On the Neurophysiology of Delusional Disorders: Top-Bottom vs. Bottom-Up Theories

Abstract

The psychopathology of delusions has been indelibly denoted from top-bottom theories, with a very long psychiatric tradition explaining the issue as a cortical derangement. The reverse face of the entire issue has been poorly if ever, scrutinized. The role of the peripheral nervous system in the installing and the maintaining of delusive ideas and convictions, albeit elusive, need to be addressed. The hallmark of bottom-up theory relies upon distorted primary processing of peripheral stimuli, with the cortex ingenuously entering a vicious circle of false perceptions, and therefore of false beliefs. Some research suggests also that the peripheral nervous system has an intrinsic role in pain memory, thus contradicting previously cortically-oriented theories. Charles Bonnet syndrome illustrates how a distorted or a severely damaged sense of vision might produce florid psychiatric symptomatology. Apart from mere hermeneutical points of view, psychopharmacology itself will testify how difficult is to eradicate delusions with antipsychotics, classical or atypical ones. The fact that these drugs act on central synaptic pathways, and are almost neutral to the peripheral nervous transmission of signals, will be another evidence of how the periphery of the nervous system might be a starter of the delusions, instead of being a remote, inert and innocent part of the whole.