Christoph U Correll,1â 3 Paolo Fusar-Poli,4â 6 Stefan Leucht,7 Anne Karow,8 Nadja Maric,9 Carmen Moreno,10 Merete Nordentoft,11 Andrea Raballo12,13 1Department of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Berlin, Germany; 2Department of Psychiatry and Molecular Medicine, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA; 3Department of Psychiatry, The Zucker Hillside Hospital, Glen Oaks, NY, USA; 4Early Psychosis: Interventions and Clinical-detection (EPIC) Lab, Department of Psychosis Studies, Institute of Psychiatry, Psychology & Neuroscience, Kingâs College London, London, UK; 5OASIS service, South London and Maudsley NHS Foundation Trust, London, UK; 6Department of Brain and Behavioural Sciences, University of Pavia, Pavia, Italy; 7Section Evidence-Based Medicine in Psychiatry and Psychotherapy, Department of Psychiatry and Psychotherapy, Technical University of Munich, School of Medicine, Munich, Germany; 8Department of Psychiatry and Psychotherapy, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; 9Faculty of Medicine, University of Belgrade and Institute of Mental Health, Belgrade, Serbia; 10Department of Child and Adolescent Psychiatry, Institute of Psychiatry and Mental Health, Hospital General Universitario Gregorio Marañón, School of Medicine, Universidad Complutense, IiSGM, CIBERSAM, Madrid, Spain; 11CORE-Copenhagen Research Centre for Mental Health, Mental Health Services in the Capital Region, Department of Clinical Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; 12Section of Psychiatry, Clinical Psychology and Rehabilitation, Department of Medicine, University of Perugia, Perugia, Italy; 13Centre for Translational, Phenomenological and Developmental Psychopathology (CTPDP), Perugia University Hospital, Perugia, ItalyCorrespondence: Christoph U CorrellDepartment of Child and Adolescent Psychiatry, Charité Universitätsmedizin, Augustenburger Platz 1, Berlin, 13353, Germany, Tel +49-30-450-566202, Fax +49-30-450-566921, Email christoph.correll@charite.dePurpose: Although first-episode psychosis (FEP) in youth, particularly early-onset schizophrenia (EOS), is managed similarly to adult-onset schizophrenia, few antipsychotics are approved for people aged 13â 18 years. We aimed to explore areas of uncertainty in EOS management and provide evidence-based recommendations to mental health specialists. We used the Delphi methodology to gain knowledge in areas lacking evidence-based strategies. This standardized methodology consists of the development of a questionnaire by content experts, which is then submitted to a broader panel of professionals (panelists) to survey their level of agreement on the topics proposed.Materials and Methods: The developed questionnaire covered patient management from diagnosis to maintenance treatment and was administered to a broader panel of specialists across Europe. Based on an analysis of responses received in this first round, the items that needed further insight were submitted to the panel for a second round and then reanalysed.Results: An initial set of 90 items was developed; in round I, consensus was reached for 83/90 items (92%), while it was reached for 7/11 (64%) of the items sent out for rerating in round II. Feedback for rounds I and II was obtained from 54/92 and 48/54 approached experts, respectively. There was broad agreement on diagnostic standards, multimodal approaches and focus on adverse events, but uncertainty in terms of pharmacological strategies (including clozapine) in case of failure and antipsychotic dosing in younger patients.Conclusion: Despite knowledge about diagnostic clues and integrated management of EOS, this study highlights the lack of standardization in treating EOS, with safety arguments having a major role in the decision-making process. Targeted clinical trials and systematic dissemination across Europe of current scientific evidence on the value of early intervention services is hoped to contribute to standardized and improved quality care for patients with early-phase psychosis and schizophrenia.Keywords: schizophrenia, Delphi, psychosis, early onset, management