A randomised controlled trial (RCT) to assess the incremental costs and clinical benefits of cognitive analytic therapy (CAT) to standard care within community mental health teams in the treatment of severe personality disorder

INTERVENTION: 1. 24 sessions of cognitive‐analytical therapy (CAT) 2. Standard care CONDITION: Mental and behavioural disorders: Other mental disorder ; Mental and Behavioural Disorders ; Other mental disorder PRIMARY OUTCOME: Beck Depression Inventory, Structured Clinical Interview for DSM‐IV, MCMI‐III, Client Service Receipt Interview. SECONDARY OUTCOME: Not provided at time of registration INCLUSION CRITERIA: 48 'hard to treat' mental health service users with complex mental health problems who have been in active contact with the participating trusts for at least one year and whose major presenting problems have not been successfully treated. INCLUSION CRITERIA: 1. A diagnosis of Cluster B Personality Disorder (Diagnostic and Statistical Manual of Mental Disorders, fourth edition [DSM IV], Axis II ‐ as per Million Clinical Multiaxial Inventory III [MCMI III]) 2. A Beck Depression Index score above 25 3. One year (or longer) history of unsuccessful treatment (assessed by case note review by the responsible medical officers [RMOs]); or at least two hospital admissions in the past 5 years following parasuicide. 4. Still on active caseload of Community Mental Health Team (CMHT) (Care Programme Approach [CPA] level 1 or higher).