Brain imaging studies have gradually revealed the mechanisms of stress-induced mental and physical symptoms and the mechanisms through which they can be improved by treatment. This article outlines the brain regions related to these phenomena. Because the enhancement of sympathetic nervous activity caused by stress is known to be related to mental and physical symptoms, we attempted to clarify the relation of the activities of the anterior cingulate cortex and the insular cortex, both of which have been reported to be related to stress-induced mental and physical symptoms, to sympathetic nerve activity caused by stress. In neural change by psychotherapy, our studies clarified that activation of the ventral striatum (reward system) and the insula cortex was enhanced by perceiving active listening and that the impression of episodes was changed more positively by perceiving active listening. We also clarified that relief of anger by cognitive reappraisal is related to activation of the anterior cingulate cortex. In addition, a meta-analysis of brain imaging studies based on a stress coping method that used mindfulness or cognitive therapy reported that brain activation and the cerebral volume of the anterior cingulate cortex and the insula cortex were increased after treatment. Thus, it has been well documented that stress-induced mental and physical symptoms are associated with the anterior cingulate cortex and the insular cortex and that psychotherapy results in structural and functional changes in these brain regions. Consequently, we can infer that mental and physical symptoms are improved through the change of these brain regions.