Efficacy evaluation and facial expressions biomarker of light therapy in youths with subthreshold depression: A randomized control trial study.
Study Goal
The researchers aimed to evaluate the efficacy of light therapy on subthreshold depression (SD) in college students and explore facial expressions as an objective biomarker of treatment effectiveness.
Results Summary
Both Bright Light Therapy (BLT, 10,000 lx) and Dim Light Therapy (DLT, 200 lx) significantly improved depression symptoms and sleep quality compared to the control group, with facial expression changes supporting their efficacy. The study had a moderate sample size (121 completers) but lacked safety assessments.
Population
College students with subthreshold depression from a university in Hubei Province, China.
Effective Dosage
BLT (10,000 lx) and DLT (200 lx); frequency not specified.
Duration
Intervention period from September 13, 2021, to January 4, 2022 (exact duration unclear).
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
Bright Light Therapy (BLT) group (10,000 lx) | decrease | Depression symptom scores | college students with subthreshold depression (SD) | P < 0.001 | significantly decreased | #1 |
Bright Light Therapy (BLT) group (10,000 lx) | decrease | sleep quality scores | college students with subthreshold depression (SD) | P < 0.001 | significantly decreased | #2 |
Dim Light Therapy (DLT) group (200 lx) | decrease | Depression symptom scores | college students with subthreshold depression (SD) | P < 0.001 | significantly decreased | #3 |
Dim Light Therapy (DLT) group (200 lx) | decrease | sleep quality scores | college students with subthreshold depression (SD) | P < 0.001 | significantly decreased | #4 |
Waiting List Control (WLC) group (no intervention) | no change | Depression symptom and sleep quality scores | college students with subthreshold depression (SD) | no significant changes | no significant changes were observed | #5 |
Bright Light Therapy (BLT) group (10,000 lx) | increase | efficacy rates | college students with subthreshold depression (SD) | OR, 4.50; 95 % CI, 1.11-18.27; P = 0.035 | had higher efficacy rates than WLC group | #6 |
Dim Light Therapy (DLT) group (200 lx) | increase | efficacy rates | college students with subthreshold depression (SD) | OR, 4.17; 95 % CI, 1.04-16.79; P = 0.045 | had higher efficacy rates than WLC group | #7 |
Dim Light Therapy (DLT) group (200 lx) | increase | AU14 values (positive, negative and neutral stimuli) | college students with subthreshold depression (SD) | - | showed significant increases | #8 |
Dim Light Therapy (DLT) group (200 lx) | increase | AU26 values (neutral and negative stimuli) | college students with subthreshold depression (SD) | - | showed significant increases | #9 |
Bright Light Therapy (BLT) group (10,000 lx) | decrease | fear-related AU20 values under negative stimuli | college students with subthreshold depression (SD) | P < 0.001 | showed a significant decrease | #10 |
BACKGROUND: Simpler and more feasible light therapy protocols, and objective indicators for assessing its effectiveness is lacking. We aimed to evaluate the efficacy of light therapy on subthreshold depression (SD) among college students and explore facial expressions as an objective biomarker across different treatment groups. METHODS: From September 13, 2021, to January 4, 2022, college students with SD were recruited from a university in Hubei Province, randomly assigned to Bright Light Therapy (BLT) group (10,000 lx), Dim Light Therapy (DLT) group (200 lx), or Waiting List Control (WLC) group (no intervention). Self-reported questionnaire and facial expressions were assessed for all participants before and after intervention. Repeated measures ANOVA and logistic regression were conducted to compare baseline and post-intervention differences among three groups. RESULTS: 135 participants were enrolled and 121 participants completed the study. Depression symptom and sleep quality scores significantly decreased in both BLT and DLT groups (P < 0.001), while no significant changes were observed in WLC group. BLT (OR, 4.50; 95 % CI, 1.11-18.27; P = 0.035) and DLT group (OR, 4.17; 95 % CI, 1.04-16.79; P = 0.045) had higher efficacy rates than WLC group. For facial expressions, DLT group showed significant increases in two happy-related facial action units (AU) including AU14 values (positive, negative and neutral stimuli) and AU26 values (neutral and negative stimuli). BLT group showed a significant decrease in fear-related AU20 values under negative stimuli (P < 0.001). CONCLUSION: Light therapy improves depressive symptoms and sleep quality in individuals with SD, and facial expressions can serve as an objective biomarker to support its effectiveness.