The British Journal of Psychiatry (2007) 190: s51-s59. doi: 10.1192/bjp.190.5.s51
© 2007 The Royal College of Psychiatrists
Critical developments in the assessment of personality disorder
Peter Tyrer, MD and
Natalie Coombs, MSc
Department of Psychological Medicine, Imperial College, Charing Cross
Campus, London, UK
Fatema Ibrahimi, MRCPsych
St Mary's Psychiatric Training Scheme, London, UK
Anand Mathilakath, MRCPsych
West London Psychiatric Training Scheme, London, UK
Priya Bajaj, MRCPsych
St Mary's Psychiatric Training Scheme, London, UK
Maja Ranger, MRCPsych and
Bharti Rao, MSc
Department of Psychological Medicine, Imperial College, Charing Cross
Campus, London, UK
Raana Din, MRCPsych
St Mary's Psychiatric Training Scheme, London, UK
Correspondence: Professor Peter Tyrer, Department of Psychological Medicine, Imperial College,
St Dunstan's Road, London W6 8RP, UK. Email:
p.tyrer{at}imperial.ac.uk
Declaration of interest P.T. is Editor of the British Journal of
Psychiatry, but had no part in the assessment of this manuscript for
publication

ABSTRACT
Background The assessment of personality disorder is currently
inaccurate,
largely unreliable, frequently wrong and in need of
improvement.
Aims To describe the errors inherent in the current systems and to
indicate recent ways of improving personality assessment.
Method Historical review, description of recent developments,
including temporal stability, and of studies using document-derived
assessment.
Results Studies of interrater agreement and accuracy of diagnosis in
complex patients with independently established personality status using
document-derived assessment (PAS-DOC) with a four personality cluster
classification, showed very good agreement between raters for the flamboyant
cluster B group of personalities, generally good agreement for the
anxious/dependent cluster C group and inhibited (obsessional) cluster D group,
but only fair agreement for the withdrawn cluster A group. Overall diagnostic
accuracy was 71%.
Conclusions Personality function or diathesis, a fluctuating state,
is a better description than personality disorder. The best form of assessment
is one that uses longitudinal repeated measures using a four-dimensional
system.

INTRODUCTION
The assessment of personality and its range of abnormality,
a range that is
much greater than that implied by the conventional
label of `personality
disorder', is one of the critical elements
of a psychiatric examination.
However, it is frequently omitted
in clinical assessments, and even in
research studies it is
rarely assessed formally, even now, at a time when
personality
disorder is highly topical and its diagnosis possibly a reason
for
compulsory admission and treatment. When personality is
assessed it is often
done in a cursory and brief manner, and
again this extends to research
studies. Thus, for example, a
review of all the 152 original papers published
in the
British Journal of Psychiatry in 2005, revealed 13 (8.6%) in
which personality
assessment was at least part of the focus of the paper, in 5
of
which (3.3%) it was the main subject, and 14 other papers (9.2%)
in which
general psychopathology was assessed but personality
status was omitted. One
might have expected that most of the
papers addressing personality status
would have used a formal
assessment instrument. However, only 3 of the papers
did so.
These were: (a) a careful review
(
Cooke et al, 2005)
of cross-national
variations with the Psychopathy Check-list Revised
(
Hare, 1991);
(b) a study of
risk factors for repeated self-harm
(
Sokero et al, 2005),
which
used a structured interview for personality disorders (SCIDII;
Spitzer et al, 1987);
and
(c) an examination of personality comorbidity
(
Khan et al, 2005),
which
assessed personality by self-ratings using Cloninger's Tri-Dimensional
Questionnaire
(
Cloninger et al,
1991) and Eysenck's Personality Questionnnaire
(
Eysenck & Eysenck, 1975).
