Historically, there has been a lot of skepticism about whether antisocial personality disorder (ASPD) can be treated psychologically. The evidence for psychological interventions to treat aggression in ASPD produced mixed results. Persistent problems like aggression, recklessness, irritability, dishonesty, and lack of remorse characterize ASPD. ASPD occurs in about 2.10% to 4.16% of the population, and in people convicted of violent offences, it can reach up to 50%. ASPD has been linked to childhood antisocial behaviours, genetic predispositions, and growing up in an abusive environment. Childhood maltreatment can impair the development of mentalizing, which is critical to interpreting social cues, regulating emotions, and the capacity to empathize and consider others’ mental states. Mentalizaing refers to the capacity to understand one's own and others' behaviors in terms of mental states (i.e., that behaviors are the result of feelings, thoughts, desires, intentions). People with ASPD demonstrate impaired mentalizing. Mentalization-based therapy (MBT) addresses mentalizing vulnerabilities, often related to trauma, to improve individuals’ capacity to empathize and regulate emotions. In this large randomized controlled trial, Fonagy and colleagues evaluated the effectiveness of MBT in reducing aggressive behaviours from baseline to 12 months post-randomization. Adult male participants with ASPD (N = 314) who were convicted of an offence were randomly assigned to MBT or probation as usual for 12 months. MBT was delivered in weekly group therapy plus a monthly individual session. Those in the probation-as-usual condition met regularly with a probation manager and had access to anger management programs and domestic violence courses. At 12 months after random allocation, mean scores on an aggression measure were significantly higher in the probation as usual group (mean score 186 [SD 153]) than in the MBT group (90 [126]), with an adjusted mean difference between groups of –73.5 (95% CI –113.7 to –33.2); p < 0.0001, indicating a medium to large effect size of 0.74. There was also evidence that MBT reduced recidivism, resulted in fewer individuals meeting diagnostic criteria for ASPD, and improved negotiation skills in intimate partner violence. MBT also resulted in improved mentalizing capacity, and a mediation analysis showed that this improvement in mentalizing capacity explained the treatment’s impact on reduced aggression.
This is an impressive and large study of an effective treatment for a population with antisocial personality disorder (ASPD), often thought to be untreatable by psychological means. Mentalization-based treatment (MBT) may increase individuals’ ability to understand and reflect on their own and others’ mental states, i.e., to mentalize. This is thought to improve social cognition and empathy, which in turn may reduce verbal aggression and aggressive behaviours.
Fonagy, P., Simes, E., Yirmiya, K., Wason, J., Barrett, B., Frater, A., … Bateman, A. (2025). Mentalisation-based treatment for antisocial personality disorder in males convicted of an offence on community probation in England and Wales (Mentalization for Offending Adult Males, MOAM): A multicentre, assessor-blinded, randomised controlled trial. The Lancet Psychiatry, 12(3), 208–219. https://doi.org/10.1016/S2215-0366(24)00445-0