Cognitive behaviour therapy for violent men with antisocial personality disorder in the community: an exploratory randomized controlled trial K. M. Davidson 1 *, P. Tyrer 2 , P. Tata 3 , D. Cooke 4 , A. Gumley 1 , I. Ford 5 , A. Walker 5 , V. Bezlyak 5 , H. Seivewright 2 , H. Robertson 1 and M. J. Crawford 2 1 Faculty of Medicine, University of Glasgow, Gartnavel Royal Hospital, Glasgow, UK 2 Department of Psychological Medicine, Imperial College London, London, UK 3 Adult Psychology Services, Central North West London NHS Foundation Trust, Psychology Department, London, UK 4 Department of Psychology, Glasgow Caledonian University, Glasgow, UK 5 Robertson Centre for Biostatistics, Boyd Orr Building, University of Glasgow, UK Background. Little information exists on treatment effectiveness in antisocial personality disorder (ASPD). We investigated the feasibility and effectiveness of carrying out a randomized controlled trial of cognitive behaviour therapy (CBT) in men with ASPD who were aggressive. Method. This was an exploratory two-centre, randomized controlled trial in a community setting. Fifty-two adult men with a diagnosis of ASPD, with acts of aggression in the 6 months prior to the study, were randomized to either treatment as usual (TAU) plus CBT, or usual treatment alone. Change over 12 months of follow-up was assessed in the occurrence of any act of aggression and also in terms of alcohol misuse, mental state, beliefs and social functioning. Results. The follow-up rate was 79 %. At 12 months, both groups reported a decrease in the occurrence of any acts of verbal or physical aggression. Trends in the data, in favour of CBT, were noted for problematic drinking, social functioning and beliefs about others. Conclusions. CBT did not improve outcomes more than usual treatment for men with ASPD who are aggressive and living in the community in this exploratory study. However, the data suggest that a larger study is required to fully assess the effectiveness of CBT in reducing aggression, alcohol misuse and improving social functioning and view of others. It is feasible to carry out a rigorous randomized controlled trial in this group. Received 22 February 2008 ; Revised 12 June 2008 ; Accepted 20 June 2008 ; First published online 30 July 2008 Key words : Antisocial, CBT, personality disorder, trial. Introduction Personality disorder is the most prevalent mental dis- order among people convicted of homicide in England and Wales (Shaw et al. 1999 b). Antisocial personality disorder (ASPD) is the form of personality disorder most frequently associated with violence. Despite a community prevalence of only 10/1000 men and ap- proximately 2/1000 women (Coid et al. 2006 a), it has been estimated that a quarter of all violent incidents in Britain are committed by people with ASPD (Coid et al. 2006 b). Violent and other criminal offences committed by people with ASPD lead to high rates of contact with criminal justice services ; over half of all male prisoners in Europe and North America have ASPD (Moran, 1999). Costs associated with crime, to- gether with social work and health costs, mean that the financial burden associated with antisocial behaviour is considerable (Scott et al. 2001). Despite this, there have been few attempts to develop and evaluate in- terventions to treat ASPD. Psychological treatments have been shown to lead to behavioural change among people with other types of personality disorder (Duggan et al. 2007). Two ran- domized controlled trials in drug-abusing patients with ASPD have found no superior effect for more, compared with less, intensive interventions in drug abusers in the community (Brooner et al. 1998) and, in cocaine-dependent in-patients, those with ASPD * Address for correspondence : Professor K. M. Davidson, Faculty of Medicine, University of Glasgow, Gartnavel Royal Hospital, Great Western Road, Glasgow G12 0XH, UK. (Email : k.davidson@clinmed.gla.ac.uk) Psychological Medicine (2009), 39, 569–577. f Cambridge University Press 2008 doi:10.1017/S0033291708004066 Printed in the United Kingdom ORIGINAL ARTICLE