The
other two papers devoted to personality described new methods
of
assessment (
Bradley et al,
2005;
Thompson-Brenner &
Westen, 2005),
which reflects the low level of belief in existing
ones. Seven
of the studies merely used standard ICD (editions 810;
World Health Organization,
1992)
or DSMIIIR/DSMIV
(
American Psychiatric Association,
1994)
diagnoses of personality disorder from case records. Perhaps
the
most interesting revelation came from what is probably the first
structural
neuroimaging study of lying
(
Yang et al, 2005).
One might have
thought that this was a subject for which standard personality
assessment
would have been both natural and essential. However, the authors
felt
it necessary to construct a portmanteau instrument derived from
the
PCLR, DSMIV and an extra criterion for malingering.
It is hardly
surprising that the findings of the study (increased
pre-frontal white matter
in liars) has attracted a great deal
of attention when the authors are unable
to find an existing
rating instrument that can even make a passable attempt at
discriminating
liars from non-liars.
Nevertheless, there have been advances in the assessment of personality
disorder and currently a great deal is expected of it in terms of accuracy and
precision, particularly in forensic psychiatry. Indeed, a great deal was
expected of it in the past, particularly in military psychiatry during the USA
in the Second World War, but there it had a poor record of success and had to
be abandoned (Wessely,
2005).
Assessment is linked closely to classification and the two subjects need to
be discussed in tandem before examining ways of improving current assessment
strategies, particularly in the context of new forensic initiatives.

BRIEF HISTORY OF CLASSIFICATION AND ASSESSMENT
Classification of personality has a long history. Hippocrates
hypothesised
that all illness was a result of imbalance in the
four humours of yellow bile,
black bile, phlegm and blood, and
Galen extended this further to personality
by describing personality
types linked to excess of each of these: choleric
(yellow bile),
melancholic (black bile), phlegmatic (phlegm) and sanguine
(blood).
Although other attempts were made to formalise groupings of
abnormal
personality, they really did not attract any following
until Schneider
(
1923) formulated his famous
list of psychopathic
personalities that he conceptualised as distinct from
other
mental illnesses. He regarded the term `psychopathic' literally
(i.e. as
a pathology of mind) rather than as a synonym for `antisocial'
as was commonly
used by English-speaking writers. Schneider's
ten categories of psychopathic
personality were: hyperthymic,
depressive, insecure (sensitive and anankastic
sub-categories),
fanatical, attention-seeking, labile, explosive,
affectionless,
weak-willed and asthenic. Many of these have persisted in one
form
or another since 1923 and Standage
(
1979) found that the
asthenic,
explosive, depressive and affectionless were the most reliably
rated.
The current categories of dependent, impulsive (ICD only), depressive
(extended
DSM only) and schizoid are very similar to Schneider's descriptions
of
these four personalities.
When DSMIII was formulated
(American Psychiatric Association,
1980) two critical decisions were made. The first was to give
personality disorders a separate axis (Axis II) in the classification. The
official reason for this was a pragmatic rather than a scientific reason.
There was concern, probably justified in view of subsequent developments, that
the diagnosis of personality disorder would be forgotten when it competed with
other disorders. The unofficial reason was that the psychotherapists advising
the task force were very unhappy with much of DSMIII and were offered a
separate axis as a quid pro quo for accepting the main Axis I
descriptions. ICD10 (World Health
Organization, 1992) retained personality disorder on Axis I and
introduced Axis II for disability and function, so in this respect, and this
only, did it differ fundamentally from DSM. Which is right remains open to
much debate, and, after reviewing the arguments Kendell
(2002) wrote:
`This separation ensures that consideration is given to the possible
presence of disorders that are frequently overlooked when attention is
directed to the usually more florid Axis I disorders'
(American Psychiatric Association,
1980, p. 23).
`it is impossible to conclude with confidence that personality disorders
are, or are not, mental illnesses; there are ambiguities in the definitions
and basic information about personality disorders is lacking'.
