IPDE - Extranet Systems - World Health Organization

53 Experiences with IPDE
The investigators considered three solutions: (1) to administer the interview
in two sessions; (2) to create separate modules for the ICD-10 and
DSM-III-R PDs; and (3) to screen cases with a questionnaire with a low
rate of false-negatives, thereby eliminating interviews with subjects
unlikely to have a PD diagnosis.
Another question raised by some respondents concerned the duration
of the behaviour used to define PD. ICD-10 and DSM-111-R do not specify
the exact duration of the abnormal behavioural patterns constituting
PDs, but both classifications use the term 'long-term'. ICD-10 states that
the abnormal behaviour 'is stable and of long duration, having its onset
in late childhood or adolescence,' while DSM-III-R says that it is 'characteristic
of the persons's recent (past year) and long-term functioning
(generally since adolescence or early adulthood).' There is some discrepancy
then between ICD-10 and DSM-III-R regarding the onset of
the maladaptive behaviour. The IPDE solved these problems by requiring
that the behaviour associated with almost all the diagnostic criteria
be present for at least five years, and at least one of the criteria be evident
before age 25, in order to diagnose that disorder.
Concern was also expressed that a patient might have a disorder like
depression that gives a distorted image of what heishe is usually like. A
patient may also be unaware of some traits or unwilling to acknowledge
them. The influence of depression is a well known problem in the evaluation
of PD by self-report. A previous study with the PDE showed little
influence of anxiety or depression on the categorical or dimensional
assessment of PD.S It may be reasonable to conclude the same for IPDE
if experienced clinicians carefully question the patients and use their
clinical judgement. Severely depressed patients, however, might have
difficulties in remembering their habitual state due to the effect of
depression. An alternative solution is to postpone the PD examination
until the patient is euthymic m to interview a relative. Lack of awareness
or lying about unfavourable or less socially acceptable behaviour is a
general problem in diagnosing mental disorders, and is not peculiar to
stmcture.d interviews. Although the questions flow naturally, they presume
that the subject is attentive, of normal intelligence, and motivated.
What are specific points with regard to applicability of IPDE in your
culture?
Before the study several interviewers were concerned that the IPDE
might reflect North American attitudes and social and cultural norms