Five years is actually not a long time for science to understand a process as complex as the pathways of the oil after a large spill. Some of the impacts of the Deepwater Horizon spill on the marine life and ecosystems of the Gulf of Mexico will only become visible in future years. We use oil products daily.
First the researchers examined the effects of lowering cortisol to below a normal (or baseline) level. Then they compared the effects of low, medium, high, and very high cortisol levels in patients undergoing cardiac surgery, a procedure that causes a lot of inflammation.
I think the real root of problem, with high adrenaline and cortisol, is that they are often caused by a reaction to histamine, which in turn, is a reaction to chronic inflammation.