Interoception, stress and physical symptoms in stress-associated diseases

The brain and peripheral bodily organs continuously exchange information. Exemplary,
interoception refers to the processing and perception of ascending information from the
body to the brain. Stress responses involve a neurobehavioral cascade, which includes
the activation of peripheral organs via neural and endocrine pathways and can thus be
seen as an example for descending information on the brain-body axis. Hence, the
interaction of interoception and stress represents bi-directional communication on the
brain-body axis. The main hypothesis underlying this review is that the dysregulation of
brain-body communication represents an important mechanism for the generation of
physical symptoms in stress-related disorders. The aims of this review are, therefore,
(1.) to summarize current knowledge on acute stress effects on different stages of
interoceptive signal processing, (2.) to discuss possible patterns of abnormal brainbody
communication (i.e., alterations in interoception and physiological stress axes
activation) in mental disorders and chronic physical conditions, and (3.) to consider
possible approaches to modify interoception. Due to the regulatory feedback loops
underlying brain-body communication, the modification of interoceptive processes
(ascending signals) may, in turn, affect physiological stress axes activity (descending
signals), and, ultimately, also physical symptoms.