Mentalization for Offending Adult Males (MOAM)

'Personality disorder' refers to the enduring problems that some people have in managing their feelings and relating to other people. Antisocial personality disorder (ASPD) is a particular type of personality disorder characterised by a disregard for, and violation, of the rights of others. Features include aggression, impulsive behaviour and repeatedly doing things that are grounds for arrest. Consequences commonly include violent criminal behaviour causing direct emotional and physical injury to victims. ASPD is particularly common in the criminal justice system: while it affects 0.6% of the UK general population, up to 63% of offenders are affected. ASPD poses a huge health burden for individuals, communities and wider society. People with ASPD are more likely to suffer from mental and physical health problems associated with their antisocial lifestyle and are more likely to die at a younger age. Despite its harmful outcomes, there is no solid evidence for any successful treatment for ASPD. Whilst a range of psychological interventions have been shown to be effective in the management of other personality disorders, most psychological treatments are not specifically designed for people with ASPD. We aim to test a treatment that has been specifically adapted for ASPD, from a model known as Mentalization-Based Treatment (MBT). MBT is a psychological treatment that focuses on improving understanding of our own and others' mental states, an ability that forms the basis for the everyday judgements we all make about the meaning of other peoples' behaviour and how to respond to it. MBT has been shown to be effective in patients with another type of personality disorder called borderline personality disorder (BPD). It has also been shown to be effective in patients with both BPD and ASPD, and has now been specifically adapted for ASPD. Despite promising preliminary work, we do not yet know whether MBT is effective for ASPD. Our study will look at whether MBT can reduce aggressive behaviour of offenders with ASPD, and whether it does so more effectively and cost-effectively than the usual services offered to offenders on probation. We will conduct this research across 13 sites nationwide, each overseen by a research team with expertise in personality disorders, offenders' mental health, and the development and evaluation of psychological treatments. To ensure that we achieve the fairest and least biased assessment of the potential effects of MBT, offenders who are suitable for our study will be allocated at random to either probation services as usual (PAU) or MBT on top of PAU, which they will receive for 12 months. We will compare outcomes of the two groups by looking at the frequency of aggressive acts. We are also interested in other possible differences between the groups in terms of their health, quality of life, and reoffending rates. We will look at these outcomes during the 12 months that they receive treatment (either MBT or PAU), and for 12 months after they have completed treatment. Outcomes will be assessed through interviews conducted by ex-offenders specifically trained for this study. We will analyse the data to determine whether MBT improves outcomes and if it represents an economically viable option for national provision for this group. This is the first ever large-scale trial of treatment for offenders with ASPD in the community and will provide key evidence to inform treatment decisions in this group.