"The central suggestion regarding the 'vaccine' effect seemed to be buried a bit in the article (unless I missed something in skimming), but it is the actual ne

"The central suggestion regarding the 'vaccine' effect seemed to be buried a bit in the article (unless I missed something in skimming), but it is the actual new information, which is interesting and heartening." You are correct, this is a new finding. It does not, however, come from the study looking at soldiers. In that study, ketamine was actually given after stress (not as a 'vaccine'). Those researchers also failed to replicate that effect when they looked a larger group of soldiers. The first study was done in 2008 and the second one was done in 2014. Believe me, if they had found a protective effect in humans 7 years ago, you would have heard about it by now. The research that actually shows the ketamine might be a 'vaccine' has all come out this year (2015). And, so far, it's all only in mice. The scientific publication referred to in the Nautilus article is "Ketamine as a Prophylactic Against Stress-Induced Depressive-Like Behavior": http://www.biologicalpsychiatryjournal.com/article/S0006-3223(15)00360-1/abstract http://www.biologicalpsychiatryjournal.com/article/S0006-322.... At least two other research teams at other universities (FSU & UC-Boulder) have independently also found similar effects, but none of that is published yet (though it was presented this year at the national Society for Neuroscience conference). In other words: yes, it's new. Additionally, neuroscientists at Mt. Sinai, the NIMH, and UC-Boulder (among others) have found that bacteria and immune cells might also be used to 'vaccinate' against stress. Again, most of that research--though not all of it--is still not published yet, and has only been presented at conferences so far.