Because of the complex range of factors to be considered in pscyhosis -genetic, neurologic, biologic, environmental, family, culture - this issue of Child and Adolescent Psychiatric Clinics presents aspects that have the greatest relevance and impact in diagnosing and treating child and adolescent patients. Among some of the topics covered: Schizophrenia, Affective disorders and Psychosis, Comorbid diseases, Neurocognition, Genetics, Neuroimaging findings, and Treatment approaches of Psychopharmacology, Psychotherapy, and Community Rehabilitation. Jean Frazier, an expert in child and adolescent neuropsychiatry and in child psychopharmacology, leads this issue along with Yael Dvir, whose research and clinical interests include childhood psychosis and the associations between childhood psychosis and Autistic Spectrum Disorders.