Deficit Symptomatology of Schizophrenia Is Associated with Attenuated Taste Identification: Findings from a Cross-Sectional Study

Schizophrenia is the subject of many studies. There have been reports of taste disturbances in mental disorders. We found a possible relationship between deficit symptoms of schizophrenia and the dysgeusia of monosodium glutamate (MSG). Dysgeusia is a disorder that distorts the sense of taste. People describe all foods as tasting sweet, sour, bitter, or metallic. We aimed to verify whether the level of MSG taste perception may be related to the severity of deficit symptoms. MSG detection threshold was assessed via sublingual administration of three fluid samples containing MSG or water. The MSG samples had different concentrations in each sample. The task was to indicate which of the samples contained MSG, determine the intensity of the taste, and assess the taste as pleasant, unpleasant, or neutral. The study group included 200 patients diagnosed with paranoid schizophrenia according to ICD-10. We found a significant negative correlation between mean intensity of taste and the number of deficit symptoms. The symptoms of taste disturbances reported by the patient should be monitored by clinicians and differentiated between the actual deficits in the field of taste perception and the taste hallucinations as a symptom of psychosis. It is important to continue research in this area.