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

The authors investigated the potential effectiveness of light therapy as an augmentation treatment for depression among active duty service members.

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.

The study was conducted at Walter Reed Army Medical Center's Psychiatry Continuity Service.

Zung Self-Rating Depression Scale collected at baseline, after five consecutive daily light sessions, and one week later.

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.

The post hoc analysis hints at the possibility of a reduction in depression during the active phase of light treatment.