Smell Function in Schizophrenia During Acute Psychosis and Correlation with Clinical Symptomatology and Length of Hospitalization

Background: While several studies have noted smell impairment in schizophrenia, it is unclear whether this impairment extends to acute psychosis and whether it is associated with more severe illness as expressed in extended hospitalization. Objectives: To evaluate the olfactory function of patients in an acute psychotic state and correlate it with clinical symptomatology and length of hospitalization. Methods: Olfactory function was assessed in 20 patients with schizophrenia in their first week of hospital admission for acute psychosis compared with matched controls. Olfaction was evaluated via three stages: threshold, discrimination, and identification of different odors utilizing the Sniffin" Sticks test battery. Results: Schizophrenia patients scored significantly lower on total smell score, discrimination, and identification abilities. A significant association was observed between hospitalization duration and total smell score and smell discrimination. No significant associations between smell and clinical symptomatology were observed. Conclusions: Study observations confirm impaired sense of smell in schizophrenia patients and suggest that smell impairment may be a potential marker of more serious illness as expressed in longer hospital stay.