The second decision was to use clearly defined operational criteria to
define the behavioural elements of personality disorder according to the 11
chosen categories in the classification. This was understandable in view of
the success of this approach in depression and schizophrenia, but was a
mistake with personality disorder. The main reason for the failure of the
classification was that the definitions of personality disorder used
heterogeneous descriptions, and when all their operational criteria were
assessed carefully their distribution was quite unlike that of DSM
(Livesley et al,
1994). The alternative of a dimensional classification, most
commonly based on traits rather than behaviour, existed before the
introduction of DSMIII and has been revised and reformulated many times
since (Persly & Walton,
1973; Tyrer & Alexander,
1979; Clark et al,
1996; Mulder & Joyce,
1997; Widiger & Simonsen,
2005), but only now is beginning to have a realistic possibility
of being adopted by the world community.
The dimensional system contemplates personality as a continuum, with normal
variation at one extreme and what is currently called personality disorder at
the other. The best fit is based on four dimensions which are not unlike the
original classification system of Hippocrates and Galen
(Table 1), particularly when
one realises that in the past `sanguine' or `full of blood' was synonymous
with confidence and stubborn determination, and `phlegmatic' was equivalent to
dull and cold indifference. There continues to be some debate over whether the
normal/abnormal personality continuum is best served by three, four or five
dimensions (Widiger & Simonsen,
2005), but a very strong case can be made for sticking to four to
maintain historical continuity as well as general accuracy
(Table 1).
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Table 1 Similarities between the four basic (higher order) dimensions of
personality as originally described by Hippocrates and Galen, with their
wording rephrased by subsequent
researchers
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In examining the assessment of personality disorder it is therefore
necessary to examine both dimensional and categorical approaches even though
at present both world classifications in psychiatry adopt the categorical
model of disorder. However, even if DSMV and ICD11 persisted
with the present unsatisfactory system, an alternative one would have to be
used to link with studies of normal personality and its variation. As Widiger
and Simonsen (2005, p. 126)
stated:
`even if the diagnostic manual does not explicitly include normal
personality traits, it should be closely coordinated with them so that the APA
diagnostic manual of personality disorders is itself well-integrated and
coordinated with basic science research on general personality structure'.
The first problem arising in the assessment of personality disorder is the
level of agreement between different systems of diagnosis. Others include the
stability (or, more accurately, the instability) of current assessment methods
in personality disorder, the problem of defining severity, particularly
relevant in forensic psychiatry, and the source of information for assessing
personality status.

ASSESSSMENT OF PERSONALITY DISORDER BY CATEGORIES AND DIMENSIONS
The first basic requirement of an assessment is that it should
be accurate.
Accuracy includes elements of both reliability
and validity. The latter is
often more difficult to determine,
as it requires a true measure of that which
is being measured,
and this genuine `gold standard' is very hard to find in
personality
research (
Cicchetti &
Tyrer, 1988). However, reliability,
the extent of agreement
between assessors (interrater or testretest
reliability) is an
essential first step. Zimmerman
(
1994) and
Clark &
Harrison (
2001) have carried
out an extensive review
of published studies and their results are similar.
Personality
is assessed by a combination of self-report questionnaires,
check-lists
and interviews, of which the structured interview is currently
considered
the most robust.
The best possible level of interrater reliability should therefore come
from a structured interview in which assessments are carried out jointly (i.e.
the same material is assessed by the two assessors). The disappointing level
of agreement shown in such settings is illustrated in
Table 2; only one study
(carried out with the interview schedule's creator;
Zanarini et al,
1987) reached the kappa agreement of 0.75 or above necessary to
confirm excellent agreement (Cicchetti
& Sparrow, 1981) for clinical purposes.
