Bright Light Therapy Effective Adjunct Treatment for Nonseasonal Depression

Bright light therapy is an effective adjunctive treatment among patients with nonseasonal depressive disorders, according to study findings published in JAMA Psychiatry.

Bright light therapy is an established adjunctive treatment modality in seasonal depressive disorders. However, its clinical utility in nonseasonal depressive disorders remains unclear.

Investigators from Federal University of Mato Grosso and Dante Pazzanese Institute of Cardiology in Brazil conducted a systematic review and meta-analysis of relevant randomized controlled trials (RCTs). Bright light therapy was defined as white light at 5000 to 10,000 lux for 30 minutes and longer.

The primary outcome was response to treatment and remission of symptoms, whereas secondary outcomes included depression scale ratings.

The analysis included a total of 11 RCTs published between 2005 and 2024. The study bright light therapy interventions were at 10,000 lux (n=9), 7000 lux (n=1), and 5000 lux (n=1) for 30 to 60 minutes a day. The control interventions included red light therapy at between 50 to less than 500 lux (n=8), sham bright light therapy with a negative ion generator (n=2), and antidepressant monotherapy (n=1).

The studies included patients with major depressive disorder (MDD; n=6), bipolar depressive disorder (n=3), unipolar MDD (n=1), and both MDD and bipolar disorder (n=1). The pooled study population comprised 858 patients who were predominately women (75.6%). Overall, 52.3% of patients received the bright light therapy intervention.

Patients who received bright light therapy vs control intervention had a higher rate of remission (40.7% vs 23.5%) and treatment response (60.4% vs 38.6%). Bright light therapy was associated with remission (odds ratio [OR], 2.42; 95% CI, 1.50-3.91; I², 21%; P <.001) and response to treatment (OR, 2.34; 95% CI, 1.46-3.75; I², 41%; P <.001).

After stratification by follow-up duration, bright light therapy vs control was associated with remission at a less than 4-week follow-up (OR, 3.59; 95% CI, 1.45-8.88; I², 0%; P =.005) and more than 4-week follow-up (OR, 2.18; 95% CI, 1.19-4.00; I², 47%; P =.01). Response to bright light therapy was also associated with shorter (OR, 3.65; 95% CI, 1.81-7.33; I², 35%; P <.001) and longer (OR, 1.79; 95% CI, 1.01-3.17; I², 32%; P =.04) follow-ups.

Bright light therapy vs control had a significant effect on Hamilton Rating Scale for Depression (HAM-D) scores (mean difference [MD], -1.44; 95% CI, -2.40 to -0.48; I², 0%; P =.003) but not on Montgomery-Åsberg Depression Rating Scale (MADRS) scores (MD, 0.36; 95% CI, -2.60 to 3.31; I², 23%; P =.81) or Clinical Global Impressions Scale (CGI) scores (MD, -0.06; 95% CI, -0.29 to 0.16; I², 0%; P =.56).

Study authors concluded, “Our study results suggest that [bright light therapy] offers significant benefits as an adjunctive treatment for these conditions. In addition, different follow-up times assessed in the subgroup analysis suggest that [bright light therapy] not only increases remission and response rates but also accelerates the time to respond to initial treatment.”

The major limitation of this study was the exclusion of a diagnosis-specific subgroup analysis due to the small sample sizes.

This article originally appeared on Psychiatry Advisor