ABSTRACT
This chapter explores some peripheral systems of the body that are involved in psychopathology. The sympathetic medullary system appears to serve the function of activation of psychological states for "defensive go" in the periphery and facilitate fight/flight behaviour. It prepares the organism to deal with threat and regulates a number of physiological processes that would facilitate dealing with threat. The parasympathetic nervous system uses the neurotransmitter ACh and tends to oppose the sympathetic system, acting like a braking system. The neurobiological control of hypothalamic-pituitary-adrenal-cortical system (HPAC) is highly complex and is influenced by a multitude of neurotransmitters. The HPAC is probably more involved in long-term states of stop and possibly has a significant impact on "state" processes. Current research suggests that various interpretations such as low expectations of success, low self-esteem and expectations of defeat and depression activate the HPAC system. The dexamethasone suppression test (DST) studies show a relation between severity, possibly psychotic states and hypercortisol secretion.
