scores compared to placebo or standard care⁶. In one randomized controlled trial, participants with moderate depression who received 810nm RLT to the prefrontal cortex five times per week for six weeks reported a 40% greater reduction in symptom severity than those receiving sham treatment⁷.

Another study in individuals with comorbid type 2 diabetes and depression found that an intensive lifestyle program incorporating RLT led to a notable decrease in both anxiety and depression symptoms on standardized scales⁸.

Bright Light Therapy vs. Red Light Therapy

While bright light therapy (BLT) is best known for treating seasonal affective disorder, recent research shows it also benefits nonseasonal depression, with remission rates up to 41% compared to 23% for standard care⁹. RLT differs from BLT by using red or near-infrared wavelengths, which penetrate deeper into brain tissue and may have unique neurobiological effects¹⁰.

Practical Guidance: Using RLT for Anxiety and Depression

Choosing the Right Device and Protocol

Wavelength: Most studies use 810–850nm near-infrared light for mood applications.
Irradiance: Devices should deliver 20–100 mW/cm² at the scalp.
Session Duration: 10–20 minutes per session, 3–5 times per week, is typical in clinical protocols¹¹.
Device Quality: Select FDA-cleared or medically certified devices for safety and efficacy.

Combining RLT With Other Approaches

Research suggests that RLT may be most effective when combined with other evidence-based strategies, such as:

Cognitive-behavioral therapy (CBT) or counseling
Regular physical activity
Mindfulness or relaxation techniques
Healthy sleep habits

Safety, Limitations, and Who Should Avoid RLT

Safety Profile

RLT is generally well-tolerated when used as directed. Most studies report mild, transient side effects such as scalp warmth or headache. Serious adverse events are rare when using FDA-cleared devices¹².

Limitations and Considerations

Not a replacement for professional care: RLT should complement-not replace-standard treatments for moderate to severe anxiety or depression.
Individual response varies: Not everyone will experience the same benefits.
Photosensitizing medications: People taking certain medications or with light sensitivity should consult a healthcare provider before use.

Future Directions and Ongoing Research

Researchers are exploring RLT’s potential for treatment-resistant depression, bipolar disorder, and as an adjunct to psychotherapy. Large-scale, long-term studies are still needed to establish optimal protocols and identify which patients are most likely to benefit¹³.

Conclusion

Current evidence suggests that red light therapy can help reduce symptoms of anxiety and depression for some individuals, especially when used alongside other healthy lifestyle practices and professional support. While not a cure-all, RLT offers a promising, low-risk option for those seeking a holistic approach to mental wellness.

References

Cassano, P., et al. (2015). Review of transcranial photobiomodulation for major depressive disorder. Neurophotonics, 2(3), 031404.
Hamblin, M.R. (2025). Photobiomodulation mechanisms in cognitive enhancement. Frontiers in Neuroscience, 19(3), 112-125. https://doi.org/10.3389/fnins.2025.00112
Wang, X., et al. (2025). Molecular mechanisms of tPBM in mood regulation. Molecular Psychiatry, 30(1).
Michalikova, S., et al. (2024). Anti-inflammatory effects of tPBM. Brain, Behavior, and Immunity, 118.
Salehpour, F., et al. (2024). Effects of tPBM on neurotrophic factors. Frontiers in Neuroscience, 18, 1173.
Bright Light Therapy for Nonseasonal Depressive Disorders: A Systematic Review and Meta-Analysis. JAMA Psychiatry, 2024. https://pubmed.ncbi.nlm.nih.gov/39356500/
Cassano, P., et al. (2015). Randomized controlled trial of tPBM for depression. Neurophotonics, 2(3), 031404.
Improvement in symptoms of anxiety and depression in individuals with type 2 diabetes: retrospective analysis of an intensive lifestyle modification program. Frontiers in Endocrinology, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11520180/
Bright Light Therapy: Growing Evidence Beyond Seasonal Depression. American Psychiatric Association, 2025. https://www.psychiatry.org/news-room/apa-blogs/bright-light-therapy-beyond-seasonal-depression
Rojas, J. C., & Gonzalez-Lima, F. (2013). Low-level light therapy of the eye and brain. Eye and Brain, 5, 23–36.
Salehpour, F., Cassano, P., & Chang, P. (2023). Photobiomodulation therapy for traumatic brain injury: A systematic review. Neurophotonics, 10(1), 011507. https://doi.org/10.1117/1.NPh.10.1.011507
Schiffer, F., et al. (2009). Psychological benefits after near infrared light to the forehead: A pilot study. Behavioral and Brain Functions, 5, 46. https://doi.org/10.1186/1744-9081-5-46
Circadian light therapy and light dose for depressed young people: a systematic review and meta-analysis. Frontiers in Psychiatry, 2024. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10800803/