Impairment of olfactory identification ability in individuals at ultra-high risk for psychosis who later develop schizophrenia.
OBJECTIVE
Previous investigation has revealed stable olfactory identification deficits in neuroleptic-naive patients experiencing a first episode of psychosis, but it is unknown if these deficits predate illness onset.


METHODS
The olfactory identification ability of 81 patients at ultra-high risk for psychosis was examined in relation to that of 31 healthy comparison subjects. Twenty-two of the ultra-high-risk patients (27.2%) later became psychotic, and 12 of these were diagnosed with a schizophrenia spectrum disorder.


RESULTS
There was a significant impairment in olfactory identification ability in the ultra-high-risk group that later developed a schizophrenia spectrum disorder but not in any other group.


CONCLUSIONS
These findings suggest that impairment of olfactory identification is a premorbid marker of transition to schizophrenia, but it is not predictive of psychotic illness more generally.
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D000857:Olfaction Disorders / Q000523:psychology*; D011618:Psychotic Disorders / Q000503:physiopathology / Q000523:psychology*; D018570:Risk Assessment; D012307:Risk Factors; D012559:Schizophrenia / Q000150:complications* / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012903:Smell