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Table 2 Summary of levels of agreement (kappa statistic with values for individual
diagnoses combined) in the assessment of personality pathology using DSM Axis
II structured interviews at joint interview (after
Clark & Harrison,
2001)
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However, the level of agreement for the presence or absence of personality
disorder is more satisfactory (Table
2), and this tends to be a uniform finding across a range of
studies (Bronisch & Mombour,
1994; Zimmerman,
1994, Clark & Harrison,
2001). The mean kappa values for the categorical diagnoses
(Table 2) hide tremendous
variation as agreement for individual diagnostic categories varies from 0.25
to 0.9. By contrast, when similar assessments are made using the dimensional
system the level of agreement tends to show agreement that is consistently
0.10.2 correlation points higher than categorical diagnoses
(Loranger et al,
1991; Vittengl et al,
1999). This even applies to individual traits. Thus, for example,
in a cross-national reliability study of the Personality Assessment Schedule
(PAS; Tyrer et al,
1984) the individual levels of agreement across the separate
ratings of 24 traits with both informant and participant interviews (i.e. 48
assessments) ranged from 0.52 to 0.94, with a mean agreement of 0.82
(informant assessment) and 0.75 (participant assessment)
(Cicchetti & Tyrer, 1988:
p. 71).
If these levels of agreement for categorical diagnosis are the best that
can be achieved in ideal research settings with generally cooperative patients
using instruments that take between 90 and 360 min to complete, it bodes ill
for their reliability in general clinical practice. The problems are made even
more profound by the lack of agreement between different instruments. There
are now over 60 different interview assessments and self-rated questionnaires
for personality disorder and cross-instrument reliability is remarkably poor.
Clark et al (1997)
found a grand median agreement of 0.27 (kappa) for comparisons of self-report
and interview assessments, even though these are allegedly addressing exactly
the same personality pathology.
So from these data we have a clear reason why researchers and clinicians
are not rushing to assess personality status in their patients, and, when they
do, why they use the diagnosis of `personality disorder not otherwise
specified' (PDNOS) most frequently
(Clark et al, 1995).
As two leaders in the field put it, `When researchers use different
instruments (interview or self-reports) to identify individuals with
personality disorder either in general or with a specific diagnosis
they may identify groups of individuals with substantially different
characteristics. This virtually guarantees that research results will not
replicate, despite the fact that the groups carry the same diagnostic label or
both scored highly on scales with similar names'
(Clark & Harrison,
2001).
The major reason for the poor agreement is clear, if the operational
criteria for individual diagnoses overlap then their identification will lead
to the diagnosis of several personality disorders, even when they may be
assessing the same single clear construct. The presence of multiple
personality disorders is euphemistically called comorbidity, implying the
presence of several independent disorders. However, when a diagnostic system
fails and splits a common condition into several, the outcome is still called
comorbidity when the correct term is consanguinity
(Tyrer, 1996). An attempt to
redress the confusion created by multiple personality disorders (a term that
also cannot be used as it has been appropriated by dissociative disorders in
the international classifications) is the cluster model. This has been used in
the DSM classification for many years
(Reich & Thompson, 1987)
and has the advantages of reducing the overlap a little, bringing the odd,
eccentric, withdrawn group (paranoid, schizoid and schizotypal; cluster A),
the flamboyant, erratic and dissocial group (antisocial, histrionic,
borderline and narcissistic; cluster B) and the anxious fearful group
(dependent, avoidant and obsessivecompulsive; cluster C), into more
natural groupings. However, to fit in well with the four-factor dimensional
model (Table 1) there should be
a fourth cluster (cluster D) devoted to the obsessional group alone.

CATEGORIES AND CLUSTERS OF PERSONALITY DISORDER
Although DSM experts give only the faintest of praise to the
cluster model
(Widiger, 2005) and it has not been endorsed by
ICD10, it is becoming
increasingly used (
Evans et al,
1999;
Bowden-Jones et
al, 2004;
Simeon et
al, 2004;
Bradley et
al, 2005;
Moran et
al, 2006) in both clinical and research studies because
it
simplifies what otherwise becomes a morass of comorbidity.
