Implications of olfactory agnosia for understanding sex differences in schizophrenia.

In our studies, 50 percent of the male patients with schizophrenia have an olfactory agnosia. This finding is of interest because the olfactory neuroanatomical network involves brain regions found to be abnormal in patients with schizophrenia, and this olfactory deficit appears to be sex dependent. This article reviews conceptual models for assessing olfactory function, describes the neuroanatomical structures involved, and reviews the findings of olfactory performance in patients with neurological dysfunction. The findings are then integrated with neuropathological studies of patients with schizophrenia. Finally, as there is increasing evidence for a sex difference in patients with schizophrenia, a model is suggested to account for these differences based on neuro-developmental and latent lesion hypotheses.