ISRCTN14994755.

Study name	Low intensity psychological support for people with personality disorder: randomised controlled trial
Methods	Design: parallel randomised controlled trial
Participants	Participants: adults using secondary care mental health services in London, UKa Age: 18 years or over Unit of allocation: 1:1, stratified by referring team and gender Target sample size: 60 Inclusion criteria: clinical diagnosis of personality disorder; positive screening result using the International Personality Disorder Examination self‐administered questionnaire; competent and willing to provide written, informed consent Exclusion criteria:current clinical diagnosis of a coexisting organic or psychotic mental disorder (dementia, bipolar affective disorder (type I and II), delusional disorder, schizophrenia, schizoaffective disorder or schizotypal disorder; cognitive or language difficulties that would preclude subjects providing informed consent or compromise participation in study procedures; currently receiving psychological treatment for personality disorder
Interventions	Two conditions: psychological support for personality (PSP); or treatment‐as‐usual (TAU) Experimental group: PSP Control group: TAU Details of conditions: PSP is described as a 'flexible' intervention delivered by clinical staff who receive regular supervision and have experience in working with people with PD. Sessions last between 45‐60 minutes and are delivered on an individual basis over a three to six‐month period; the total number of sessions can be between six and ten. Telephone support is also provided. Session content includes information on personality, personality disorder, validation and acceptance, tailored psychological support aimed at promoting mentalising and distress tolerance TAU is delivered by staff working in community mental health teams. TAU comprises assessment, care planning, review, and may involve pharmacotherapy and referral to other services including access to inpatient care at times of crisis Duration of intervention: flexible (6 to 10 sessions, delivered over 3 to 6 months) Duration of trial: six months Length of follow‐up: 24 weeks after baseline
Outcomes	Primary outcomes of trial Social functioning: assessed using Work and Social Adjustment Scale (WSAS) Mental state: assessed by Warwick‐Edinburgh Mental Wellbeing Scale (WEMWBS) Suicidal thoughts: National Household Survey of Psychiatric Morbidity (NHSPM) Health‐related quality of life: EuroQol 5 dimension, 5 levels instrument (EQ‐5D‐5L) Satisfaction with care: Client Satisfaction Questionnaire (CSQ) Resource use and costs; modified version of the Adult Service Use Schedule (ASUS) Change in global mental health; Clinical Global Impression (CGI) scale Secondary outcomes of trial Participants will be asked to state how confident they are in their ability to “get yourself through difficult times and situations" (quote; p 7, column 2) on a five‐point Likert scale (ranging from totally confident to totally unconfident) Other outcomes of trial Following completion of the six‐month follow‐up interview, up to 20 participants will be invited to take part in a separate interview about their experience of taking part in the study and any ways improve the design of a future definitive trial.
Starting date	13 July 2017
Contact information	Ms Amy Claringbold (email a.claringbold@imperial.ac.uk) Address: Personality Disorder Research Unit, Centre for Psychiatry, Imperial College London, London, UK Tel: +44 20 8383 4134 Sponsor: Central and North West London NHS Foundation Trust Funder: National Institute for Health Research
Notes	aRecruitment from community mental health teams, home treatment teams, and other community‐based mental health services