To use this with
ICD it is necessary to exclude schizotypal
from cluster A, narcissistic from
cluster B (but adding impulsive)
and renaming antisocial as dissocial and
obsessivecompulsive
as anankastic. The advantages of the cluster system
follow mainly
from its links to basic personality structure
(
Table 1) but
also can be
helpful in improving reliability, even though this
can only be a qualified
improvement as the basic disorders remain
unaltered. This is illustrated by a
recent comparison of the
reliability of a short assessment of personality
(Quick Personality
Assessment Schedule (PAS-Q;
Tyrer, 2000a) with a
longer structured
version based on ICD10 (PAS-I;
Tyrer, 2000b) in 72
patients
in an assertive outreach team. All had one or more prominent
mental
state diagnoses, as well as many personality disorders
(
Ranger et al, 2004),
and
approval for assessments of personality were agreed by the patients
and by
St Mary's Hospital Ethical Committee. Both assessments
were carried out by
M.R. using a clinical informant interview.
Informants had all known the
patients closely for at least 2
years) and to reduce carry over of information
assessments were
separated in time by a mean period of 9 months. The results
showed
the expected great variation in the reliability of individual
diagnoses
(kappa=0.260.70) (another reason for avoiding
use of these in clinical
practice) but somewhat greater agreement
(kappa= 0.40.78) for the three
clusters (
Table 3). In
general
the cluster B diagnoses tend to be rated more reliably
than cluster C as there
is less overlap between their clinical
features and those of other mental
illness. This overlap is
one of the main sources of difficulty when attempting
to improve
the accuracy of diagnosis
(
Tyrer et al, 1983;
Hassiotis et al,
1997).
With the separation of cluster D (inhibited or obsessional
group)
from cluster C the level of agreement is improved. For those
involved
in forensic assessment, the higher level of reliability
for dissocial
personality disorder is encouraging; the same
level of superior agreement has
been found in a forensic sample
(
Tyrer
et al, 2005a).
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Table 3 Agreement between two personality interviews (Quick Personality Assessment
Schedule (PASQ) and a longer version based on ICD10
(PASI)) separated by personality category, cluster and severity in 72
patients with severe mental illness tested a mean of 9 months
apart1
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INSTABILITY OF PERSONALITY ASSESSMENT
One of the main defining features of personality disorders in
both ICD and
DSM classifications is that they are `pervasive'
and `ingrained'. It now looks
as though this definition is also
wrong, as we now have abundant evidence that
personality status,
at least that assessed by our current instruments, is
unstable
(Paris,
2002,
2003;
Seivewright et al,
2002;
Shea et al,
2002;
Shea & Yen,
2003). Whereas in the past this lack of stability
was regarded as
a `contaminating' effect of mental state or
a poor assessing instrument, the
evidence now that it seems
to be universal has prompted a change in view. A
consistent
finding from all studies is that both in the short and longer
term
those patients who present for treatment with their personality
disorders show
a steady improvement (
Table 4).
This is generally
greater for those with borderline personality disorder than
others,
but in the Collaborative Longitudinal Personality Disorder Study
similar
improvement was found in all four personality disorders (borderline,
schizotypal,
avoidant and obsessivecompulsive) after 2 years, with
the
highest rate of remission being 61% in schizotypal personality
disorder
(regarded as belonging to the schizophrenias in ICD10)
and the lowest
50% in avoidant personality disorder (
Shea
et al, 2002;
Grilo
et al, 2004). However, in personal studies using a
self-rated
instrument for dependent personality
(
Tyrer et al, 2004)
dependent
personality features show greater stability
(
Seivewright, 2005).
In the
longer term we have very clear accumulating evidence
that borderline
personality disorder in a treatment setting
has a good outcome, but still have
to be aware that suicide,
the worst of outcomes, can occur at any stage, often
late in
the course of illness when the worst pathology seems to be over
(
Paris & Zweig-Frank,
2001).
