Of several scales developed in our laboratory for identifying psychosis-prone young adults, the most promising appears to be the Perceptual Aberration-Magical Ideation Scale. High-scoring subjects (2 SD > the mean) report many psychoticlike and isolated psychotic symptoms. Subjects were seen for a followup interview 25 months after the initial identification and interview. Three of 162 high-scoring perceptual aberration-magical ideation subjects reported having received their first clinical attention for psychosis during the followup period. Additional measures are being used in attempts to eliminate the false positives as well as to distinguish persons prone to schizophrenia from those prone to affective disorder with psychosis.