<qa>  What is the purpose of this randomized controlled trial?The purpose of this randomized controlled trial is to develop a cognitive behavioral therapy CBT for persons with at risk mental states in the early initial prodromal state and to evaluate CBT in comparison to supportive counselling SC.It is hypothesized that CBT is more effective than SC on transition to subthreshold psychosis, psychosis and schizophrenia as well as on prodromal symptoms and social adjustment. 