[PerCaDim study: relationship between categorical and dimensional approaches of personality]

Purpose: Personality and its disorders have been the subject of many studies in philosophy, psychology or medicine. Current nosology gives preference to categorical classifications, but a dimensional approach may also be considered. Supported by Cloninger's psychobiological model, it refers to concepts of temperament (novelty seeking, reward dependence, harm avoidance and persistence) and character dimensions (self-directedness, cooperativeness and self-transcendence). Categorical and dimensional approaches do not appear antinomic, and the PerCaDim study tries to verify the hypothesis of correlations existing between them.

Subjects and methods: One hundred and eleven patients completed two personality inventories. The dimensional approach was assessed using the TCI-125 (short version of the Temperament and Character Inventory) (Cloninger et al., 1993 [9]), which includes four dimensions of temperament and three dimensions of character. The categorical approach was assessed using Vragenlijst Kenmerken voor van de Persoonlijkheid (VKP) (Duijsens et al., 1993 [15,16]), which defines personality disorders according to DSM III-R (APA, 1987 [1]).

Results: The PerCaDim study reveals significant relationships between the dimensions of temperament and character and personality disorders. For dimensions of temperament: novelty seeking is correlated negatively with schizoid personality and positively with antisocial, borderline, histrionic, narcissistic and sadistic personalities. Ten out of 13 personalities from DSM III-R are positively correlated with harm avoidance. Cluster A and obsessive-compulsive personality disorders have negative correlations with reward dependence, whereas five pathological personalities have positive correlations with persistence. For dimensions of character: all personality disorders are negatively correlated with self-directedness. Cooperativeness is negatively correlated with six personality disorders. Among the dimensions of character, only self-transcendence has positive correlations with personality disorders.

Discussion: The PerCaDim study highlights various relationships between dimensional and categorical approaches of personality. It shows negative correlations between reward dependence and cluster A personality disorders, positive correlations between novelty seeking and cluster B personality disorders and between harm avoidance and cluster C personality disorders. Self-directedness and cooperativeness character's dimensions seem to reflect the subject's adaptation, because negative correlations were found with all personality disorders. It may be surprising that correlations appear positive between self-transcendence dimension and 12 personality disorders. This result is not striking for "psychotic" personalities, but may be questionable for other personalities.

Conclusion: These results confirm previous findings that Cloninger's dimensions can objectify personality disorders. Few dimensions of the Temperament and Character Inventory can be considered as vulnerability factors. The use of the Temperament and Character Inventory will most certainly be of good help in the future to detect or prevent a personality disorder in some subjects at risk.