Mentalization Based Treatment (MBT) in Help Seeking Youths With a Clinical High-Risk Condition for Psychosis (CHR-P)

The primary objective of this study is to evaluate the efficacy of Mentalization-Based Treatment (MBT) combined with Need-Based Clinical Interventions (NBCI) compared to NBCI alone, on CHR-P diagnostic statuses and symptom expression (Hypothesis 1). Specifically, the investigator will assess diagnostic outcomes using a 3-level variable: transition to psychosis, CHR-P status quo, and remission out of CHR-P, as well as CHR-P symptom expression. The investigator hypothesize that: (1a) the experimental treatment (MBT + NBCI) will have a significant effect on diagnostic status (i.e. transition to psychosis) at the end of treatment and follow-up; (1b) the experimental treatment (MBT + NBCI) will significantly reduce the severity of psychotic symptoms at the end of treatment and follow-up.

Inclusion Criteria: * Patients aged 14-30 years with a CHR-P condition, as defined by the SIPS criteria * Patients who provide informed consent Exclusion Criteria: * Patients with a prior diagnosis of a psychotic disorder * Intellectual disability (IQ \< 70). * Patients whose psychotic symptoms are primarily induced by substance misuse. * Patients with significant language barriers * Parents/legal authority who do not provide informed consent (only minors) * Adult patient under guardianship Note: Comorbidities with other psychiatric disorders (e.g., Autism Spectrum Disorder, Personality Disorders) will not constitute an exclusion criterion.