This study was a component of a large program of research aiming to address the issues of identifying young people at high risk of psychosis, characterising the transition from high risk to acute psychosis and developing appropriate preventive interventions for this population. Participants were almost 40 young people at a ultra-high risk of developing a psychotic disorder, attending the Personal Assessment and Crisis Evaluation (PACE) Clinic in Melbourne, Australia. Participants were evaluated at baseline in 2000 and were assessed monthly for 12 months and again at 24 months to determine the onset of acute psychosis. Participants have been followed up for psychosis incidence through the PACE 400 and UHR 1000+ cohort studies.