Rep36 Understanding Personality Disorder

3.1.2 Choosing a structured assessment
Interview-based assessments are considered the
‘gold standard’ for diagnosing personality
disorders (Clark & Harrison, 2001). However,
problems may be encountered in the
reconciliation of conflicting information
reported in interview and derived from collateral
sources. Self-report instruments are thought to
have validity in the broader assessment of
personality traits but are of less use in personality
disorder diagnosis; self-report instruments tend
3. Psychological interventions for individuals
with personality disorder

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to yield higher prevalence estimates for Axis II
disorders when compared with interview
methods (Dolan-Sewell 
et al
., 2001), and consist
of a series of uncorroborated statements or self-
presentations made by the client (Hart, 2001).
Recent research suggests that, in forensic
populations at least, interview and self-report
methods in fact perform equally well in the
assessment of personality disorder characteristics,
although assessment methods may be
differentially sensitive to the personality disorder
problems being examined (Blackburn, Donnelly,
Logan & Renwick, 2004). That is, traits reflecting
beliefs about the self or others may be reliably
assessed by self-report questionnaires due to
respondents’ access to autobiographical memory.
In contrast, stylistic traits involving undesirable
effects on others may be evaluated more
adequately by means of semi-structured interview
methods (also Clark & Harrison, 2001).
Semi-structured interviews for the assessment
of personality disorders may be organised by
topic or domain (e.g. the International
Personality Disorder Examination or IPDE;
Loranger, 1999) or by disorder (e.g. the
Structured Clinical Interview for DSM-IV Axis II
Disorders or SCID-II; First 
et al
., 1997). The
arrangement of criteria by diagnosis facilitates
rater judgement as to whether a particular
characteristic exemplifies a core characteristic of
the target disorder. However, the weakness of
this approach is the potential for biased
judgement or the ‘halo’ effect. For example, if a
client has a positive rating on the first two or
three criteria for a particular personality
disorder diagnosis, the clinician may not rate
subsequent criteria with appropriate objectivity
and instead under-probe items in a possibly
unconscious attempt to confirm the initial
diagnostic impression (Clark & Harrison, 2001).
The arrangement of interview items by topic is
thought to give a more natural interview because
it facilitates client reflection on various life
domains (e.g. employment, self, interpersonal
relationships), much as they would in ordinary
discourse. Strong empirical data supporting the
validity of one format over the other is so far
absent and the choice would appear to be largely
a matter of the preference or theoretical
predilection of the clinician.