The high level of instability of personality pathology, only a little less
than that of major depressive disorder and more so than anxiety
(Shea & Yen, 2003), has
led to doubts that current instruments, working as they do with a failed
classification system, do really indicate that personality is quite so
unstable (Wigider, 2005), and
there is also evidence of greater stability of social dysfunction in
longer-term studies (Nur et al,
2004; Seivewright et
al, 2004; Skodol et
al, 2005a; Tyrer
et al, 2005b). However, the genie is out of the
bottle. We can no longer plod forwards developing new instruments that we hope
will take us to the Holy Grail of temporal stability
(Tyrer, 2005a) and
refuse to accept that spontaneous change in personality features can take
place independent of any treatment effects.
However, in acknowledging the improvement in clinical samples being treated
for disorder we must also note that these populations are relatively uncommon
in epidemiological terms. Most individuals with personality disorder (3 out of
4) in contact with services are treatment resisting (Type R) rather than
treatment seeking (Type S; Tyrer et
al, 2003), and in the normal population this proportion is
even higher (C. Kirby, personal communication, 2007). Those with borderline
(mainly) and avoidant personality disorders (less prominently)
(Emmelkamp et al,
2006) are the ones involved in most of the recent studies,
although other approaches, particularly nidotherapy, which changes the
environment, not the patient (Tyrer,
2002; Tyrer & Bajaj,
2005), may be suitable for the Type R majority. The findings that
one in five children with abnormal personalities get worse in the Children in
the Community Study (Cohen et al,
2005) and that older people who have had anxiety and depressive
disorders in the past have a higher rates of cluster A personalities than when
young (Seivewright et al,
2002) is a reminder that personality pathology can go in different
directions. There is also evidence from epidemiological studies that cluster A
pathology persists into older age (Reich
et al, 1988).

MEASUREMENT OF SEVERITY OF PERSONALITY DISTURBANCE
Epidemiological studies suggest that between 5% and 13% of the
population
has at least one personality disorder
(
Casey & Tyrer, 1986;
de Girolamo & Reich, 1993;
Torgersen et al,
2001;
Coid et al,
2006a), so it is clear that it is a common condition.
It
is also equally apparent that some form of severity assessment
is necessary to
decide on priorities for management. This has
become increasingly necessary
when expensive provision is being
made for small groups, such as those in the
Dangerous and Severe
Personality Disorder (DSPD) Programme in England
(
Home Office & Department of Health,
1999).
The concept of dangerousness is often invoked when deciding
on
the severity of personality disorder, but this is mistaken.
Dangerousness
is not a function of personality disorder, as
it can be present with many
other mental disorders, or indeed,
in the absence of disorder.
Unfortunately there is no measure of severity of personality disorder in
the ICD or DSM classifications. This absence has caused significant concern,
as it is highly relevant to the planning and provision of services. What is
clear from empirical research studies is that those with more severe
personality disorder do not have stronger manifestations of one single
disorder as often postulated (Tyrer &
Johnson, 1996), but instead their personality disturbance extends,
ripple-like, across all domains of personality, so that in the most severe
disorders there is virtually no satisfactory personality function in any area
(Oldham et al, 1992;
Dolan et al, 1995;
Tyrer & Johnson, 1996). By
using this measure of severity, and by giving special attention to those with
marked antisocial personality features, thereby giving a separate level of
`severe personality disorder', it is possible to use the cluster system to get
a measure of severity and a reasonable level of agreement
(Table 3). This assessment is
also relevant in assessing those with the most severe personality disorders,
as there is some evidence of a different response in this group in high secure
settings (Tyrer et al,
2006).

PAS-DOC STUDY OF DOCUMENT-DERIVED PERSONALITY ASSESSMENT
Who provides the information for personality assessment is often
overlooked.
It is commonly assumed that the patient is the best source of
information
but, following the Robert Burns dictum, `O what gift would the
lordie
gie us, to see ourselves as others see us', a close informant
may be a
much more accurate judge. Although there is no clear
way of deciding whether
an informant's ratings are more accurate
than those of the patient
(
Zimmerman, 1994), the
additional
information derived from interviewing an informant can be extremely
valuable
(
Zimmerman et al,
1986), particularly if the informant is closely
related and is
female (
Brothwell et al,
1992).
