Five collaborating sites in France will study the broad spectrum of schizophrenia in children and adolescents. Patients will be studied with diagnostic interviews, developmental histories, dimensional clinical ratings, comprehensive cognitive assessments, neuroimaging and DNA (copy number variant) analyses (in families and patients who agree), and follow-up of course of illness, cognitive status and treatment response to specific antipsychotic drugs. The goal of the study is to test a prior hypothesis about clinical subgroups in this population and to test whether these subgroups predict antipsychotic medication response.

This study relates to the organization of a collection of clinical, biological / genetic and radiological (MRI) data from people with a psychotic episode and from their families. These data will be analyzed to clarify whether there is a different response to antipsychotic treatment based on developmental and clinical expression.To answer the question asked in the research, it is planned to include people with at least one psychotic episode,The target population will be a prospective cohort of patients admitted to a hospital or psychiatric clinic for the treatment of psychotic symptoms.Comprehensive medical evaluation will be carried out according to the clinical features and medical history of each patient, to identify medical causes of psychosis. Comprehensive neuropsychological and speech / language evaluation will be completed. A child psychiatrist-diagnostician will complete the Lifetime Dimensions of Psychosis Scale - Child and Adolescent version at baseline. When the patient and parents agree, structural and functional MRI examinations will also be completed, and blood will be drawn for DNA extraction and analysis. Selected assessments (including evaluation of treatment response to specific antipsychotic drugs) will be performed at follow-up visits after 1, 3 and 5 years.

Inclusion Criteria for the Patient:

1. Children and young adults ages 7-20 years with age of onset of psychotic disorder between 7-17 years.
2. Hospitalized or seen for out-patient treatment for a psychotic episode, acute or chronic.
3. DSM-V diagnosis of schizophrenia, schizoaffective disorder, schizophreniform disorder, brief psychotic disorder, psychotic disorder not otherwise specified, or major depressive episode with psychotic features.
4. Written informed consent signed by the parents or the individual(s) with legal parental authority, and by the minor patient if his/her condition permits.
5. Written informed consent signed by the patient if he/she is a major, after clinical stabilization (not delusional).
6. Has health insurance coverage from Social Security (France) (not AME coverage).

Inclusion Criteria for parents or siblings wishing to participate in the genetic part of the study :

1. Parents : no specific criteria.
2. Siblings : siblings are eligible to participate if there are at least two first-degree relatives with psychotic disorders (including the patient) in the family.
3. Written informed consent for the genetic part of the study signed by any participating parents and siblings.
4. Has health insurance coverage from Social Security (France) (not AME coverage).

Exclusion Criteria:

1. Moderate or severe intellectual deficiency (IQ < 50).
2. Psychoses judged to be secondary to medical illness, medication effects or drugs of abuse.
3. Diagnosis of bipolar disorder.
4. Patients who are under legal guardianship.
5. For the neuroimaging part of the study only : any contraindications to Magnetic Resonance Imaging.