We have to have a longitudinal perspective study to really address this very important question conclusively. We don't have that. What we do have is prospective studies that kind of implicitly looked at the relationship between sleep and mental health outcomes and found that those with more sleep problems, with more mental health issues and difficulties post-deployment.... Implicitly and embedded in this data is where we see that those who don't have sleep problems during deployment, or those who have problems during deployment but can actually go back to a relatively healthy sleep pattern once they come back, are the ones at the lowest risk.
It's kind of by exclusion or by default embedded in the longitudinal studies that are available where we see that those without sleep problems or with fewer sleep problems are those who do better. In terms of intervention, it's mostly coming from clinical trials, relatively small studies, but prospectively to see if prior to deployment or during deployment or immediately after deployment, if we have everybody get sleep intervention and we follow people over time to see who uses it, if their sleep gets better, and if their sleep gets better, did we lower the risk of mental health issues.
I don't know that any studies have actually been done specifically to answer those questions.