A recent study of the Whitehall II cohort in Occupational and Environmental Medicine (2013,doi:10.1136/oemed-2013-101385) finds that “organisational change affects employees’ health negatively in the short term but also that it is possible to recover from such negative effects.”

I would presume to say that the short term effect is due to the fear of losing one’s job and the recovery is the relief at having kept one’s job.