An evaluation of an ‘Introduction to mentalization-based therapy’ intervention provided to men screened into the Wales offender personality disorder pathway

Mentalization-based therapy (MBT) shows promise as an intervention model for individuals with antisocial personality-related difficulties. This study evaluated a brief Introduction to MBT (MBTi) intervention for men screened into the offender personality disorder pathway in Wales presenting with antisocial personality traits. Eighteen men completed the intervention on an individual basis. Thirteen started treatment but did not complete. Change was analysed by comparing numerous psychometric measures pre- and post-treatment. Analysis was completed in two parts, firstly looking at group-level change, and then by looking at change for each individual treatment completer. As a group, completers demonstrated significant improvements on measures of mentalisation, emotion regulation, and overall psychological distress. No change was observed on measures of hope, social functioning and wellbeing. At the individual level, there was variability in treatment outcomes across both measures and participants, with reliable and clinically meaningful change observed in some cases. The most common observation, however, was ‘no change’. MBTi may hold some promise in relation to fostering change on some measures amongst high-risk individuals with complex needs.