Project Summary

Richard Keefe, Ph.D. (Independent Investigator 2003) of Duke University, notes that olfactory function appears to have great potential for revealing deficits that may help predict psychosis in individuals early in the disorder and may also provide information about changes in neuronal growth that may occur at the onset of psychosis. Changes in the growth of connections between neurons have been found to be associated with performance on some aspects of neurocognitive function, such as learning and olfaction (the perception, identification, and memory of odors). Patients with schizophrenia have impaired olfactory function and reduced volume of the olfactory bulb, which is highly correlated with olfactory sensitivity. This brain region is particularly important to hypotheses about neuronal growth in schizophrenia, as the growth of neurons in the olfactory bulb, unlike other brain regions, continues throughout adult life. Thus, olfactory functioning may be particularly susceptible to changes in neuronal growth. Further, very recent data suggests that olfactory identification deficits may predict which individuals at ultra-high risk for psychosis will eventually develop schizophrenia. Previous research has been limited to the use of standard measures of odor identification, and has not involved a comprehensive assessment of olfactory function which may identify specific deficits related to specific brain systems that become impaired at the onset of psychosis. Dr. Keefe will investigate the hypothesis that changes in olfactory function, which may reflect alterations in neuroplasticity, occur in direct temporal relation to the onset of psychosis. He believes subjects with severe prodromal (initial) symptoms for schizophrenia will demonstrate poorer performance than controls on measures of olfactory function from a comprehensive olfactory assessment, and that the greater the severity of olfactory deficits, the greater the risk these individuals will have for developing a schizophrenia spectrum disorder.

Program Area: SCHIZOPHRENIA/PSYCHOTIC DISORDERS\Schizophrenia

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