However, the value of written records describing the patient's attitudes
and habitual behaviour has only been appreciated fully by one group, those who
measure psychopathy with the Psychopathy Checklist
(Hare, 1991). Although the
record of inter-rater reliability and predictive reliability of instruments
assessing personality disorder is disappointingly poor, the PCLR, and
its briefer fellow traveller, the screening version (PCLSV;
Hart et al, 1995) go
against the trend. These instruments attach great importance to written
records without which the full PCLR cannot be completed. The success of
the PCLSV in being the best single predictor of violence following the
discharge of a psychiatric patient from hospital
(Monahan et al, 2001)
is unlikely to result from just the presence of superior psychometric
properties; the bonus of the additional information derived from records is
almost certainly critical, and helps over other methodologies
(Moran et al, 2003).
This is also important when the data show that half of all people with
antisocial personality disorder show no significant violence
(Coid et al,
2006b).
We have developed a document-derived version of the PAS (PASDOC)
(Tyrer, 2005b) that
has the same underlying structure as the parent instrument
(Tyrer & Alexander, 1979)
but has been adapted for written records, including those about children and
adolescents. This latter process has been helped by the modification of the
original PAS for use in adolescents where it has been of value (Rangel et
al, 2000,
2003). In an extension of the
study of patients in the assertive outreach team we assessed both reliability
and validity of the PASDOC.
Reliability study
A single typed summary (2 pages) from the case notes of 20 patients
involved in the earlier study with patients in an assertive outreach team
(Table 3) was selected at
random by an independent administrator and given to two assessors (N.C. and
F.I.) who scored them independently using the PASDOC, which gives
personality status after completion of a computer algorithm. The dimensional
ratings of the four main clusters (A=withdrawn cluster, B=flamboyant cluster,
C=dependent cluster, D=inhibited (obsessional) cluster) were rated for
agreement using the intraclass correlation coefficient and also tested for
rater bias (Cicchetti et al,
1976). The results are shown in
Table 5. The best agreement was
reached for the obsessional cluster (RI=0.83), with the
cluster B group (RI=0.74) close behind. The scores for the
withdrawn cluster, A, showed the lowest level of agreement
(RI=0.41).
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Table 5 Levels of agreement between two raters assessing a single typed summary of
the 20 patients involved in the Document-Derived Version of the Personality
Assessment Schedule (PASDOC) study
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Validity study
The 20 patients examined in the reliability study were all very well known
to the clinical team and a consensus agreement of personality status had been
agreed and recorded. A team of five raters, who had received some prior
training only in the original PAS (this included N.C. and F.I. after they had
completed the reliability study and before their data were analysed), each
made an independent assessment of one volume of case notes (which contained
none of the research information on personality status) using the
PASDOC. In assessing the validity of the raters' assessments it was
assumed that a satisfactory assessment would make a correct decision as to
whether personality disorder was present and, if so, in which of the four
clusters it would be placed, or, in the case of more complex personality
disorders, which ones. Diagnostic accuracy was only regarded as positive if
both type and presence or absence of personality disorder were correct.
The results showed that overall diagnostic accuracy was 71%, cluster B
personalities were the most accurately identified (88%) and, in
contradistinction to the reliability study, cluster D (obsessional/inhibited
group) were the least well detected (47%). There was also considerable
variation in accuracy between the raters
(Table 6). In the context of
the results it should be emphasised that all 20 patients had complex pathology
(schizophrenia or schizoaffective disorder (11), bipolar disorder (5),
recurrent self-harm (1), psychotic depression (1), multiple phobias (1) and
obsessivecompulsive disorder (1), with 9 also having a history of drug
misuse).
