Watch this National Geographic and Stanford University documentary on how stress kills your brain cells and affects hippocampus which is responsible for your learning and memory (from 25 min of the documentary). “Stress is not a state of mind… it’s measurable and dangerous, and humans can’t seem to find their off-switch.” says author and award-winning neurobiologist Robert Sapolsky in the documentary Stress: Portrait of a Killer.
Research done on lab rats subjected to chronic stress suggests their brain cells were dramatically smaller than the control group of normal rats.
Normal vs stressed brain cells of lab rats