FPIN's Clinical Inquiries

Does Light Therapy Decrease Depression in Older Adults?


Am Fam Physician. 2021 Oct ;104(4):417-418.

Clinical Question

Does light therapy decrease depression in older adults without seasonal depression?

Evidence-Based Answer

Light therapy appears to be mildly effective in treating depression in older adults, but ideal wavelength, intensity, and length of treatment are unknown. (Strength of Recommendation [SOR]: B, based on a systematic review of randomized controlled trials [RCTs] with heterogeneity and extrapolated from systematic reviews of RCTs of adults of all ages.) In adults, bright white light exposure in the mornings for less than 60 minutes may be most effective. (SOR: B, based on a systematic review of RCTs.)

Evidence Summary

A 2018 systematic review and meta-analysis of six RCTs (N = 359) examined the effectiveness of light therapy among patients older than 60 years with nonseasonal depression.1 The trials compared light therapy (of varying wavelength, intensity, and duration) to either dim red or white light, nothing, or usual therapy. Trials were conducted for four weeks (three trials), three weeks (one trial), or no more than two weeks (two trials). The pooled results of all trials found that geriatric depression symptoms improved more with a small to moderate effect in the light therapy groups compared with the control groups (standardized mean difference [SMD] = 0.45; 95% CI, 0.14 to 0.75). Subgroup analysis by length of intervention revealed no statistically significant differences between treatment and control groups at two weeks (two trials; n = 117; SMD = −0.18; 95% CI, −0.54 to 0.18; I2 = 0%), three weeks (two trials; n = 165; SMD = 0.38; 95% CI, −0.36 to 1.13; I2 = 83%), or four weeks (three trials; n = 179; SMD = 0.25; 95% CI, −0.05 to 0.54; I2 = 0%). In all six trials, there were no significant adverse reactions in the treatment group. The treatment and control groups did not differ in the rates of adverse reactions reported. Because of limited available evidence, the authors were not able to make conclusions regarding the ideal wavelength, intensity, or duration

Author disclosure: No relevant financial affiliations.

Address correspondence to Corey Lyon, DO, at corey.lyon@cuanschutz.edu. Reprints are not available from the authors.


show all references

1. Zhao X, Ma J, Wu S, et al. Light therapy for older patients with non-seasonal depression: a systematic review and meta-analysis. J Affect Disord. 2018;232:291–299....

2. Tao L, Jiang R, Zhang K, et al. Light therapy in non-seasonal depression: an update meta-analysis. Psychiatry Res. 2020;291:113247.

3. Gelenberg AJ, Freeman MP, Markowitz JC, et al.; Work Group on Major Depressive Disorder; American Psychiatric Association. Practice guideline for the treatment of patients with major depressive disorder. 3rd ed. 2010. Accessed July 30, 2020. https://psychiatryonline.org/pb/assets/raw/sitewide/practice_guidelines/guidelines/mdd.pdf

4. American Geriatrics Society 2015 Beers Criteria Update Expert Panel. American Geriatrics Society 2015 updated Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2015;63(11):2227–2246.

Clinical Inquiries provides answers to questions submitted by practicing family physicians to the Family Physicians Inquiries Network (FPIN). Members of the network select questions based on their relevance to family medicine. Answers are drawn from an approved set of evidence-based resources and undergo peer review.

The complete database of evidence-based questions and answers is copyrighted by FPIN. If interested in submitting questions or writing answers for this series, go to http://www.fpin.org or email: questions@fpin.org.

This series is coordinated by John E. Delzell Jr., MD, MSPH, associate medical editor.

A collection of FPIN's Clinical Inquiries published in AFP is available at https://www.aafp.org/afp/fpin.



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