A neurological disorder generally presenting itself in males aged 18-40 as a result of deploying to environments that are so hot the brain cooks inside of a helmet that is bombarded by high frequency radio waves and X-ray radiation while simultaneously trying to figure out exactly what the mission is. The people who are handicapped by this syndrome return noticably impaired in both mental and physical capabilities.
My uncle has Deployment Driven Down Syndrome (DDDS). He spent 9 months looking at the same patch of desert for 8 hours a day during OSS while running a backscatter.