Background. Self-report instruments assessing the DSM
disorders are characterized by
overdiagnosis due to their emphasis on the measurement of personality traits
rather than the
impairment and distress associated with the criteria.
Methods. The ADP-IV, a Dutch questionnaire, introduces
an alternative assessment method: each
test item assesses ‘Trait’ as well as ‘Distress/impairment’
characteristics of a DSM-IV criterion.
This item format allows dimensional as well as categorical diagnostic
evaluations. The present study
explores the validity of the ADP-IV in a sample of 659 subjects of the
Results. The dimensional personality disorder subscales,
measuring Trait characteristics, are
internally consistent and display a good concurrent validity with the Wisconsin
Disorders Inventory. Factor analysis at the item-level resulted in
11 orthogonal factors, describing
personality dimensions such as psychopathy, social anxiety and avoidance,
negative affect and self-image. Factor analysis at the subscale-level identified
dimensions, reflecting hostile (DSM-IV Cluster B) and anxious (DSM-IV Cluster
interpersonal attitudes. Categorical ADP-IV
diagnoses are obtained using scoring algorithms, which emphasize the
Trait or the Distress concepts
in the diagnostic evaluation. Prevalences of ADP-IV diagnoses of any personality
according to these algorithms vary between 2·28 and 20·64%.
Conclusions. Although further research in clinical samples
is required, the present results support
the validity of the ADP-IV and the potential of the measurement of trait
and distress characteristics
as a method for assessing personality pathology.