A review study published in the Journal of Biological Psychiatry (2019) indicated that training in Mindfulness Based Stress Reduction may lead to fear extinction by inducing changes in hippocampus (the brain part essential in learning new information and strategies). This de-conditioning is one of the mechanisms through which stress resilience can be fostered.
It should also be kept in mind that sustained stress or aggravation tend to foster habitual response patterns such as automatic behaviors by weakening the connection between cognitive frontal cortex and hippocampus. Sustained stress also kills neurons in hippocampus (bad for learning and deploying new strategies) and speeds up the growth of new neurons in amygdala (again bad, for most part) through release of growth factors.
