Impairment of Olfactory Identification Ability in Individuals at Ultra-High Risk for Psychosis Who Later Develop Schizophrenia.

Examines olfactory identification ability in ultra-high-risk subjects in relation to healthy comparison subjects. Comparison of ultra-high-risk individuals who became psychotic with those who did not develop psychosis; Use of psychiatric rating scale; Evidence that improvement in olfaction ability occurs through early childhood into mid-adolescence in normal populations.