subclinical symptoms may emerge; they include withdrawal or isolation, irritability, suspiciousness, unusual thoughts, perceptual distortions, and disorganization (1). Onset of overt schizophrenia (delusions and hallucinations) may be sudden (over days or weeks) or slow and insidious (over years). But, even in an advanced prodromal phase, only a fraction (< 40%) tend to convert to full schizophrenia.