Title: Mentalization for Offending Adult Males (MOAM)
Funder: Department of Health and Social Care

Abstract: Background: Violent crime is associated with a range of negative impacts on health and wider society. Antisocial personality disorder (ASPD), a key contributor to violent criminal behaviour, is significantly overrepresented among offenders; it carries high rates of comorbidity and mortality for individuals, and high risk of harm to the public. NICE guidelines and Cochrane reviews highlight a lack of evidence for effective interventions for ASPD and urgently recommend research to determine effective and cost-effective interventions for this condition. Our study responds to the gap in the knowledge base by testing the effectiveness of an existing evidence-based treatment in a new target population and context: offenders with ASPD under community supervision. Research Question: Is Probation As Usual (PAU) supplemented with Mentalization-Based Treatment (MBT) more effective and cost-effective than PAU only for reducing aggressive antisocial behaviour and improving wider health outcomes in offenders under community supervision who meet DSM-5 diagnostic criteria for ASPD? Design: A multi-site, two-arm, three-phase randomized controlled trial lasting a total of 60 months, with participants randomly allocated in a 1:1 ratio to receive either PAU only or MBT plus PAU. Setting: National Probation Service (NPS) and partner NHS Trusts at 13 sites across England and Wales. Target population: Male offenders over 21 years subject to statutory supervision by the NPS with at least 6 months remaining of their licence or community sentence, who fulfil DSM-5 diagnostic criteria for ASPD. Sample Size: Our recruitment target is 302 participants; each site is expected to recruit 1 eligible consenting participant per month. This allows for 37% attrition, to end up with 95 participants per arm, yielding 90% power. Health Technology: MBT is a transdiagnostic manualised psychosocial intervention aimed at improving the capacity to use mental state concepts to interpret and organise behaviour. Participants randomised to MBT will receive 12 months of weekly 75-minute group sessions and monthly 60-minute individual sessions; their aim is to stabilise emotional expression and achieve control over aggressive behaviour through increased awareness of mental states that trigger aggressive impulses. MBT will be delivered by NHS and Probation staff and funded by NHS England as part of the National Offender Personality Disorder Pathways Strategy. Outcomes: These will be collected over the 12 months of intervention and the 12-month follow-up period. The primary outcome will be frequency of aggressive antisocial behaviour measured by the Overt Aggression Scale–Modified, collected every 3 months. Secondary outcomes include mental health, quality of life, and offending behaviour, collected every 6 months. Outcome assessments will be conducted by ex-offenders with experience of service user involvement in research. The primary outcome will be analysed using a hierarchical mixed-effects linear regression. Secondary outcomes will be analysed using mixed-effects linear regression, mixed-effects logistic regression models and mixed-effects Poisson models as appropriate. Economic evaluation will be conducted from both a NHS/PSS perspective and a wider societal perspective. Cost-effectiveness analysis will combine data on costs with aggressive antisocial behaviour; cost-utility analysis will combine data on costs with Quality Adjusted Life Years.

Lay abstract: ‘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.

Research activity codes: 6.6 PSYCHOLOGICAL AND BEHAVIOURAL
Health categories: MENTAL HEALTH