Assessing mentalization in psychotherapy: first validation of the Mentalization Imbalances Scale

The aim of this study was to provide data on the preliminary validation of a clinician-report multidimensional assessment measure of mentalization (Mentalization Imbalances Scale, MIS). A random national sample of psychotherapists (N=190) completed the MIS to identify mentalization imbalances, and the Personality Disorder Checklist to assess the personality disorders (PDs) of randomly selected patients currently in their care. Factor analysis confirmed the presence of six factors that represented different imbalances of mentalization: cognitive, affective, automatic, external, imbalance toward others, and imbalance toward self. We found several significant relationships between patients’ mentalization imbalances and personality pathology. Paranoid, schizoid, and schizotypal PDs were predicted by an imbalance toward self, an imbalance the patients shared with histrionic, avoidant, and obsessive compulsive PDs, whereas dependent, borderline, and histrionic PDs were related to an imbalance toward others. Cognitive imbalance was related to schizoid, narcissistic, and obsessive compulsive PDs, whereas affective imbalance predicted antisocial, borderline, narcissistic and histrionic PDs. Automatic imbalance was related to schizotypal, antisocial, and borderline PDs. MIS represents a reliable and valid measure that can help clinicians at understanding patients’ specific difficulties of mentalization.