Published in the December 20 issue of the Journal of Neuroscience... new findings from an NIH-funded study conducted by researchers at the National Institute of Mental Health (NIMH) finds that over time, new experiences can actually re-wire the brain to develop better resiliency to stress.

This from the NIMH press office:

It's long been known that experiencing control over a stressor immunizes a rat from developing a depression-like syndrome when it later encounters stressors that it can't control. Now, scientists funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health (NIH), have unraveled the workings of the brain circuitry that inoculates against such hard knocks -- the circuitry of resilience.

Control not only activated the brain's executive hub, the prefrontal cortex, but also altered it so that it later activated even when the stressor was not controllable. This activation turned off mood-regulating cells in the brainstem's alarm center. The immunizing effect was so powerful that even a week later, when confronted with an uncontrollable stressor, the cells behaved as if the stressor was controllable and the rat was protected.

"Lack of control over stressful life experiences has been implicated in mood and anxiety disorders," noted NIMH Director Thomas Insel, M.D. "Understanding how the brain encodes the experience of control to protect against such adverse consequences should help us develop better treatments for these disorders."

Rats exposed to uncontrollable stress develop a syndrome similar to depression. and post-traumatic stress disorder (PTSD), in which they lose the ability to learn how to escape stressors and behave more fearfully.

"Perceived control, or coping, can buffer individuals against the negative emotional and physiological impact of stress," said [lead researcher] Maier. "Enhancing the cortex's control over brainstem and other stress-responsive structures appears to be critical for preventing and treating mood and anxiety disorders."