LAUSR

Individuals with Post Traumatic Stress Disorder (PTSD) often present with insomnia, which may exacerbate other symptoms of the disorder. Morning Blue Light Therapy (BLT) can regulate circadian rhythms and may even improve sleep and mood in individuals with major depressive disorder. However, it is unclear whether morning BLT could also be an effective treatment for the insomnia associated with PTSD. We investigated whether 6 weeks of daily morning BLT would improve insomnia severity and symptom presentation in individuals with PTSD in comparison to a placebo condition of amber light (ALT). We hypothesized that changes in insomnia severity would correlate with improvement in PSTD symptom severity. Forty-one participants with a clinical diagnosis of PTSD were randomized to receive 6 weeks of either daily morning BLT (n=22) or ALT (n=19). Insomnia and PTSD symptom severity were evaluated at pre- and post-treatment using the Insomnia Severity Index (ISI) and the Clinician-Administered PTSD Scale (CAPS) for DSM-5, respectively. Both groups showed a significant decrease in their PTSD symptom severity (p<0.001) and insomnia severity (p<0.001) over the 6-week treatment period. However, improvement in insomnia severity significantly predicted improvements in PTSD symptom severity for the BLT group only (BLT: r =0.542, p=0.009; ALT: r=-0.095, p=0.699). The difference between the two correlation coefficients was significant (Z=-2.07, p=0.039). The results suggest that morning BLT may be effective in improving PTSD symptoms by regulating the circadian rhythm and improving sleep. While ALT also led to improved PTSD symptom severity, it appears that those changes cannot be explained by improved sleep and may have other underlying mechanisms (e.g., placebo effect). Morning BLT may be a promising adjunctive method to bolster current treatment approaches for PTSD. Because of its ease of administration, it could be easily added to ongoing treatment as usual. This approach warrants further research. US Army Medical Research and Materiel Command: W81XWH-14-1-0570