Mentalisation-Based Treatment (MBT) in youth at Clinical High-Risk for Psychosis (CHR-P): study protocol for a randomised controlled trial (MBT-Psychosis).

backgroundPsychoses are among the most severe disorders in children and adolescents, representing the second leading cause of years lost due to disability worldwide. Evidence suggests that early intervention in psychosis may improve outcomes, and there is increasing consensus among clinicians to initiate treatment as soon as sustained positive psychotic symptoms emerge. Within this early intervention framework, intervening during the clinical high risk for psychosis (CHR-P) phase may mitigate, delay or even prevent the onset of a full psychotic disorder.Recent psychological, clinical and neuroscientific studies underscore that socioemotional difficulties are critical determinants of clinical and functional outcomes in CHR-P individuals. Mentalising, or the ability to think about mental states, is refined during adolescence and has proven to be critical to adult social adaptation, notably playing a crucial role in maintaining good mental health and role functioning. Mentalisation-based treatment (MBT), a highly effective psychotherapeutic model for addressing chronic socioemotional difficulties, has been recently adapted for youth at CHR-P. METHODS AND ANALYSIS: This trial will include 212 patients aged 14-30 years with a CHR-P state, as defined by the Structured Interview for Psychosis-Risk Syndromes criteria, randomly assigned to either the intervention group with MBT and need-based clinical intervention (NBCI) or the control group with NBCI alone. The MBT intervention consists of 24 weekly individual psychotherapy sessions, supplemented by monthly mentalisation-based family therapy sessions. Control intervention will consist of routine care based on NBCI. We will evaluate participants at baseline, 12 weeks, 24 weeks and 48 weeks. Impact of intervention on psychotic transition rates and symptom severity, as well as functioning, will be tested. Several potential mediators/moderators, including childhood trauma and schizotypal traits, will also be examined. ETHICS AND DISSEMINATION: This trial was approved by the Swiss National Fund and the cantonal Ethics committee (CER-VD). A lay summary of the results will be published online for the general public and detailed results will be reported in future study publications, and presented during national and international conferences. TRIAL REGISTRATION NUMBER: NCT07093671.