 The study is a prospective 2 year multimodal follow-up study of initially antipsychotic-naïve first-episode psychotic patients involving a standardized intervention with monotherapy with aripiprazole during the first 6 weeks. Patients and matched healthy controls will be examined after 6 weeks, 6 months and 2 years. They will be examined with MR-scannings, neurocognitive tests, EEG, and PET-scannings. 