Rep36 Understanding Personality Disorder

1.2.3 Prevalence of personality disorders in
mentally disordered offenders
In a study of mentally disordered offenders in
English and Scottish high secure hospital care,
antisocial, narcissistic and borderline personality
disorders were the most common personality
disorder diagnoses; almost two thirds of a sample
of 175 male patients in high secure forensic
psychiatric care met criteria for a definite
diagnosis of at least one personality disorder
(Blackburn, Logan, Donnelly & Renwick, 2003).
Evidence of significant psychopathic traits (as
defined by elevated scores on the Psychopathy
Checklist-Revised; Hare, 1991, 2003) was
detected in almost one third of the same sample. 
With respect to comorbidity in male mentally
disordered offenders, research suggests that all
personality disorders, with the exception of
narcissistic, dependent and obsessive-compulsive
disorders, are associated with an increased
likelihood of at least one lifetime Axis I disorder
diagnosis (Blackburn 
et al
., 2003). For example,
a diagnosis of borderline personality disorder
was associated with a significant likelihood of co-
occurring diagnoses of depression, obsessive-
compulsive disorder, post-traumatic stress
disorder, and both alcohol and drug abuse. In
contrast, avoidant personality disorder was
associated with an increased likelihood of
anxiety, bipolar disorders and post-traumatic
stress disorders. 
In a study of women in high secure prison
and forensic psychiatric care using structured
assessments of personality disorder (namely the
Structured Clinical Interview for DSM-IV Axis II

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Personality Disorder Diagnoses or SCID-II; First
et al
., 1997), the most commonly occurring
personality disorder diagnoses were antisocial
and borderline personality disorders (Logan,
2002; Logan, 2003). In a sample of hospitalised
women, the prevalence of borderline personality
disorder just exceeded that of antisocial
personality disorder. Over three quarters of the
sample of hospitalised and imprisoned women
received at least one definite personality disorder
diagnosis, and comorbidity was common. For
example, a diagnosis of any substance dependence
disorder was almost six times more likely to be
associated with a diagnosis of antisocial
personality disorder and three times more likely
to be associated with a diagnosis of borderline
disorder. Also, a high level of comorbidity was
detected between diagnoses of borderline
personality disorder and psychotic disorders.
Characteristics consistent with the clinical
description of psychopathy were detected in 15
per cent of the women assessed in this study.