ISRCTN32309003.

Study name	A national randomised controlled trial to evaluate mentalisation based therapy for antisocial personality disorder
Methods	Design: parallel randomised controlled trial
Participants	Participants: male offenders who have a history of violent behaviour, are subject to statutory provision by the National Probation Service and have at least 6 months remaining on their licence Age: 21 years or above Unit of allocation: multicentre trial; 1:1 allocation Target sample size: 302 Inclusion criteria: participants subject to statutory provision by the National Probation Service; aged 21 or over; at least 6 months remaining of their license or community sentence; adequate level of English; evidence of a history of violent behaviour, that may include verbal assault, assaults against objects and/or assault against others; DSM‐IV‐R diagnosis of AsPD (using SCID‐II); and evidence of recent aggressive acts (using OAS‐M) Exclusion criteria: conviction for child sexual offences (including child pornography); current diagnosis for schizophrenia or bipolar disorder; neurodevelopmental disorder or significant cognitive impairment; severe substance or alcohol dependency
Interventions	Two conditions: mentalisation‐based therapy for anti‐social personality disorder (MBT‐ASPD); or probation as usual (PAU) Experimental group: MBT‐ASPD Control group: PAU Details of conditions: MBT‐ASPD is described as a programme of group and individual psychotherapy; all participants randomised to MBT‐ASPD will have an allocated psychiatrist, a therapist who will provide individual therapy and two group therapists (one of whom will be their individual therapist). The therapist will provide a monthly 1‐hour individual mentalisation‐based therapy session. Participants will also attend weekly group mentalisation‐based therapy for 75 minutes. Participants randomised to PAU remain under the supervision of their probation trust for the duration of their licence or community sentence. Duration of intervention: 2 months, after which patients will be reassessed by a member of the trial clinical team and referred for further management if required, for up to 12 months Duration of trial: 24 months (assessment at baseline, month 6 and 12 (in‐treatment), month 18 and 24 (post‐treatment) Length of follow‐up: 12 months
Outcomes	Primary outcomes of trial Aggression: frequency of aggressive acts measured using a self‐report, 5‐item version of the Overt Aggression Scale Modified Secondary outcomes of trial Global state/outcomes:assessed with Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE‐OM); EuroQoL 5 dimensions (EQ‐5D); Brief Symptom Inventory (BSI) Mental state: assessed with Psychopathic Personality Inventory‐ Revised (PPI‐R); assessed with State Trait Anger Expression Inventory 2 (STAXI‐2); Suicidal Behaviours Questionnaire–Revised (SBQ–R); Self Harm Inventory (SHI) Violent behaviour: assessed with MacArthur Community Violence Screening Instrument (MCVSI) Offending: offending behaviour Social functioning: assessed with Social Functioning Questionnaire (SFQ) Impulsivity: assessed with Barratt Impulsiveness Scale (BIS) Substance use: assessed with Alcohol Use Disorders Identification Test (AUDIT); Drug Use Disorders Identification Test (DUDIT) Service use: assessed using Secure Facilities Service Use Schedule (SFSUS); Service Engagement Scale (SES) Satisfaction with treatment: assessed with Client Satisfaction Questionnaire (CSQ) Other outcomes of trial Reflective Functioning Questionnaire‐54 (RFQ54) Movie for the Assessment of Social Cognition (MASC) Social hierarchy game Investor trustee game
Starting date	01 January 2016
Contact information	Ms Elizabeth Simes (email: MOAM@ucl.ac.uk) Address: Research Department of Clinical Educational & Health Psychology, University College London, 1‐19 Torrington Place, London, United Kingdom, WC1E 7HB
Notes	Sponsor: project funded by the National Institute for Health Research HTA (14/186/01)