This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: The primary objective is to investigate the effects of atypical antipsychotic medications in adolescents with psychosis. We will review various comparisons of atypical antipsychotic medications with placebo or a typical antipsychotic medication or another atypical antipsychotic medication or same atypical antipsychotic medications but at a lower dose in separate analyses.