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Table 6 Comparison of the accuracy for both personality type and disorder of the
Document-Derived Version of the Personality Assessment Schedule
(PASDOC) using masked assessment of one volume of case notes for 20
patients whose personality status had been determined independently by
consensus meetings of a clinical team.
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IMPLICATIONS FOR FUTURE ASSESSSMENT OF PERSONALITY
There are two main conclusions arising from this review of studies
and
recent experimental work. The first is that personality
and its disorder can
no longer be regarded as a clear and stable
entity that will yield eventually
to the right form of assessment.
What can be assessed accurately at a point in
time is personality
function, not disorder. Just as mental state can be
dependent
on environmental influences, so can personality status, and
this can
be made use of in therapy (
Tyrer,
2002;
Tyrer & Bajaj,
2005).
The notion of personality function, first expressed clearly
by
Bronisch & Klerman
(
1991), has been confirmed by
recent
studies showing that personality functions in different ways
at
different ages and in response to different needs. At the
same time we must
also recognise that there are some underlying
characteristics, best described
as traits, which do show some
tendency to stability, but it must be
acknowledged that this
is not an absolute tendency and cannot be allowed to
form the
only prediction of the future. At the same time it should not
be
ignored, as although personality assessment is still defective,
it is still a
strong predictor of outcome when present with
other mental disorders
(
Newton-Howes et al,
2006).
The second conclusion is that a revision of the current classification of
personality disorder is overdue. Any changes must take account of the abundant
evidence that normal and abnormal personalities merge into each other and it
is not appropriate to have one classification for normal variation and another
for pathological variation. It is suggested here that four dimensions cover
the range of normal and abnormal pathology and that this is the best
separation available.
In future, for better assessment we need to have improved global
assessments of personality status that can be applied across all age-groups.
At present, many investigators, particularly in assessments of children and
adolescents, are compelled to pick one aspect of personality functioning at
the neglect of others and this may lead to different results between
investigators. Thus the study by Viding et al
(2007, this issue) describing
the significance of callousunemotional traits in the onset of conduct
disorder, would be helped greatly by having a much greater breadth of
personality assessed, not least because the presence of some more adaptive
traits may alter the progression of the maladaptive ones. Similarly, the
follow-up of the Aberdeen Children's cohort has had to rely on the Rutter
Scale (Rutter, 1967) for
recording personality pathology in the flamboyant cluster
(Wiles et al, 2005),
something that was unlikely to have been anticipated by its originator. In
other childhood studies, such as those in which internalising and
externalising features are examined
(Fergusson et al,
2006), grouping these features by personality status might help to
explain much of subsequent pathology
(Mervielde et al,
2005; Westen et al,
2005). At the very least this hypothesis should be tested.
With greater awareness of the variability of personality function over time
it is also necessary to take more notice of written and other independent
evidence about personality status at successive points in time. At present,
reliability remains hamstrung by the deficiencies of the current
classification, so all attempts to meld and merge diagnoses are bound to fail
to some extent because the building blocks are faulty. However, the results
with the PASDOC suggest that personality pathology in the flamboyant
and antisocial group can, as with the PCLR, be rated both reliably and
accurately, but this is more difficult for those aspects of pathology that do
not `hit the headlines' as it were, and are confined to more private settings
where documentation is poor.
These problems need to be resolved. The work described here suggests that
they are being addressed, and this is essential if clinicians are to feel
confident about diagnosing clinical problems comprehensively, planning care
and predicting outcome for the disorders they commonly treat.

ACKNOWLEDGMENTS
We thank Sandra O'Sullivan for help in organising the selection
of notes
and papers, Drs Andrew McDonald & Katarina Miloseska
for coordinating the
reliability studies, and the patients and
members of the Paddington Outreach
Rehabilitation Team (PORT)
and Community Outreach Rehabilitation Team (CORT),
Central North
West London Trust for their good-natured cooperation. This work
was
partly funded by a grant from the National Programme on Forensic
Mental
Health.

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