Dimensional and Developmental Profiles of Psychosis in Children and Adolescents

This study aims to better understand psychosis in children and teenagers by examining its different forms and how it develops over time. Researchers will look at clinical, genetic, and brain imaging data to improve how psychotic disorders are diagnosed and treated in young people. **You may be eligible if...** - You are between 7 and 20 years old and your first psychotic symptoms began between ages 7 and 17 - You have been diagnosed with schizophrenia, schizoaffective disorder, brief psychotic disorder, or depression with psychotic features - You have been hospitalized or are receiving outpatient treatment for a psychotic episode - Parents or siblings may also participate in the genetic part of the study - You are covered by French Social Security **You may NOT be eligible if...** - You have a moderate or severe intellectual disability (IQ below 50) - Your psychosis is caused by a medical condition, medication, or drug use - You have a diagnosis of bipolar disorder - You are under legal guardianship - You have a contraindication to MRI (for the brain imaging part only) Talk to your doctor to see if this trial is right for you.