Abstract:Developmental clinical research in recent years has highlighted the value treating psychotic disorders at the earliest stage to reduce long-term morbidity. It is now suggested that treatment during the clinical high risk states (CHR), preceding by 1 to 4 years the onset of psychotic disorders, may delay or prevent the onset of psychosis, and contribute to a more positive prognosis. In this article, we wish to provide a rationale and clinical illustration of mentalization-based treatment (MBT) as an indicated preventive treatment for CHR. We will first review the notion of high-risk for psychosis, providing a trans-theoretical developmental framework for conceptualizing the clinical progression from sub-clinical towards clinical psychotic states. Second, we address the commonalities and differences between the constructs of mentalization and metacognition, and discuss their relevance in preventive psychotherapeutic treatment for CHR. Thirdly, we provide a clinical illustration of MBT to emerging psychosis. Finally, we conclude by discussing the specific contributions of MBT approach in youths at CHR, and the necessary research for evaluating its relevance in the context of risk for developing psychosis.In the following, we consider mentalization-based treatment (MBT) as an indicated preventive treatment for individuals at clinical high-risk (CHR) for psychosis. Mentalization (thinking about thinking; (Fonagy 1991)) is a concept used both clinically and empirically to characterize a set of social cognitive processes that convey an understanding of human behavior as motivated by intentional mental states. We will first briefly review the developmental clinical milestones of emerging psychosis. The second section will specifically discuss the relevance of processes such as mentalization or metacognition during the premorbid and CHR phases of emerging psychosis. The last section will offer a clinical case illustration of mentalization-based treatment conducted with an adolescent female at CHR for psychosis. We conclude by highlighting how mentalization-based treatment may protect at-risk individuals from converting to clinical psychotic states.