Rep36 Understanding Personality Disorder

Dr Maggie Hilton
is a Consultant Forensic Clinical Psychologist who worked for 12 years as the Head of
Psychology at the Pathfinder Forensic Psychiatry Service. She was then employed in the Henderson
Outreach Service, setting up and developing an innovative service for people with severe personality
disorders prior to and following their treatment at Henderson Hospital. She currently works in a free-
lance capacity.
Dr Caroline Logan
is a Consultant Specialist Clinical Psychologist working in Mersey Care NHS Trust
and based at Ashworth Hospital in Liverpool. She specialises in risk and personality disorder
assessment and training following five years of post-doctoral research on violence and sexual violence
risk assessment in incarcerated men and women funded by the National R&D Programme on Forensic
Mental Health. She is a Board Member of the Risk Management Authority in Scotland.
Mr John Shine
works as Principal Psychologist for the John Howard Centre and has worked as a
forensic psychologist in prison and forensic mental health for over 20 years. 
Acknowledgements
The authors would like to acknowledge the contributions made to this report by the following colleagues:
Dr Louise Horne (Ashworth Hospital), Professor Peter Kinderman (University of Liverpool), Professor
David Pilgrim (University of Liverpool) and Mrs Moira Potier (Mersey Care NHS Trust).

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1
Personality disorder can be defined as variations or exaggerations of normal personality attributes.
Personality disorders are often associated with antisocial behaviour, although the majority of people
with a personality disorder do not display antisocial behaviour. Many people with mental health problems
also have significant problems of personality, which can reduce the effectiveness of their treatments.
Research suggests that about ten per cent of people have problems that would meet the diagnostic
criteria for personality disorder. Estimates are much higher among psychiatric patients, although they
vary considerably: some studies have suggested prevalence rates among psychiatric outpatients that are
in excess of 80 per cent. Between 50 per cent and 78 per cent of adult prisoners are believed to meet
criteria for one or more personality disorder diagnoses, and even higher prevalence estimates have
been reported among young offenders.
There is no single known cause of personality disorder: a combination of biological, social and
psychological factors are implicated. Memory systems relating to the self and others are thought to be
central to personality disorder, and the development of these systems depends on learning experiences
in early relationships. Biological factors also influence personality development and may limit the
extent to which traits of personality disorder can change. Many individuals are resilient to the
biopsychosocial stress associated with the development of personality disorder; they would appear to
possess resilient temperaments and/or have experienced adaptive socially environments and/or sought
alternative positive attachments.
The first step in treating personality disorder is personality assessment, using carefully selected and
structured instruments with established and well-documented psychometric properties. Self-report
instruments and semi-structured interviews are recommended to establish goals, maintain focus in the
therapeutic process, contribute to the choice and sensitivity of intervention strategies, and to monitor
change over time.
Although there are few well controlled studies, research findings suggest that people with
personality disorder can be treated successfully using psychological therapies. There is no clear
evidence of the superiority of one type of treatment approach over another or for a particular method
of service delivery (inpatient, outpatient, day programme). However, treatment benefits appear
particularly evident when treatment is intensive, long-term, theoretically coherent, well structured and
well integrated with other services, and where follow-up to residential care is provided. The efforts
made in engaging patients and keeping them engaged in treatment, and the quality of the therapeutic
alliance achieved, are crucial factors in determining treatment outcome. There is a need for further
research with carefully defined populations, clearly defined treatment goals, and long follow-up periods
incorporating cost benefit analyses.
Little is known about the relationship between different types of personality disorder and offending
behaviour. Treatment in forensic populations should take account of the risk level of offenders, the
factors associated with their offending, and the types of interventions to which they are likely to be
responsive. Interventions with forensic populations have favoured social learning and cognitive-
behavioural models. Democratic therapeutic communities have shown evidence of reducing symptoms
of personality disorder in disturbed populations. Preparation, support and after-care for offenders are
essential requirements in maximising the impact of rehabilitation programmes. Further research is
needed on how different types of personality disordered offenders respond to current treatments and
the conditions that are needed to sustain improvements following completion of treatment.