Background: We investigated whether melancholic and non-melancholic Japanese depressive patients differed in regard to a personality feature, interpersonal sensitivity, as measured by the Interpersonal Sensitivity Measure (IPSM).
Methods: In addition to 154 normal controls, 66 remitted melancholic patients and 55 remitted non-melancholic patients filled out the IPSM and two widely-used comprehensive personality inventories, the Temperament and Character Inventory (TCI) and the Munich Personality Test (MPT). The subdivision of patients was made according to three major symptom-based criteria for melancholia (those of RDC, DSM-III, DSM-IV).
Results: Multivariate and post-hoc univariate analyses of variance revealed significant differences among the three groups in several personality dimensions after Bonferroni's adjustments of P values. While reported scores of both melancholic and non-melancholic patients deviated from normative scores on several personality dimensions, non-melancholic patients reported significantly higher scores on the total IPSM and the 'fragile inner-self' (a subscore of the IPSM) than did normal controls or melancholic depressives. The principal component analysis isolated two factors related to depressive disorders: one factor corresponding to the five IPSM scores; and the other corresponding to harm avoidance, neuroticism and frustration tolerance. The scores on the former factor differentiated non-melancholic depressives from melancholic depressives and normal controls. The scores on the latter factor differentiated both melancholic and non-melancholic depressives from normal controls.
Limitations: Prospective studies in which depressive subjects are subdivided into melancholic and non-melancholic subjects will be required to see whether the personality deviations here related to depressive disorders strongly reflect the premorbid personality function.
Conclusions: These results indicate that the IPSM scales (particularly, the fragile inner-self scale and the total IPSM scale) are relatively independent of all dimensions included in the two comprehensive personality inventories, and have a capability to describe personality differences between non-melancholic depression and melancholia.