Invited Lecture

auf der 7. Arbeitstagung

der Fachgruppe Differentielle Psychologie, Persönlichkeitspsychologie und Psychologische Diagnostik

29.9. – 30.9.2003, in Halle

 

Differentiating Normal, Abnormal, and Disordered Personality

 

John Livesley

(Department of Psychiatry, University of British Columbia)

 

Interest in the interface between normality and psychopathology was renewed with the publication of DSM-III more that twenty years ago.  The use of a separate axis to classify disorders of personality brought increased attention to these conditions. At the same time, the definition of personality disorder as inflexible and maladaptive traits stimulated interest in the relationship between normal and disordered personality structure and functioning. Although the DSM and ICD classifications continue to make categorical distinctions among disorders and between disorder and normality, there is growing dissatisfaction with this model and recognition that future classifications need to incorporate the dimensional perspective of traditional trait theory. This further emphasizes the importance of differentiating normal, abnormal, and disordered personality, and raises the question of whether models of normative personality structure can be extended to classify disordered personality.

The evidence suggests that traits delineating personality disorder are extremes of normal personality traits and that the structural relationships among these traits resemble the structures described by trait theories. On the basis of this evidence, it will be suggested that a trait model should be adopted to represent clinically important dimensions of individual differences in future classifications.  However, it will also be argued that these models in themselves have limitations when differentiating between normal and disordered personality.  Although an extreme score on a trait dimension is abnormal in the statistical sense, it does not invariably imply the presence of disorder.  Additional criteria are needed to determine whether this is the case. Possible criteria will be reviewed and their relationship to normal personality functioning will be discussed.