Well said, bws48. Lipid metabolism, blood pressure regulation, depression and a host of other commonly treated chronic medical problems are associated with the stressors of every-day life, related to adrenaline secretion and stress responses better suited to dealing with saber-tooth tiger attacks than traffic jams and workplace annoyance. Survival emergencies may eliminate the stressors for which we are poorly adapted and which cause illness, and substitute stressors for which we are better adapted. This has an organizational parallel: every ER I have ever worked in worked better in a crisis (mass casualty incident, weather-related emergency, that sort of thing) than it worked day-to-day. Crises occasionally have an unanticipated upside.