Effectiveness of light therapy for depression among active duty service members: A nonrandomized controlled pilot trial

Objective: The authors investigated the potential effectiveness of light therapy as an augmentation treatment for depression among active duty service members. Design: This pilot study recruited active duty service members deployed to an area of combat operations. Enrollment was offered to service members scoring 50 or greater on the Zung Self-Rating Depression Scale. The authors implemented a systematic sampling technique randomly assigning the first subject and then alternating each subsequent subject to either a reference group which received the usual standard of care plus light therapy at 10,000 lux or a control group which received the usual standard of care and light therapy at 50 lux. Both groups received 90 min light sessions for five days. Setting: The study was conducted at Walter Reed Army Medical Center's Psychiatry Continuity Service. Main Outcome Measure: Zung Self-Rating Depression Scale collected at baseline, after five consecutive daily light sessions, and one week later. Results: A repeated measures analysis of variance (RM ANOVA) was conducted to examine the change in Zung Depression results which showed a significant main effect for time F(2, 21) = 5.05, p < 0.02, indicating that depression scores reduced over time for both participant groups. Post hoc comparisons (with Bonferroni correction) demonstrated that the post-treatment Zung score was significantly lower indicating less depression than the baseline Zung score (p < 0.004) and there was a statistical trend (p < 0.05) for depression scores to be reduced halfway through the study in the treatment group. Conclusion: The post hoc analysis hints at the possibility of a reduction in depression during the active phase of light treatment. (C) 2011 Published by Elsevier Ltd