Trail Making and Olfaction in Schizophrenia: Implications for Processing Speed

Abstract

BACKGROUND: Previous research has established a relationship between smell identification deficits (SID) and particular aspects of cognitive function among patients with schizophrenia. OBJECTIVE: To expand the extant literature, we examined the relationship between SID and the Trail Making Test to determine if processing speed is related to SID. METHODS: Our sample included 60 inpatients from the New York State Psychiatric Institute's Schizophrenia Research Unit. We considered age, deficit syndrome, verbal intelligence quotient, and education in our analyses due to their documented relationship to smell identification ability. RESULTS: Trails A errors and Trails A seconds accounted for a significant amount of the variance in University of Pennsylvania Smell Identification Test scores in a regression analysis (R2=.10, P=.008 and R2=.05, P=.04). CONCLUSION: Linking neurocognition to smell identification deficits may prove to be an essential marker for schizophrenia research.