A Phenomenological and Neurophysiological Study of Schizophrenic Hallucinations with an Original Hypothesis for the Etiology and Pathogenesis of Schizophrenia Based on the Mesolimbic Dopamine System

Abstract

Schizophrenic hallucinations were studied with regard to their phenomenology. A comparison was made with the "model psychoses"-sleep, hallucinogen psychosis, amphetamine psychosis, and the organic psychoses (especially temporal lobe epilepsy). The dopamine theory of schizophrenia was presented, and then the author's own hypothesis for a neurophysiological mechanism for schizophrenic hallucinations was introduced. This hypothesis is an attempt to explain both the etiology and pathogenesis of schizophrenia. It is based on the dopamine theory, and in particular the mesolimbic (A10) dopamine system. Electrical brain stimulation studies, which evoke experiential hallucinations, along with experimental results showing that these hallucinations are dependent upon the subject's psychological state have caused the author to label this phenomenon contextual hallucinations. Recently, dopamine nerve terminals have been discovered in the limbic cortex and it is known that the neuroleptic drugs antipsychotic effects are in the mesolimbic dopamine system. These findings have led the author to propose that schizophrenic hallucinations are very similar to contextual hallucinations and they are elicited by an improper balance of dopamine in the mesolimbic system. It is thought that stress might psychosocially activate this mechanism. The author also suggests that the additional symptoms of schizophrenia are secondary and peripheral to hallucinations.