Developing and Testing a Group Therapy Programme to Treat Aggressive Script Rehearsal in an Incarcerated Offender Population

Aggressive script rehearsal is associated with violent offending. However, no treatment focusing exclusively on aggressive script rehearsal has been developed or tested. This thesis commences with a review of the literature concerning aggressive script rehearsal in offender populations and examines possible treatment approaches. A novel seven session group-based aggressive script rehearsal treatment programme is then created and evaluated. The aim of this evaluation was to explore whether aggressive scripts could be targeted through group treatment. The efficacy of this aggressive scripts group was compared to an emotion regulation group-based treatment in a non-randomised trial. It was hypothesised that both group treatments would offer efficacy in reducing aggressive scripts and hostility, as well as improving emotion regulation, psychological flexibility, and general psychological wellbeing. Participants were 48 male prisoners (20 in the control and 28 in the experimental group). Participants completed psychometric testing pre-and post-treatment, and then at two follow-up points after the treatments were completed. Psychometric evaluation included repeat administration of an adapted version of the Schedule of Imagined Violence (adapted to assess for aggression as well as aggressive scripts), the Difficulties in Emotion Regulation Scale, the Acceptance and Action Questionnaire-II, and the Brief Symptom Inventory. A brief measure of aggressive script rehearsal was also administered during sessions two through seven. Treatment efficacy was explored through several Mixed-Methods ANOVAs and Hierarchical Linear Modelling. Results indicated statistically significant improvements in emotion regulation, psychological flexibility, hostility, and general psychological wellbeing, over time, in both groups. The hypothesis that aggressive script rehearsal would significantly decrease as a result of group participation, was not supported. These findings suggest that groups targeting both aggressive scripts and emotion dysregulation can promote change in an array of psychological domains that are linked to aggressive script rehearsal. However, it appears that these groups were not sufficient to produce a significant decrease in aggressive script rehearsal directly.