Schizophrenics have difficulty identifying odors, and problems with the sense of smell seem to be linked with the disease. Among high-risk patients, a recent study found, problems with olfaction predicted who was most likely to develop the disorder. The findings suggest that testing a patient’s sense of smell could become a useful method to predict who is most likely to develop the psychiatric disorder.
Warrick Brewer, a psychiatrist from the University of Melbourne in Australia, and colleagues compared the olfactory abilities of a group of 81 high-risk patients against those of 31 volunteers in a control group. The at-risk group were recruited from a university sponsored clinic that monitors teens who appear to be developing a serious mental illness, yet have not yet had any psychotic episodes. After 18 months, 22 of the high-risk patients suffered psychotic episodes and 12 were found to be schizophrenic.
Of the participants involved in the study, only those who later became schizophrenic scored significantly worse in initial olfactory testing. The findings, published in this month's American Journal of Psychiatry, may help develop a diagnostic tool to predict who is most at risk for the disorder. Brain imaging, clinical symptoms and genetics have failed to find a reliable predictor.